2010+13+Shear

合集下载

墨尼克公司产品介绍课件

根据伤口渗液情况更换，一般1-3天更换注意：冲洗干净，勿残留
E:上皮化的保护文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
肉芽健康:美皮康肉芽干燥:美诺佳+美皮康超薄肉芽水肿:美盐+美皮康(可加压包扎)
图片
伤口分期处理原则文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
美皮康银结构与功能
透气防水防菌吸收渗液 & 杀菌抗感染
聚氨酯薄膜被衬
聚氨酯泡沫垫+ 银 Ag2SO4
美皮康银 Mepilex Ag
无创揭除 & 减轻疼痛
Safetac®软聚硅酮层
- 30分钟内快速起效杀菌 - 杀菌效果持续7天
1、美皮康银：无痛无创、渗液管理、有效杀菌文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
E
藻酸盐敷料（美即爽）水凝胶（美诺佳）美皮康
水凝胶（美诺佳）美皮康
四：疤痕解决方案——美皮护文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
瘢痕预防和治疗敷料文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。美皮护® (Mepiform)
M:渗液管理文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
美即爽
美诺佳
创面/肉芽干燥时使用
美即爽成分：藻酸钙钠纤维文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。
（止血，吸收渗液，促进肉芽生长）适应伤口：窦道引流、清创后出血的伤口、脂肪液化的伤口、肛瘘术后及鼻窦手术后等

Shear behaviour of a geogrid-reinforced coarse-grainedsoil based on large-scale triaxial tests

Shear behaviour of a geogrid-reinforced coarse-grained soil based on large-scale triaxial testsXiaobin Chen a,*,Jiasheng Zhang a,Zhiyong Li ba School of Civil Engineering,Central South University,22Shaoshan Road,Changsha410075,PR Chinab Human Communication Research Institute,472Fu Rong Road,Changsha410008,PR Chinaa r t i c l e i n f oArticle history:Received20June2013Received in revised form7May2014Accepted7May2014Available online2June2014Keywords:Weathered mudstone coarse-grained soil Geogrid reinforcementLarge-scale triaxial testShear behaviourReinforcement coefﬁcientSlip surface a b s t r a c tIn China,weathered mudstone geogrid-reinforced coarse-grained soil is used extensively for road em-bankments.However,the microstructure and disintegration process of weathered mudstone remain unclear.Furthermore,few studies have investigated the shear behaviour of this kind of geogrid-reinforcedﬁll through large-scale triaxial tests against grain size effects.To bridge this gap,this study reports results from large scale consolidated undrained(CU)and consolidated drained(CD)triaxial tests as well as scanning electron microscopy(SEM),energy-dispersive X-ray(EDX),and disintegration tests on weathered mudstone geogrid-reinforced coarse-grained soil.EDX spectrograms and SEM images show that coarse grains disintegrate rapidly mainly owing to the high clay mineral content and loose microstructure.Therefore,a suitable disintegration time(w15days)is recommended for embankment sits.The shear behaviour of this geogrid-reinforcedﬁll is investigated in detail through large-scale triaxial tests.The shear deformation tends toward strain hardening behaviour with an increase in the number of geogrid layers and the conﬁning pressure.Geogrids signiﬁcantly improve the apparent cohesive strength of coarse-grained soil.The pore water pressure is found to develop rapidly in the0% e4%axial strain phase but dissipate slowly in the4%e12%axial strain phase.During shear,the pore pressure coefﬁcient A values of0.2e0.4are indicative of the partial saturation of specimens.Conse-quently,pore water pressure development is mainly attributed to the movement and rearrangement of coarse particles in coarse-grained soil.Experimental data show that the geogrid-reinforcement co-efﬁcients increase with the number of geogrid layers,and a20-cm separation between geogrid layers is recommended for embankment construction sites.The number of geogrid layers inﬂuences the geogrid e soil interface’s mobilization and the slip surface type.Test results revealed three types of slip surfaces related to the failure shapes of specimens.Then,based on CU experimental data,the parameters of the Duncan e Chang constitutive model are discussed.Ó2014Elsevier Ltd.All rights reserved.1.IntroductionMudstone,which is widely distributed in the southern part of China,is an extremelyﬁne-grained sedimentary rock consisting of a mixture of clay and silt-sized particles,generally a mixture of clay minerals with any or all of quartz,feldspar,and mica.Mudstone can be subdivided into siltstone and claystone,in which more than50% of the composition is silt-and clay-sized particles,and both of which have similar mechanical properties.Mudstone is a soft rock, commonly with uniaxial compressive strengths less than15MPa and density less than2.65g/cm3.Therefore,it is generally too soft for construction or similar purposes.However,when naturally weathered,it breaks into blockyﬂakes and eventually into residual coarse-grained soil,which is often used as aﬁll for constructing embankments in mountainous areas in China.In recent years,geosynthetics,especially geogrids and geo-textiles,have been increasingly used to reinforce embankments.A geogrid-reinforced embankment,by preventing lateral deforma-tion and distributing trafﬁc loading over a larger subgrade area,can often carry higher trafﬁc loading(U.S.Army Corps of Engineers, 2003).Therefore,when weathered mudstone coarse-grained soil are used in highway embankments subjected to trafﬁc loading,they are usually reinforced with geogrids in top layer.In this study,the shear behaviour and inﬂuences of geogrid reinforcement on clayey mudstone coarse-grained soil are investigated in detail through large-scale triaxial test results.*Corresponding author.Postal address:22Shaoshan Road,Changsha410075, Hunan province,China.Tel./fax:þ86731-82656812.E-mail addresses:cxb528@,chen_xiaobin@,chenxb@illinois. edu(X.Chen).Contents lists available at ScienceDirectGeotextiles and Geomembranesjou rna l homepage:/locate/geotexmem/10.1016/j.geotexmem.2014.05.0040266-1144/Ó2014Elsevier Ltd.All rights reserved.Geotextiles and Geomembranes42(2014)312e328Many studies have investigated granular soil(or granular mixture)reinforcement mechanisms through laboratory andﬁeld tests.Giroud and Noiray(1981)used geogrids and woven geo-textiles as reinforcements for increasing resistance to trafﬁc load. They,along with many other studies(Berg et al.,2000;Hufenus et al.,2006;Subaida et al.,2009),concluded that geogrids mainly provide reinforcement through lateral restraint,improved bearing capacity,and the tensioned membrane effect.Giroud and Han (2004a,b)presented a design method for geogrid-reinforced un-paved roads in which the inﬂuences of the bearing capacity factor (Nc)and interlock among the geogrids were considered.Mekkawy et al.(2011)investigated the shoulder rutting performance of geogrid-reinforced granular shoulders on soft subgrade by per-forming laboratory and full-scale tests.They presented a design chart correlating the rut depth with the number of load cycles to subgrade CBR.This chart was used to optimize granular shoulder design parameters and better predict granular shoulder perfor-mance.Palmeira(2009)analysed the results of large-scale cyclic and monotonic loading tests of unreinforced and geosynthetic-reinforced unpaved roads.They found that the presence of a rein-forcement layer signiﬁcantly reduced the magnitudes of vertical stress increments transferred to and vertical strain in the subgrade. Their experimental investigations showed that geogrids were more efﬁcient than geotextiles in restraining lateral movement of theﬁll material.Perkins and Ismeik(1997a,b)also noted the beneﬁcial effects of geosynthetics on reinforced pavements and unpaved roads.Anderson and Killeavy(1989)and Cancelli et al.(1992)noted that the use of geosynthetic reinforcements could reduce pavement thickness by20%e50%.Knapton and Austin(1996)achieved rut depth reductions of up to50%by using geosynthetic re-inforcements,especially geogrids.Raymond and Ismail(2003) noted that the reinforcement layer position inﬂuences a road’s performance.Yang et al.(2012)conducted accelerated pavement tests on unpaved road sections with geocell-reinforced sand bases and demonstrated that the NPA geocell signiﬁcantly improved the stability of unpaved roads with sand bases and reduced permanent deformation.Gourc et al.(1986)proposed a displacement evalua-tion method based on the effect of reinforcement extensibility on the mobilization of interface mechanisms of fabric-retaining walls. Skinner and Rowe(2005)studied the stability of geosynthetic-reinforced retaining walls by analysing a geosynthetic-reinforced soil wall supporting a bridge abutment and approach road con-structed on clayey soil deposit.Ehrlich et al.(2012)presented a physical model study of the inﬂuence of compaction on the behaviour of geogrid-reinforced soil walls.Their results showed that the position of maximum tensile force mobilized in the re-inforcements was nearer to the face in the wall with heavy compaction.Weggel and Ward(2012)presented the equations for a numerical model that describes the accumulation ofﬁlter cake on a geotextile asﬂow passes through and solved them numerically using an Eulerﬁnite difference scheme and an Excel spreadsheet. Sitharam and Hegde(2013)discussed the geotechnical problems at a site,the design of a geocell foundation based on experimental investigation,and the construction sequences of geocell founda-tions in theﬁeld.Yang et al.(2014)focused on soil-rock mixtures as the backﬁlls of geogrid-reinforced soil retaining walls with due concern for their long-term performance and safety.Wang et al. (2014)conducted a numerical compound tensile test(in sand) with one geogrid tensile member by PFC2D to investigate the load transfer behaviour between the geogrid and sand.Moraci and Recalcati(2006)used a large-scale pullout test setup to study the factors inﬂuencing the behaviours of geogrid reinforcements embedded in granular soil and evaluated the peak and residual pullout resistance values.Fannin et al.(2005)and Chakraborty and Salgado(2010)studied the dilative behaviour of granular soil.The shear behaviour at the geotextile e granular soil interface inﬂuences the stability of a geotextile-reinforced embankment. Many studies conducted direct shear tests on various geotextile interfaces to study their shear stress e shear displacement re-lationships(Gilbert et al.,1996;Triplett and Fox,2001;Zornberg et al.,2005;Bergado et al.,2006;Nye and Fox,2007;Sharma et al.,2007;Suksiripattanaponga et al.,2013).Tran and Meguid (2013)developed a coupledﬁnite-discrete framework to investi-gate the behaviour of a biaxial geogrid sheet embedded in granular material and subjected to pullout loading.Esmaili et al.(2014) presented the descriptions and results of multi-scale pullout and interface shear tests on a woven polypropylene geotextile rein-forcement material in a marginal quality soil.Khoury et al.(2011) presented the results of a laboratory study on the mechanical behaviour of unsaturated soil e geotextile interfaces using a specially modiﬁed direct shear apparatus.Belén et al.(2011)stud-ied the frictional behaviours of geosynthetics used in municipal solid-waste landﬁlls and developed an analytical model to describe the shear behaviour and simulate progressive geomembrane e geotextile interface failure from direct shear tests.Sayeed(2014) used large-size direct shear tests to determine the interfacial shear characteristics of sand e geotextile under three different normal stresses.They investigated the surface morphology of sand particles based on SEM images and quantitatively analysed it using the Wadell roundness and degree of angularity methods.Pitanga et al.(2009)investigated geogrid-reinforced granular soil and found very low dilatancy values between1/300and1/50of the maximum shear displacement in addition to a nonlinear failure envelope in the normal stress ranges.Stark et al.(1996)and Hebeler et al.(2005)studied the geogrid interface interaction mechanisms based on shear tests and found that interbedding and hook control the interface shear strength.Gilbert et al.(1996)and Sharma et al. (2007),among others,developed interface interaction models toﬁt experimental data.Indraratna et al.(2006,2007),among others, demonstrated the effectiveness of geogrid reinforcements on restricting ballast deformation throughﬁeld tests and simple lab-oratory tests.Coleman(1990)and Shukla and Yin(2006)evaluated the effects of interlocking between railway ballast and geogrid apertures on shearing resistance.Indraratna et al.(2011)described how the ballast e geogrid interface copes with fouling by coalﬁnes. They investigated the stress e displacement behaviours of fresh, fouled,and geogrid-reinforced ballast by performing a series of large-scale shear tests.Dombrow et al.(2009)conducted a series of large-scale shear tests with fresh ballast and ballast fouled by coal to varying degrees.They found that the shear strength decreased steadily as the fouling percentage increased.Tutumluer et al.(2012) studied the shear behaviour of ballast under monotonic and cyclic loading.Chen and McDowell(2012)used the discrete element method to simulate the cyclic loading of geogrid-reinforced ballast under conﬁned and unconﬁned conditions.Leshchinsky and Ling (2013),based on prior large-scale laboratory tests of ballast em-bankments with geocell conﬁnement and relevant numerical modelling,validated an acceptable material model for a parametric study usingﬁnite element analysis to investigate the effects of geocell conﬁnement on ballasted embankments when encoun-tering a soft subgrade,weaker ballast,or varying reinforcement stiffnesses.Indraratna et al.(2013)described a novel large-scale process simulation test(PST)apparatus that can capture the lateral strain variation upon loading.They conducted laboratory tests to explore the deformation and degradation response of both unreinforced and reinforced ballast under high-frequency cyclic loading.For coarse-grained soils,Pitman et al.(1994)focused on the ef-fect of the coarse grain content on soil de et al.(1998) investigated the effect of the coarse grain content on theX.Chen et al./Geotextiles and Geomembranes42(2014)312e328313collapsibility of a granular mixture.Vallejo and Mawby (2000)conducted some tests to study the shear strength at different coarse grain contents.Dash and Sitharam (2009)investigated the stress e strain relationships of coarse grained soil,and Bandini and Pham (2011)focused on the critical state characteristics of the same.Zhao and Zhang (2013a,b)conducted drained and undrained triaxial tests on several widely graded soils with different coarse contents at low con ﬁning stress.They found that the soil micro-structure changes from a ﬁne-to a coarse-controlled structure beyond a critical coarse content of w 70%.Zhao and Zhang (2013a,b)investigated the microstructure,compressibility,and shear strength of an unsaturated widely graded coarse-grained soil.Suksiripattanapong et al.(2013)studied the pullout resistance of geogrid reinforcement in coarse-grained soils and presented pullout resistance equations for the bearing reinforcement with different dimensions and spacings between transverse members.Demir et al.(2013)conducted 16ﬁeld tests to evaluate the effects of replacing natural clay soil with a stiffer granular ﬁll layer and single-multiple layers of geogrid reinforcement placed into the granular ﬁll below circular footings.Moraci and Cardile (2012)analysed the effects of the tensile cyclic load,frequency,and amplitude;vertical con ﬁning stress;and geogrid structure on the pullout behaviour in terms of accumulated displacements and deformations.Shivashankar and Jayaraj (2014)investigated the effects of prestressing the rein-forcement on the strength improvement and settlement reduction of a reinforced granular bed overlying weak soil.Many studies have investigated the effect of the coarse grain content on the stress e strain relationships,shear strength,and critical state properties of coarse grained soil.However,few studies have focused on geogrid-reinforced coarse-grained soils;in particular,few large-scale triaxial experimental investigations have been rge specimens are rarely used to diminish coarse grains ’size effects on the shear behaviour in triaxial tests.Furthermore,the disintegration of coarse grains is always neglec-ted.To better understand the shear behaviour and effects of geogrid-reinforced coarse-grained soil during triaxial testing,a series of large-scale triaxial tests (CU and CD)were conducted in this study.SEM images and EDX spectrograms of mudstone were obtained using a ﬁeld-emission gun environmental scanning elec-tron microscope (FEG-ESEM).In addition,disintegration tests were conducted to investigate the mudstone grain ’s disintegration when exposed to air and water.In the triaxial experiments,the di-mensions of each specimen are as follows:diameter ¼300mm,height ¼600mm,and thickness of rubber membrane encasing specimen ¼2mm.The relationships between the specimen failure shapes and numbers of geogrid layers were studied,and the pa-rameters of the Duncan and Chang constitutive model were discussed.2.Materials and specimen preparation 2.1.Mudstone grain ’s propertiesMudstone consists of silt-,mud-,and clay-sized particles.The chemical compositions of mudstone grains are summarized in Table 1.The microstructure of the mudstone grain ’s mineral matrix was investigated by SEM,as shown in Fig.1(a e d).These images show that the microstructure of the mudstone grain ’s mineral matrix is relatively loose,and the shape of the clay ’s mineral matrix is mainly blocky and laminated.The loose microstructure suggests that water and air could easily penetrate the mudstone grains,in turn easilyTable 1Chemical compositions of mudstone grains (%,percentage by dry weight).Sample no.Compositions S i O 2Al 2O 3Fe 2O 3CaO MgO Burning loss Others A1(at k6þ060)65.0514.537.80.74 1.647.32 2.92A2(at k14þ130)69.3413.587.270.54 1.13 5.23 2.91A3(at k17þ090)67.2014.057.510.65 1.20 6.86 2.53A4(at k23þ400)69.5013.987.400.55 1.32 4.75 2.50Average67.7714.047.500.621.326.042.71Fig.1.SEM images of weathered mudstone.X.Chen et al./Geotextiles and Geomembranes 42(2014)312e 328314Fig.2.EDX spectrums of weathered mudstone.X.Chen et al./Geotextiles and Geomembranes 42(2014)312e 328315leading to their disintegration.The main minerals in the mudstone grains were analysed based on the EDX spectrograms obtained using an FEG-ESEM,as shown in Fig.2(a e d).The EDX spectrum analysis shows that the minerals in the mudstone grains mainly include clay,quartz (50%e 58%),chlorite (15%e 18%),isinglass (14%e 18%),and feldspar (11%e 12%)by weight.Among these,clay-type minerals d including chlorite,isinglass,and feldspar d constitute 40%e 48%.These fractions can easily be weathered into clayey ﬁne soil.When mudstone grains are exposed to air and water,they disintegrate quickly mainly owing to their high clay mineral con-tent.This disintegration is probably bene ﬁcial for constructing geogrid-reinforced embankments because ﬁlls with higher density and degree of compaction can be obtained with the same compaction energy.In this study,the disintegration time and its effects on mudstone grains were investigated through tests.The disintegration test involves the following steps:(1)Weatheredmudstone grains are dried in an electronic oven.(2)Particle size distribution analysis tests are performed using different sieve aperture diameters (63,37.5,19,9.5,2.36,0.6,and 0.3mm),and the initial particle size distribution diagrams are drawn.(3)Dried mudstone grain samples are exposed to air with constant moisture for 2,3,9,15,24,and 35days.(4)After varying exposures intervals,each sample is subjected to particle size distribution analysis again as in step (2),and the disintegrated particle size distribution dia-grams are plotted again.(5)The disintegration is discussed by comparing the particle size distribution diagrams.Fig.3(a)shows a plot of the particle size distributions of mudstone grains during disintegration tests and Fig.3(b)shows the uniformity coef ﬁcients.Fig.3(a)clearly shows that mudstone grain disintegration in-creases with the exposure time.Disintegration is more obvious in the early phase (ﬁrst 15days),indicating that mudstone grains disintegrate rapidly initially.After 15days,the disintegration speed decreases and most grains (diameter:>60mm)are almost dis-integrated.For instance,when the median grain diameter (d 50)decreases to 50,25,20,6,4,3.1,and 2.0mm,the disintegration times increase to 2,3,9,15,24,and 35days,respectively.Fig.3(b)shows the increase in the uniformity coef ﬁcient of mudstone grain with the disintegration time in the early phase and the decrease in the same with the disintegration time in the later phase (after the ﬁrst 15days),which also demonstrates that most large grains had already been disintegrated in the early phase.Based on the results,the recommended disintegration time is w 15days for embank-ment construction sites.2.2.Specimen preparationThe properties of commercially available polyvinyl chloride (PVC)geogrids with longitudinal and transverse ribs are summa-rized in Table 2.Field weathered mudstone residual soil is a yellow-cyan coarse-grained soil with irregular oblong-,pyramid-,or chip-shaped grains.This weathered mudstone coarse-grained soil has a me-dian grain size diameter (d 50)of 55mm and a uniformity coef ﬁcient (C u )of 4.0.The maximum void ratio (e max )is 0.85,and the mini-mum void ratio (e min )is 0.46.The ﬁeld void ratio (e )is 0.72,and the relative density (D r )is 0.31,which indicates the relatively loose condition in ﬁeld.The basic physical parameters of weathered mudstone coarse-grained soil are listed in Table 3,and its grain size distribution is shown in Fig.4.Not all coarse grains in ﬁeld can be directly accepted for labo-ratory testing,and the coarse grains ’size effects are obvious (Zekkosa et al.,2008,2012).Several studies have recommended that the largest grain diameter be not greater than 1/6or even 1/10of the specimen diameter for minimizing scale effects (Varadaraja et al.,2003).In this study,the diameter of the largest grain in the sample was not greater than 1/5of the specimen diameter,and the size effects were acceptable (Guo,1999).The specimen dimensions are as follows:diameter ¼300mm,height ¼600mm,and a common height-to-diameter ratio of 2according to ASTM D3999-91.The ﬁeld grain size distribution was highly imitated using the weight equivalence method (Guo.1999)in this study,and the large-scale triaxial testing samples were prepared by ﬁltering the ﬁeld mudstone coarse-grained soil with a 60-mm aperturediameterFig. 3.Particle size distribution and uniformity coef ﬁcients during disintegration testing.Table 2Physical dimensions and tensile parameters of polyvinyl chloride geogrids.Aperture length (mm)Aperture width (mm)Longitudinal rib width (mm)Tranverse rib Width (mm)Thickness of rib (mm)Ultimate tensile strength (kN/m)2%Strain tensile strength (kN/m)Longitudinal Tranverse Longitudinal Tranverse 40.038.05.04.03.081.272.568.368.9X.Chen et al./Geotextiles and Geomembranes 42(2014)312e 328316sieve.Theﬁeld and experimental grain size distribution diagrams for weathered mudstone coarse-grained soils are plotted in Fig.4. Although there is a little difference between theﬁeld grain size distribution and the experimental grain size distribution,the de-viation of the testing results and the coarse grain size effects could be acceptable(Guo,1999;Varadaraja et al.,2003).The dry tamping method,moist tamping method,dry pluviation method,and wet pluviation method are commonly used for large-scale reconstituted specimen preparation(Wichtmann et al.,2005). Among these,the moist tamping method allows for specimen preparation with arbitrary relative density and achieves sufﬁcient homogeneity through the application of different compaction ef-forts on each layer,thus compacting each layer to the same density. Considering the characteristics of these methods,the moist tamp-ing method was selected for large-scale triaxial soil specimen preparation in this study.All samples were thoroughly mixed with optimum moisture content(12%).They were then sitting in a curing tank with the same moisture content for at least24h before specimen making.The mudstone coarse-grained soil samples were poured layer-by-layer(ﬁve layers)into cylindrical steel moulds. Then,the mudstone coarse-grained soil samples were compacted such that all layers had the same speciﬁc density,and the surfaces of each layer were scratched to ensure better bonding with the next layer.The degree of compaction of each layer was95%,and poly-vinyl chloride geogrids were embedded at suitable heights(sepa-ration of30,20,and15cm between layers,respectively).To examine the effects of geogrid reinforcement,specimens with no geogrids as well as one,two,and three layers of geogrids were prepared in this study.The specimen symbols and testing programs used in these large-scale triaxial tests are summarized in Table4.2.3.Experimental procedureCU and CD triaxial tests were conducted using a large-scale triaxial setup based on the BS1377-8standards(1990,Methods of test for soils for civil engineering purposes Shear strength tests). Most of the tests performed are CU tests,with CD tests only being performed for volumetric strain analysis.All specimens were tested under fully saturated conditions.A combination of the back pres-sure saturation method and the CO2ﬂushing saturation method was used for achieving sufﬁcient degrees of saturation.The Skempton pore pressure parameter(B¼D u/Ds3)was used as an indicator of the degree of saturation as the specimen was saturated. It is widely accepted that when B>0.95in testing,the degree of saturation,S,reaches100%(Karg and Haegeman,2009).However,it is very difﬁcult to achieve B!0.95for the laboratory testing of large-scale coarse-grained soil specimens,especially for the clayey soils.In practice,it is presumed that B>0.85indicates a degree of saturation of at least99.5%(Thooft,1991).In the mudstone geogrid-reinforced coarse-grained soil triaxial tests,the B values of all samples were0.90e0.95,indicating that all the samples were sufﬁciently saturated.When the saturation procedure was completed,the isotropic consolidation procedure was applied with the specimen drainage valves left open;the time required for full consolidation was8e12h during testing.After consolidation,a shear deviator stress(s1e s3)was applied to the specimens,and the resulting shear behaviours were observed.In the shear test,the shearing speeds were controlled by the axial deformation rates of 0.01cm/min(CU)and0.005cm/min(CD).The shear test was terminated when the axial strain reached15%or the stress reached the critical condition(Torav,1985;Zhu,2003).During testing,the shear stress,shear strain,pore water pressure,and specimen failure shapes were investigated.The obtained critical stress states are summarized in Table5.3.Tests results and analysis3.1.Shear behaviourThe failure shapes of specimens are shown in pared with the original shape,three main types of failure shapes are typically observed:shear banding,middle bulging,and top bulging. These failure shapes are likely related to the embedded geogrid layers.For example,shear banding failure is more likely to occur in non-reinforced specimens;middle bulging failure,in specimens reinforced with two geogrid layers;and top bulging failure,in specimens reinforced with three geogrid layers.The middle and top bulging failure specimens show a clear bulge at a height of0.5e 0.7H and0.7e0.8H,respectively.The experimental principal stresses,principal strains,and pore water pressures during shear testing were focused on,and all of them were automatically recorded by the triaxial setup.Under different conﬁning pressures,the critical deviatoric stresses,axial strains,and shear e induced pore water pressures of mudstone geogrid-reinforced coarse-grained soil specimens are plotted in Fig.6.In determining the specimens’shear behaviour,the effects of geogrids are as evident as those of the conﬁning pressure.As shown in Fig.6,the S1group specimens exhibit a strain-softening trendTable3Basic physical parameters of weathered mudstone coarse-grained soil.Density/g/cm3Relative density/Dr Natural water content/%Optimum water content/%Fine particles liquid limit/%Fine particles plastic limit/%1.930.3117123215.9C.B.R.value at different compact degree MLR(Sulphate invading)/%Void ratio Saturation degree90%93%95%n(%)S r(%)39.645.547.0 1.57267.5Note:C.B.R.is the California Bearing Ratio Test.MLR is the Mass Loss Rate when sulphate corrosioninvade.Fig.4.Particle size distribution of weathered mudstone coarse-grained soil.X.Chen et al./Geotextiles and Geomembranes42(2014)312e328317under low con ﬁning pressures;however,the geogrid-reinforced specimens tend to undergo strain hardening,especially the S3group specimens.These experimental results show that the geogrid likely leads to strain hardening under shearing,and the magnitude of this strain hardening is possibly related to the extensile force applied to the geogrid.However,the geogrid ’s extensile force takes obvious effect until its strains accumulate to a suitable level.During shearing,the effect of the geogrid is not obvious when the total axial strain is less than 1%(εa <1%),and the shear curves are very close (as shown in Fig.6).The effect of geogrids becomes more obvious when the axial strain is larger than 1%(εa >1%).Under a con ﬁning pressure of 50kPa,when the shear strain reaches 5%,the shear force (s 1e s 3)reaches 153,195.3,214.4,and 233.1kPa,respectively,for the unreinforced specimen and specimens rein-forced with one,two,and three geogrid layers.The extensile force of the geogrid gradually contributes to the improvement of the reinforced specimens ’shear strength with an increase in the shear strain.Shear deformation leads to strain hardening as the con ﬁning pressure and number of reinforcing geogrid layers increase.Based on experimental data,εa vs.(s 1Às 3)/εa curves of the weathered mudstone coarse-grained soil specimens are plotted in Fig.7.The values of (s 1Às 3)/εa decrease with an increase in the axial strain,and the number of geogrid layers in ﬂuences the curves ’slopes as well as the con ﬁning pressure.The εa vs.(s 1Às 3)/εa curves for the unreinforced samples are linear,as shown in Fig.7(a),which suggests that these specimens ’shear behaviours potentially tend toward shear dilatancy and strain softening.With the presence of geogrid layers,εa vs.(s 1Às 3)/εa curves of the reinforced samples become nonlinear (Fig.7(c e d)).The nonlinear shapes of the curves indicate that the shear behaviour tends toward shear contractancy or strain hardening because of geogrid reinforcement.It is commonly accepted that the volume deformation of a specimen equals the volume of water drained from the specimen in the CD triaxial tests.Therefore,the volume deformation of spec-imen can be determined by measuring the volume of drained wa-ter.During the large-scale consolidated drained triaxial tests,the volume of drained water was measured.Therefore,the specimen ’s volume deformation was obtained indirectly,and the relationshipsTable 4Programs for mudstone coarse-grained soil in large-scale triaxial tests.Test methodSpecimen symbol Embedded geogridsDry density (g/cm 3)Con ﬁning pressure s 3/kPa (CU and CD)method outlined in Standard ASTM D3999-91S1group No geogrid1.8950,100,150,200S2group One layer of geogrid (30cm per layer)50,100,150,200S3group Two layers of geogrid (20cm per layer)50,100,150,200S4groupThree layers of geogrid (15cm per layer)50,100,150,200Table 5Critical stress conditions and residual pore water pressure during axial CU testing.Specimen group Load step s 3(kPa)s 1(kPa)s 1e s 3(kPa)Max pore water pressure u w (kPa)Failure shape description S1150156.2106.238.5Shear band 2100251.5151.539.5Shear band 3150309.4159.459.1Shear band 4200399.2199.263.8Middle bulge S2150186.4136.441.8Middle bulge 2100287.6187.642.3Shear band 3150381.0231.070.2Middle bulge 4200447.2247.273.5Middle bulge S3150231.0181.048.6Middle bulge 2100322.5222.559.2Middle bulge 3150411.5261.578.7Top bulge 4200478.3278.386.9eS4150261.5211.553.5Top bulge 2100360.5260.569.3Top bulge 3150434.1284.192.0Total bulge 4200500.0300.0105.2TopbulgeFig.5.Sketch of specimen failure shapes.X.Chen et al./Geotextiles and Geomembranes 42(2014)312e 328318。

香港机场航图

General InfoHong Kong, HKGN 22?18.5' E113?54.9' Mag Var: 1.9訖Elevation: 28'Public, IFR, Control Tower, Low Level Wind Shear Alert System, Customs Fuel: Jet A-1Repairs: Major Airframe, Major EngineTime Zone Info: GMT+8:00 no DSTRunway InfoRunway 07L-25R 12467' x 197' asphaltRunway 07R-25L 12467' x 197' asphaltRunway 07L (73.0衽) TDZE 22'Lights: Edge, ALS, Centerline, TDZDisplaced Threshold Distance 568'Runway 07R (73.0衽) TDZE 27'Lights: Edge, ALS, Centerline, TDZDisplaced Threshold Distance 525'Runway 25L (253.0衽) TDZE 27'Lights: Edge, ALS, Centerline, TDZRunway 25R (253.0衽) TDZE 22'Lights: Edge, ALS, Centerline, TDZDisplaced Threshold Distance 571'Communications InfoATIS 128.2 Arrival ServiceATIS 127.05 Departure ServiceHong Kong Tower South Tower 118.4Hong Kong Tower North Tower 118.7 SecondaryHong Kong Tower North Tower 118.2Hong Kong Ground South Ground Control 122.55Hong Kong Ground North Ground Control 121.6Hong Kong Delivery Clearance Delivery 129.9Hong Kong Delivery Clearance Delivery 124.65 SecondaryHong Kong Precision Approach Control 133.7Hong Kong Director Approach Control 119.5Hong Kong Director Approach Control 119.35Hong Kong Director Approach Control 120.1 SecondaryHong Kong Approach Control 119.1Hong Kong Departure Control 122.0Hong Kong Departure Control 124.05 SecondaryHong Kong Departure Control 123.8Hong Kong Departure Radar 122.0Zone Control 120.6Notebook Info1.1.ATISD-ATIS Arrival128.2D-ATIS Departure127.051.2.NOISE ABATEMENT PROCEDURES1.2.1NOISE MITIGATING MEASURESThe following procedures are implemented daily to reduce ACFT noise levels, whenoperating conditions permit. Noise mitigating procedures are not applicable tocalibration flights.1.2.1.1.PREFERENTIAL USE OF RWYS 07L/RAs a noise mitigating measure between 0001-0700LT, RWYs 07L/R will be nominated as the RWY direction-in-use whenever the tailwind component (including gusts) is10 KT or less when the RWY is dry, or 5 KT or less when the RWY is not dry. Duringthis period RWYs 25L/R may be used if operationally required, e.g. unserviceability of navigation aids, adverse weather conditions, ACFT performance, trafficsituations etc.1.2.2.RUN-UP TESTSEngine run-ups are subject to the following conditions:-An engine ground run is defined as any engine start-up not associated with aplanned ACFT departure.-Engine ground runs at ground idle power of not more than two engines at a time and for a duration not exceeding ten minutes may be carried out on the Passenger Apron or Cargo Apron.-Engine runs above ground idle power shall be carried out in the run-up facility andengine ground runs at idle power for a duration in excess of ten minutes shall onlybe carried out in approved locations.-All engine ground runs must be fully supervised by ground staff.-Maintenance or test running of jet engines not mounted on an ACFT is prohibitedunless performed in a test cell of adequate design.ENGINE GROUND RUN PROCEDURESInitial request for a ground engine run should be made to the APT Authority ApronControl Centre (Tel No: 2910 1112). The airline, ACFT maintenance agent engineer or mechanic in charge of the engine test is responsible for ensuring that all safetyprecautions against injury to persons or damage to properties, aircraft, vehicles and equipment in the vicinity are adopted.When ready to conduct the engine run, the pilot or authorized engineer shall obtain start-up clearance from Apron Control on 121.77 and a listening watch shall bemaintained on the frequency throughout the engine run. The ACFT anti-collisionbeacons must be activated for the entire duration of the ground engine run and Apron Control should be advised on its completion. The ground crew in charge mustmaintain communication with cockpit personnel and be able to stop the engine runimmediately if directed.1.3.LOW VISIBILITY PROCEDURES (LVP)1.3.1.GENERALLow Visibility Procedures are established for operations in a visibility of less than RVR 550m or a cloudbase of less than 200ft.ACFT operators must obtain approval from the Director-General of Civil Aviationprior to conducting any low visibility operations.Special procedures and safeguards will be applied during CAT II/III operations toprotect ACFT operating in low visibility and to avoid interference to the ILS signals.Pilots shall be informed when:-meteorological reports preclude ILS CAT I operations;-Low Visibility Procedures are in operation;-there is any unserviceability in a promulgated facility so that they may amendtheir minima.Pilots who wish to carry out an ILS CAT II/III approach shall inform ApproachControl on initial contact. Pilots may carry out a practice ILS CAT II/III approach at any time, but the full safeguarding procedures will not be applied and pilots should anticipate the possibility of ILS signal interference.1.3.2.ARRIVALACFT shall only vacate:-RWY 07L via TWYs A9 or A12;-RWY 07R via TWYs J7, J10, K6 or K7;-RWY 25L via TWYs H1, J3, K1 or K2;-RWY 25R via TWYs A1, A4 or A6.All RWY exits have TWY centre-line lead-off lights that are colour coded (green/yellow) to indicate that portion of the TWY that is within the ILS sensitive area.Pilots are to delay the 'RWY vacated' call until the ACFT has completely vacated the ILS sensitive area and passed the end of the colour coded TWY centre-line lights. 1.3.3.DEPARTUREACFT shall normally only enter:-RWY 07L via TWYs A1 or A2;-RWY 07R via TWYs H1, J1 or K1;-RWY 25L via TWYs J9, J10 or K7;-RWY 25R via TWYs A11 or A12.Holding positions on TWYs A1, A2, H1, J1, J9 and J10 are CAT I/II holding positions.Separate CAT II holding positions are provided on TWYs K1, K7 and K.Holding positions on TWYs A11 and A12 are CAT I/II/III holding positions.1.4.SURFACE MOVEMENT GUIDANCE AND CONTROL SYSTEMAPT is equipped with an Advanced Surface Movement Guidance and Control System (A-SMGCS) operating on a trial basis. The system is a Multistatic DependentSurveillance (MDS) multilateration system that utilises Mode S transponderstransmissions.To facilitate a full evaluation of the trial, pilots of ACFT equipped with 'weight-on-wheel' switch must ensure that the transponder is operating (select AUTO or XPNDR, do not switch to STAND-BY or OFF) and the assigned Mode A code is selected inaccordance with the following:-for a departing flight, from the request for push-back or taxi, whichever is earlier, -for an arriving flight, continuously until the ACFT is fully parked at the stand.For ACFT NOT equipped with 'weight-on-wheel' switch, follow existing transponder operating procedures.For ACFT that are capable of reporting ACFT Identification, (i.e. callsigns used inflight), the ACFT Identification should also be entered via FMS or Control Panel.1.5.TAXI PROCEDURESTaxi with extreme CAUTION and MIM engines power only.1.6.PARKING INFORMATION1.6.1.GENERALAll parking stands on the passenger apron are equipped with an automated docking guidance system for the centerline parking position.1.6.2.FRONTAL PARKING BAYSFrontal parking bays are those bays which are served by airbridges with directaccess to the passenger terminal building. All frontal parking bays can accommodate all current wide-body types of ACFT and have continuous yellow nosewheel guidance lines to indicate the correct parking centerline.Some frontal parking bays can also accommodate narrow-body types of ACFT at aseparate parking bay location displaced 30'/9m to the RIGHT of the wide-bodycenterline and indicated by a dashed yellow guidance line. The narrow-body parking bay is referred to by a "R" suffix, e.g. S23R. The following parking bays canaccommodate narrow-body types of ACFT:-South Apron E1R, E2R, E3R, S23R, S25R, S27R, S29R, S31R, S33R, S35R, S41R,S43R, S45R, S47R and S49R.-North Apron E16R, E17R, N22R, N24R, N26R, N28R, N30R, N32R, N34R, N60R,N62R, N64R, N66R, N68R and N70R.-West Apron W40R, W42R, W44R, W46R, W48R, W61R, W63R, W65R, W67R,W69R and W71R.1.6.3.REMOTE PARKING BAYS1.6.3.1.NORTH/SOUTH APRONAll remote parking bays on the North and South aprons have continuous yellownosewheel guidance lines.1.6.3.2.WEST APRONThe remote parking bays on the West apron are configured to accommodate up to5 wide-body type ACFT or up to 7 narrow-body type ACFT, or a combination of wideand narrow-body type ACFT.The wide-body parking locations have continuous yellow nosewheel guidance lines to indicate the correct parking centerline.The narrow-body parking locations are displaced to the LEFT and the RIGHT of thewide-body centerline and are indicated by dashed yellow nosewheel guidance lines.These narrow-body parking bays are referred to by a "L" or "R" suffix, e.g. W121L or W123R.1.7.OTHER INFORMATION1.7.1.GENERALBirds in vicinity of APT.1.7.2.LOCAL WIND EFFECTS1.7.2.1.GENERAL WARNINGDue to the proximity of the hilly terrain of Lantau Island to the South and East ofAPT, significant low-level windshear and moderate to severe turbulence can beexpected along the approaches to and departures from both RWYs when winds blowoff these hills, i.e. from East through Southwest at about 15 KT or more. As the hills to the North are further away, they play a less significant role, but none the less can create local wind effects when strong winds blow off these hills , i.e. fromNorthwest through Northeast, at about 20 KT or more.The terrain induced wind disturbances from nearby hills can be very small scale,sporadic and transient in nature. Whilst these wind disturbances may be small inphysical dimension and correspond to only several seconds of flight time, significant headwind changes (i.e. RWY orientated wind speed losses and/or gains being 15 KT or greater), can be expected as the ACFT flies through them. The sporadic andtransient nature of the terrain-induced wind disturbances results in some ACFTexperiencing windshear and/or turbulence, whilst others do not, even though thebroad meteorological conditions are the same. Successive ACFT which experiencewindshear and/or turbulence may also encounter a different sequence of events.Surface winds at the APT are generally not good indicators of the wind that may be experienced during the final phase of the approach. Winds at approximately 2000 ft may be a better representation of the prevailing wind conditions in the region.Generally, mean wind speed should decease towards lower altitudes but isolatedstrong gusts may be expected. Wind direction would also change with altitude due to blocking of the general wind flow by nearby hills or in the presence of low-leveltemperature inversion which occurs mostly in the cool season (about half of the time or more from November to April). It is possible for the magnitude of windshear and turbulence to increase towards final approach, resulting in deteriorating rather than improving conditions prior to touchdown.1.7.2.2.EASTERLY THROUGH SOUTHWESTERLY WINDSWhen prevailing winds are from the East through Southwest and with a speed inexcess of 15 KT, significant windshear and moderate turbulence can be expected on the approaches to or on departure from both RWYs. Larger magnitude of windshearand turbulence is possible when the wind speed is in excess of 30 KT. Because of the closeness to the hills of Lantau, the windshear and turbulence are more significantover the southern RWY (RWY 07R/25L).Low-level windshear and turbulence are expected to be more significant when thewind is from the direction 130^ - 210^ , especially in the presence of low-leveltemperature inversion or when the wind speed is more than 30 KT.1.7.2.3.NORTHWESTERLY THROUGH NORTHEASTERLY WINDSSignificant low-level windshear and moderate turbulence can be expected when wind speeds exceed 20 KT, especially for approaches to RWY 25L/R and along thedeparture and missed approach corridors from RWY 07L/R as these approach/departure corridors are closer to the hills to the North as compared with approaches to RWY 07L/R. Larger magnitude of windshear and turbulence over these approachand departure corridors is possible if the wind speed exceeds 30 KT, especially in the vicinity of "LOTUS".1.7.ND-SEA BREEZELand-sea breeze is not a strong wind phenomena but it can create a complex windfield in the vicinity of the APT and it can cause a significant change in winddirection within a distance of a few kilometers along the approach/departure areas.If the sea breeze opposes the prevailing wind flow it can result in significantwindshear even if fine weather conditions.1.7.2.5.LOW-LEVEL JET IN COOL SEASONDuring a surge of the winter monsoon, strong low-level jets of northeasterly windwith speeds up to 50 KT occasionally affect the APT. Under such circumstancessignificant windshear along the departure corridors of RWY 07L/R can be expected. 1.7.2.6.LOW-LEVEL WIND EFFECTSPilots should be aware of building-induced turbulence and windshear effects whenlanding at following conditions:- RWY 07R at strong northwesterly/northerly winds with a background speed ofabout 15 KT or more- RWY 25L at strong northwesterly/northerly winds- RWY 25R at strong southwesterly/southerly/southeasterly winds1.7.3.WINDSHEAR AND TURBULENCE WARNING SYSTEM (WTWS)1.7.3.1.MICROBURST/WINDSHEAR ALERTSThe Microburst or Windshear alert passed by ATC includes the type of alert (i.e.microburst or windshear), the magnitude of the RWY orientated wind speeddifference and the location (final approach or departure area as appropriate).When more than one occurence of wind shear is detected for a particular RWYcorridor, WTWS provided a consolidated Microburst or Wind Shear Alert for thatparticular RWY corridor based on a priority system wich takes into consideration the severity of the alerts and the confidence level of the different data sources whichgenerate the alerts.E.g. If a microburst with an intensity of minus 30 KT and a wind shear with anintensity of plus 15 KT are detected, only a Microburst Alert will be issued.Gain and loss events can co-exist within the same RWY corridor, particularly forterrain-induced wind shear. The WTWS is designed to assign a higher priority to aWind Shear Alert of wind loss compared to a Wind Shear Alert of wind gain. If the former is issued pilots are reminded that they may still encounter wind gain events.1.7.3.2.TURBULENCE ALERTSThe Turbulence Alert passed by ATC includes the intensity and type of alert (i.e.moderate or severe turbulence), and the location (final approach or departure areaas appropriate). The alert intensity (i.e. moderate or severe) follows ICAO'sstandard definition for reporting of turbulence .1.7.3.3.MICROBURST/WINDSHEAR ALERT COMBINED WITH TURBULENCE ALERTWhen a "Microburst Alert" or a "Windshear Alert" is given for a particular RWYand turbulence is also detected for that particular RWY, a "Turbulence Alert" willbe passed by ATC together with the "Microburst Alert" or "Windshear Alert". 1.7.4.LIGHTNING WARNING SYSTEMWhen the system predicts a strong probability of a lightning strike on the APTplatform, APT authority will issue a Red Lightning Warning. When airlines andhandling agents receive a Red Lightning Warning through SITA they should adviseinbound flights of the warning.If the period of the Red Lightning Warning is forecast to be prolonged, a messagewill be included on the ATIS broadcast advising of delays to parking and/or push-back.Because ground crew operations are suspended the wheels will not be chocked. APU should remain in operation. In the event of an inoperative APU, pilot shall keep one starboard engine running. ACFT unable to comply with this procedure should notifyGround Movement Control on initial contact.Ground crews will not commence a push-back when a Red Lightning Warning is inforce.1.8.LOW LEVEL TCAS ALERTS WITH HONG KONG CONTROL ZONEIFR flights sometimes experience TCAS alerts, these may be caused by transponder-equipped VFR or Special VFR flights operating on low-level routes in the vicinity of APT.Even though separation is provided, ATC will, under such circumstances, issuetraffic information to the ACFT concerned whenever practicable so that pilots will be aware of the possible TCAS alerts.2. ARRIVAL2.1.NOISE ABATEMENT PROCEDURES2.1.1NOISE MITIGATING MEASURESThe following procedures are implemented daily to reduce ACFT noise levels, when operating conditions permit. Noise mitigating procedures are not applicable tocalibration flights.2.1.1.1.CONTINUOUS DESCENT APPROACH (CDA) FOR RWYS 25L/RAs a noise mitigating measure between 2301-0700LT arrivals to RWYs 25L/R mayexpect an ILS/DME approach with a CDA procedure subject to the prevailing traffic situation.-ACFT on the CDA procedure are expected to achieve a continuous descent profileapproximating a 3^ vertical profile from 8000' to intercept the GS at or above4500'.During a CDA pilots should maintain a low thrust setting and should not haverecourse to level flight.-ACFT will be given radar vectors from about 27 NM from touchdown (12 NM toFAF), to intercept the LLZ outside of the FAF (LOTUS D15 IFL - RWY 25L, RIVER D15 ITFR - RWY 25R). The estimated track miles to touchdown will be passed withdescent clearance and further distance information may be given as required.-The recommended speed for the CDA intermediate approach segment is 210-225 KT, this should permit a relatively clean configuration for as long as practicable. Thepublished speed restrictions for the final approach segment are applicable for theCDA procedure, 180 KT at FAF and between 150-160 KT at 4 NM from touchdown.-If ACFT cannot comply with the CDA procedures or speed limitations, the pilotshould advise ATC in good time so that alternative arrangements can be made.2.2.CAT II/III OPERATIONSRWYs 07L, 07R and 25L approved for CAT II, RWY 25R for CAT II/III operations,special aircrew and ACFT certification required.2.3.RWY OPERATIONS2.3.1.RWY UTILISATIONVacate RWY as quickly as practicable.To facilitate minimum RWY occupancy time, each RWY has multiple rapid exit TWYs.Vacate via the first available rapid exit TWY commensurate with operationalconditions, or as instructed.ACFT vacating the RWY should not stop on the exit TWY until the entire ACFT haspassed the RWY holding point.2.3.2.REDUCED RWY SEPARATION MINIMUMS (RRSM)RRSM may be applied between a departing ACFT and a succeeding landing ACFT orbetween two successive landing ACFT on the same RWY provided the followingconditions exist:-visibility of at least 5 km;-ceiling in the departure/missed approach area 3000' or more;-during daylight hours from 30 minutes after local sunrise to 30 minutes before local sunset;-the second ACFT will be able to see the first ACFT clearly and continuously untilthe first is clear of the RWY;-no unfavorable surface wind conditions (including significant tailwind/turbulenceor windshear, etc);-braking action not adversely affected by water or other contaminants (i.e. RRSMwill be suspended whenever the RWY is wet or there is pilot report of poor braking action).Pilots shall inform ATC in good time in the event that ACFT may not vacate the RWY expeditiously due technical or OPR reason.When RRSM is applied, the successive landing ACFT may be given clearance to landbefore the first ACFT has cleared the RWY-in-use after landing or crossed the RWYend on departure provided there is reasonable assurance that the followingseparation distances will exist when the landing ACFT crosses the THR:RWY 07L/25R-Landing following departure:The departing ACFT is/will be airborne and has passed a point at least 2400m fromTHR (ABEAM TWY A8 for RWY 07L or TWY A5 for RWY 25R).-Landing following landing:The preceding ACFT has landed and has passed a point at least 2400m from THR(ABEAM TWY A8 for RWY 07L or TWY A5 for RWY 25R), is in motion and willvacate the RWY without backtracking.RWY 07R/25L-Landing following departure:The departing ACFT is/will be airborne and has passed a point at least 2900m fromTHR (ABEAM TWY K6 for RWY 07R or TWY K2 for RWY 25L).-Landing following landing:The preceding ACFT has landed and has passed a point at least 2900m from THR(ABEAM TWY K6 for RWY 07R or TWY K2 for RWY 25L), is in motion and will vacate the RWY without backtracking.ATC will provide warning to the second ACFT when issuing the landing clearance in line with ICAO standard phraseology, eg:-(Callsign....), preceding B737 landing about to vacate the RWY, surface wind 090 degrees/ 11 KT, cleared to land.-(Callsign....), departing A320 ahead about to rotate, surface wind 230 degrees/ 6 KT, cleared to land.Pilots must notify ATC in advance if they anticipate not being able to comply with any of the above requirements.2.4.OTHER INFORMATION 2.4.1.DISTANCE FROM TOUCHDOWN INFO In the event of airborne DME receiver failure or ground equipment failure,equivalent DME ranges will be provided by PRM controller for ILS CAT I approach at Final Approach Point and Outer Marker fix on frequency 133.7 MHz, as outlined in the following table:In the event of airborne DME receiver failure, pilots must advise ATC prior to commencing the approach.3.1.START-UP & PUSH-BACK PROCEDURES All ACFT other than helicopters and locally light ACFT shall obtain an ATC clearanceprior to engine start. Pilots are to inform HONG KONG Ground/Delivery, asappropriate, of callsign, parking stand number/location, identifier of the latestATIS received unless it has been included in the RCD (request for departure clearance down link) message via datalink, proposed flight level if it is different from thefiled flight plan and when applicable, special requirements (e.g. request for another departure RWY or inability to comply with SID climb profile).Additionally, departures for destinations in China routeing via BEKOL (A461) shall contact Hong Kong Delivery 15 minutes before estimated off-block time (EOBT) to obtain advance notification of any flow control restriction that may affect the flight.A 2-way Pre-Departure Clearance (PDC) data link service is available to approved operators from HONG KONG Delivery between 0730-0030LT daily. Pilots should send a RCD to ATC not more than 20min prior to EOBT. If the CLD message is not received within 5 min or there is any problem with date link exchange, pilot shall inform HONG KONG Delivery.Pilots not participating in the PDC service shall contact HONG KONG Deliverybetween 0730-0030LT. All pilots shall contact HONG KONG Ground (South) between 0030-0730LT 5 minutes prior to start to put their ATC clearance on request. Upon receipt of the ATC clearance the pilot shall read back the following information:-Callsign, - Destination, - Route, - SID, - SSR code.3. DEPARTUREPilots shall comply with instructions issued by HONG KONG Delivery regarding when to contact the relevant HONG KONG Ground frequency.Once an ATC clearance has been received, unless there is a specific time restriction included in the clearance, any delay in being ready to push-back, start engines ortaxi may result in the clearance being cancelled.Pilots shall contact HONG KONG Ground (South) except when notified it is sectorised, in which case pilots shall contact:-HONG KONG Ground (North) for North and West Aprons.-HONG KONG Ground (South) for South, Cargo and Business Aviation Aprons.Prior to requesting for push-back or taxi from a parking stand, pilots of ACFT equipped with a "weight-on-wheel" switch must ensure the transponder is operating (on "AUTO" or "XPNDR", and not "STDBY" or "OFF") and the assigned Mode A code is selected. ACFT with Mode S transponder capable of reporting ACFT Identification should have its identification in the ICAO flight plan format entered via FMS or Control Panel.The majority of parking bays have two standard push-back procedures, push-back BLUE and push-back RED. The normal push-back procedure is to the taxilane ABEAM the adjacent parking bay, but where this would result in the ACFT entering a critical area the push-back is extended to a Tug Stop Point clear of the critical area.Stands E2, E17, N24, N30, N60, N142, N143, S25, S31, S43, S102 thru S104, S108,S110 and W65 have a push-back/tow-forward procedure, push-back GREEN.If this push-back procedure is not acceptable due to operational restrictions, pilot should inform ATC immediately and alternative push-back arrangements will be given.ACFT making a push-back GREEN should be ready for taxi as soon as the push-back and tow-forward procedure and engine start process has been completed.Under certain traffic conditions it may be necessary for Hong Kong Ground to issue non-standard push-back instructions to expedite to flow of traffic. Pilots will be issued a "non-standard push-back" to a defined location and direction.Pilots shall ensure that the push-back colour code or non-standard push-back instructions issued by HONG KONG Ground are accurately relayed to their ground crew before push-back or engine start commences.There is a restriction to the starting of engines for ACFT in parking bays S103, S108 and W123. If ACFT in these bays are required to push-back through 180^, only one engine shall be started during the push-back, other engines shall only be started when the push-back manoeuvre has been completed.When known conditions exist which necessitate that engine start-up is carried out in the parking bay prior to the commencement of push-back, or greater than idle engine thrust will be required during engine start (e.g. cross-bleed start procedure), the pilot shall advise HONG KONG Ground of the fact when engine start or push-back clearance is requested.Whilst push-back procedure is being conducted, it is essential for safety reasonsthat communication contact is maintained between pilot and ground engineer in charge. ATC clearance will not normally be issued to ACFT whilst being pushed back, unless the pilot so requests.To avoid delay to other traffic using the apron ACFT should be ready to taxi as soon as the push-back manoeuvre and engine start procedure are completed. The standard push-back for stands N68 and N70 is into TWY B, therefore to avoid delays to other traffic it is essential that the ACFT should be ready to taxi as soon as the push-back manoeuvre is complete. If ACFT are unable to comply with this procedure, pilotsshall immediately inform HONG KONG Ground in order that alternative taxi instructions may be issued to other traffic.Pilots are reminded that they should always use minimum power when starting engines or manoeuvring within the apron area. It is especially important when commencing to taxi that break-away thrust is kept to an absolute minimum and then reduced to idle thrust as soon as practicable.。

DIN EN 74 2脚手架和支承架用连接件、定位销和底板.第2部分专用连接件.要求和试验程序

DEUTSCHE NORM January 2009DIN EN 74-2 D ICS 91.220Couplers, spigot pins and baseplates for use in falsework andscaffolds -Part 2: Special couplers -Requirements and test proceduresEnglish version of DIN EN 74-2:2009-01Kupplungen, Zentrierbolzen und Fußplatten für Arbeitsgerüste und Traggerüste -Teil 2: Spezialkupplungen -Anforderungen und PrüfverfahrenEnglische Fassung DIN EN 74-2:2009-01Document comprises 43 pages©No part of this standard may be reproduced without prior permission ofEnglish price group 16 !$U:Ö"DIN Deutsches Institut für Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;1502397D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01National forewordThis standard has been prepar ed by Technical Committee CEN/TC 53 “Temporary works equipment” (Secretariat: DIN, Germany).The responsible German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Technical Committee NA 005-11-05 AA Arbeits- und Schutzgerüste und Gerüstbauteile.2D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EUROPEAN STANDARD EN 74-2NORME EUROPÉENNE EUROPÄISCHE NORMSeptember 2008ICS 91.220English VersionCouplers, spigot pins and baseplates for use in falsework and scaffolds - Part 2: Special couplers - Requirements and test proceduresRaccords, goujons d'assemblage et semelles pourKupplungen, Zentrierbolzen und Fußplatten fürétaiements et échafaudages - Partie 2: Raccords spéciaux -Arbeitsgerüste und Traggerüste - Spezialkupplungen -Exigences et modes opératoires d'essaiTeil 2: Anforderungen und PrüfverfahrenThis European Standard was approved by CEN on 9 August 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels© 2008 CEN All rights of exploitation in any form and by any means reserved worldwideRef. No. EN 74-2:2008: Efor CEN national Members.D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01 EN 74-2:2008 (E)ContentsPageForeword .............................................................................................................................................................. 3 Introduction .......................................................................................................................................................... 4 1 Scope ...................................................................................................................................................... 5 2 Normative references .............................................................................................................................5 3 Terms and definitions ............................................................................................................................6 4 Symbols .................................................................................................................................................. 8 5 Types and classification of special couplers .......................................................................................9 6 Transmissible internal forces, moments and related stiffnesses ..................................................... 10 6.1 General ..................................................................................................................................................10 6.2 Half coupler ...........................................................................................................................................11 6.3 Sleeve coupler with shear studs (SS) .................................................................................................12 6.4 Reduction coupler ................................................................................................................................12 7 Reference tubes/bar for coupler tests ................................................................................................14 8 General requirements ..........................................................................................................................15 8.1 Materials ................................................................................................................................................15 8.2 Design ...................................................................................................................................................15 8.3 Manufacturer’s drawings .....................................................................................................................17 8.4 Production control ...............................................................................................................................17 9 Tests methods and evaluation of results ...........................................................................................17 9.1 General ..................................................................................................................................................17 9.2 Half Couplers ........................................................................................................................................18 9.3 Sleeve couplers with shear studs (SS) ...............................................................................................27 9.4 Reduction couplers ..............................................................................................................................30 10 Designation ...........................................................................................................................................30 11 Marking .................................................................................................................................................31 12 Test report .............................................................................................................................................31 13 Assessment ..........................................................................................................................................31 14Product Manual (31)Annex A (informative) Ongoing production control ........................................................................................ 33 Annex B (informative) Information about the design of temporary works structures (35)B.1 General ..................................................................................................................................................35 B.2 Structural design ..................................................................................................................................35 Bibliography (41)2D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01EN 74-2:2008 (E)ForewordThis document (EN 74-2:2008) has been prepared by Technical Committee CEN/TC 53 “Temporary works equipment”, the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2009, and conflicting national standards shall be withdrawn at the latest by March 2009.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.The couplers specified in this European Standard are intended for use in temporary works for example scaffolds erected in accordance with EN 12811-1 and falsework erected in accordance with EN 12812.In accordance with the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.3D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01 EN 74-2:2008 (E)IntroductionThis is the second of three parts of a standard for couplers. EN 74-1 deals with common types of friction couplers.EN 74-2 deals with other less common types of friction couplers and other couplers. EN 74-3 deals with non-adjustable base plates and loose spigot pins.EN 74-2 is not intended to prevent the development of other types of couplers; for example couplers may be manufactured in aluminium or other materials or be designed for use with steel or aluminium tubes with outside diameters different from those specified in this standard.Whilst such couplers cannot conform to this standard, it is recommended that the principles of this standard are considered in their design and assessment.NOTE In the text of this standard, the term "loose spigot” is used instead of the "spigot pin” in the title.4D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01EN 74-2:2008 (E)1 ScopeEN 74-2 specifies: materials;design requirements;specified values for resistances and stiffnesses which a coupler has to achieve under test; test procedures and assessment;for the following special couplers: screw or wedge half couplers, sleeve couplers with shear studs, right angle reduction couplers and swivel reduction couplers. It gives recommendations for on-going production control.These couplers are for use principally in temporary works. Each coupler is able to be fixed to at least one side to one 48,3 mm diameter steel or aluminium tube. For the other side of reduction couplers, this standard specifies requirements for the diameter and wall thickness of tubes.For testing, screw couplers are tightened with a torque of 50 Nm and wedge couplers are tightened with a 500 g hammer until the jarring blow.Other special half couplers such as half couplers attached by riveting, used mainly for members of prefabricated scaffolds, are outside the scope of this European Standard.NOTE Information on design using special couplers is given in Annex B.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.EN 74-1:2005, Couplers, spigot pins and baseplates for use in falsework and scaffolds — Part 1: Couplers for tubes — Requirements and test proceduresEN 1090-2:2008, Execution of steel structures and aluminium structures — Part 2: Technical requirements for steel structuresEN 12811-1:2003, Temporary works equipment — Part 1: Scaffolds — Performance requirements and general designEN 12811-2:2004, Temporary works equipment — Part 2: Information on materials EN 12811-3:2002, Temporary works equipment — Part 3: Load testingEN ISO 898-1:1999, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs (ISO 898-1:1999)5D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01 EN 74-2:2008 (E)3 Terms and definitionsFor the purposes of this document, the terms and definitions given in EN 12811-1:2003 and EN 74-1:2005 and the following apply.3.1half coupler (HW, HT)coupler which connects a tube of 48,3 mm diameter to another member either by means of welding (HW) or by means of a welded-in threaded element (HT)NOTE See Figures 1 and 2.Keya profile of weldingFigure 1 — Half coupler connected by welding (HW)6D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;DIN EN 74-2:2009-01EN 74-2:2008 (E)Keya profile of welding t thickness of the head of welded-in threaded element 1 welded-in threaded element (bolt, screw, stud, threaded rod)Figure 2 — Half coupler for connection with a welded in threaded element (HT)3.2sleeve coupler with shear studs (SS)coupler for connecting 48,3 mm tubes end to end by means of a pair of shear studs on each side engaging with two predetermined holes in each tubeNOTESee Figure 3. Where required, a manufacturer may specify the use of a loose spigot (not shown on Figure 3).Figure 3 — Sleeve coupler with shear studs (SS)7D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)3.3reduction coupler (RR and RS)right angle coupler (RR) or swivel coupler (RS) for connecting two tubes with different diameters of which one tube has a diameter of 48,3 mmNOTE See Figure 4.Figure 4 — Reduction coupler as swivel coupler (RS)4 SymbolsFor the purpose of this European Standard, the following symbols apply: c k characteristic stiffness of a longitudinal spring; F s slipping force in kN; F f failure force in kN; F p pull apart force in kN; F q share force in kN; M B bending moment in kNm;c φ(1),MB bending stiffness in kNm/rad; F s,c specified value for slipping force in kN; F f,c specified value for failure force in kN; F p,c specified value for pull apart force in kN;8D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)M B,c specified value for bending moment in kNm;c φ(1),MB,c specified value for bending stiffness in kNm/rad; ν displacement in millimetres of the transverse tube under load relative to a tube or solid bar inrotational tests;∆i displacement in millimetres of a coupler under load relative to a tube or solid bar; ∆10 indentation in millimetres; P test load in kN; P ind test load for indentation in kN; P f,ult ultimate failure force in kN;P p,ult ultimate pull apart force in kN;P q,ult ultimate share force in kN; φ specified angle of rotation of a coupler in degrees.5 Types and classification of special couplersThe types of special couplers are listed in Table 1. The classification is given in Table 2.9D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Table 1 — Types of couplersTable 2 — Classification of couplers6 Transmissible internal forces, moments and related stiffnesses6.1 GeneralIn general a connection between two members is able to transmit three internal forces and three moments at right angle. There are related stiffnesses.The connection of a tube to another member by a threaded element fixed half coupler (HT) or by weldable half coupler (HW) is designed to transmit three forces. Additionally, a Class B half coupler connected by a welded-in threaded element (HT) is designed to transmit one bending moment and a Class B screw weldable half coupler (HW) is designed to transmit two bending moments as listed in Table 3.A sleeve coupler with shear studs (SS) is designed to transmit one force and one bending moment as listed in Table 4.A right angle reduction coupler (RR) is designed to transmit three forces at right angle in three directions as listed in Table 5.A swivel reduction coupler (RS) is designed to transmit one force as listed in Table 6.NOTE The influence of the moments resulting from eccentricities of the connection is considered in the test.10D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)6.2 Half couplerTable 3 shows the structural parameters which are specified.Table 3 — Structural parameters for half couplers (HT and HW)ClassStructural parameters (see Figure 5)AHW/HTScrew coupler BHWHT Wedge couplerSlipping force F s■ ■ ■ ■ Failure force F f ■ ■ ■ ■Force or momentPull apart force F p Shear force F q ■ ■ ■ ■ ■ ■ ■ ■ Bending moment M B,x— ■ — — Bending moment M B,y — ■ ■ ■Connection stiffnessBending stiffness c ϕ,MB,x Bending stiffness c ϕ,MB,y— ■ — — — ■■■■ Structural parameters are specified in Table 8.Keyx,y direction of principal axisFigure 5 — Forces and moments for a half coupler11D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)6.3 Sleeve coupler with shear studs (SS)Table 4 shows which structural parameters are specified.Table 4 — Structural parameters for a sleeve coupler with shear studs (SS)Structural parameterSee Figure 6UnclassifiedFailure force F f■ Bending moment M B ■■ Structural parameters are specified in Table 8.Figure 6 — Forces and moments for a sleeve coupler with shear studs (SS)6.4 Reduction couplerTables 5 and 6 show the structural parameters specified.Table 5 — Structural parameters for a right angle reduction coupler type (RR)Tube Structural parametersee Figure 7UnclassifiedSlipping force F s,1 ■ 1 Diameter 48,3 mmFailure force F f,1■ Slipping force F s,2 ■ 2 Diameter different from 48,3 mmFailure force F f,2 ■ Pull-apart force F p■■ Structural parameters are specified in Table 8.12D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Key1 tube 1 48,3 mm outside diameter2 tube 2 of a different outside diameterFigure 7 — Forces for a right angle reduction couplerTable 6 — Structural parameters for a swivel reduction coupler type (RS)Tube Structural parameter(see Figure 8)UnclassifiedSlipping force F s,1 ■ 1 Diameter 48,3 mmFailure force F f,1■ Slipping force F s,2 ■ 2 Diameter different from 48,3 mm Failure force F f,2■■ Structural parameters are specified in Table 8.13D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Key1 tube 1 48,3 mm outside diameter2 tube 2 of a different outside diameterFigure 8 — Forces for a swivel reduction coupler (RS)7 Reference tubes/bar for coupler testsFor the purpose of testing, reference tubes and solid bars with a diameter of 48,3 mm shall be in accordance with EN 74-1.The tubes used for testing reduction couplers with diameters other than 48,3 mm shall be in accordance with Table 7, in which the diameters may have a deviation of ± 0,5 mm.Table 7 — Steel reference tubes RT R(n) for reduction couplers other than 48,3 mm outside diameter Outside Wall Wall thickness Yield stress Steel ndiameter thickness tolerance (includingreferencefinishing) (mm)(mm) (mm)(N/mm²)1 38,0 242,4 RT R(n)3 60,3 463,5 576,13,2+0,1 235 ≤ R eH ≤ 265-0,24,0 4,514D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)8 General requirements8.1 MaterialsAll members of couplers shall conform to the requirements specified in clause 6.1 of EN 74 -1:2005.The bodies of half couplers (HW and HT) shall conform to the welding requirements for execution Class 2 (EXC2) of EN 1090-2:2008. A threaded element shall be weldable and correspond as a minimum to M14 and strength Class 5.6 specified in EN ISO 898-1:1999.8.2 Design8.2.1 All couplers and coupler members shall conform to the requirements specified in clause 6.2.2, 6.2.3 and 6.2.6 of EN 74-1:2005.8.2.2 A coupler of a specified type shall conform to all requirements specified in Table 8. It means for any structural parameter that the evaluated test results shall achieve at least the specified values in this standard. Except for indentation, each value evaluated from a set of tests shall be equal to or greater than the specified value.NOTE The slipping resistance is dependent on the bolt tension. For a given torque this tension is considerably increased when the integral friction coefficient on the thread is low. This integral friction coefficient is significantly influenced by the type of corrosion protection and by the lubrication of the bolt and nut connection.8.2.3 Half couplers may be manufactured from parts of swivel couplers in accordance with EN 74-1 (half swivel couplers) or as a separate member.For a half coupler (HT), the threaded element for bolting to the other member shall be welded into the half coupler body with a surrounding line of welding.The body of a half coupler (HW) shall be welded to the other member with a surrounding line of welding to exclude air.The welding procedures shall be carried out in accordance with execution Class 2 (EXC2) of EN 1090-2:2008. 8.2.4 Sleeve couplers with shear studs shall be able to connect tubes with holes in accordance with the dimensions given below and to conform to the requirements given in 8.2.2.The distance between the end of a tube and each centre of the hole shall be 32,5 mm ± 1 mm. The diameter of the hole shall be 14 mm ± 0,5 mm.If required by the manufacturer a loose spigot should be used.15D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Table 8 — Tests parameters and specified values16D a i m l e r A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Table 8 (continued )8.3 Manufacturer’s drawingsFor each coupler model, the manufacturer shall record on the drawings sufficient information for unambiguous identification and as a base for subsequent inspection. This includes: a) geometry;b) dimensions and tolerances; c) mass with tolerance;d) material specification for each element of the coupler; e) type of surface protection of each element of the coupler.8.4 Production control8.4.1 An appropriate method of quality control during each production programme shall ensure that couplers satisfy the performance requirements of this standard and that they conform to the manufac turer’s drawings.When the ongoing production control follows one of the inspection methods set out in Annex A, it can be assumed that the couplers produced under this regime conform to the requirements of this clause.8.4.2 When ongoing production control procedures differ from those recommended in Annex A, they should be drawn up by a person competent do so.NOTE Although it is not a requirement of this standard, it is recommended that manufacturers submit their production control procedures periodically to third party inspections .9 Tests methods and evaluation of results9.1 GeneralBasic requirements for testing are given in EN 12811-3.Requirements for testing shall conform to clauses 7.1.2 to 7.1.11 of EN 74-1:2005.The minimum number of tests carried out on different types and classes of each coupler shall be in accordance with Table 9.17A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)Any aspects of the evaluation of tests results where not specified in this standard shall be carrie d out in accordance with EN 12811-3.Table 9 — Minimum number of tests for each coupler type9.2.1 GeneralIf a coupler can be used both as a weldable half coupler (HW) (without a welded-in threaded element) and as a half coupler connected by a welded-in threaded element (HT), only the less favourable coupler type need be tested.9.2.2 Slipping force F s of a half coupler 9.2.2.1Purpose of testTo determine the resistance F s of a coupler to slipping along a tube and the relative displacements between the tube and the other member.A G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)9.2.2.2Test arrangementsConnect the coupler to a member by welding (HW) or by welded-in threaded element (HT). If both applications are to be used, tests shall be carried out with couplers connected by welding (HW). Provide equipment to apply a test load P to the tube at the axis of the tube, see Figure 9. Make provision for measuring the displacement ∆2 between the tube and the member and ∆1 between the back of the coupler and the tube.Key1 rigid structural member2 reference tube3 half couplerFigure 9 — Test arrangement for slipping test of a weldable half coupler9.2.2.3Requirements for pre-loadsThe zero for both load-displacement measurements shall be set under a pre-load of 0,4 kN. 9.2.2.4Test procedureThe connection shall be subjected to a load P (i) applied axially. The displacements ∆i of the couplers shall be measured.The test load P (i) shall be increased uniformly at a rate of loading not exceeding 0,3 kN per second until the coupler begins to slip. Thereafter, a rate of slip of 2,0 mm per minute shall not be exceeded. The plotted load displacement curves P (i) = f (∆i ) shall include at least one displacement measuring point for every 1,0 kN increase in load P .Load displacement curves P (i) = f (∆i ) shall be plotted until either:a) displacement ∆i reaches the maximum values given in Table 8; orA G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)b) test load P reaches a value of twice the specified force given in Table 8; orc) test load reaches a maximum value P max whereafter the load cannot be usefully increased further. 9.2.2.5Evaluation of test resultsThe slipping force F s(i) of the specimen is the lowest measured force between a displacement ∆2 of 1 and 2 mm.Analyse the values of F s(i) statistically in accordance with 10.5 of EN 12811-3:2002 to determine the 5 % quantile F s5%.9.2.3 Failure force F f of a half coupler9.2.3.1 Purpose of testTo determine the resistance F f of a coupler at failure. 9.2.3.2Test arrangementConnect the coupler to a member by welding (HW) or by a welded-in threaded element (HT). If both applications are to be used, tests shall be carried out with a coupler connected by welding (HW). The coupler shall be located touching the abutment, and shall be fixed on the solid bar to prevent the coupler sliding during the test. The abutment shall be on the side of the solid bar remote from the member. Provide equipment to apply a test load P to the tube at the axis of the tube, see Figure 10. Key1 rigid structural member2 reference tube3 half coupler4 abutmentFigure 10 — Test arrangement for failure testA G ;019 - H P C D 652 - G R /E Q S ;EN 74-2:2008 (E)9.2.3.3Test procedureIncrease the test load P (i), displacement controlled with not more than 2 mm per minute, until either:a) coupler member fractures; orb) test load P (i) reaches a value after which the load cannot be usefully increased.Each maximum load P max and the nature of the failure mode of the coupler shall be recorded. 9.2.3.4Evaluation of test resultsAnalyse the values of P max statistically in accordance with 10.5 of EN 12811-3:2002 to determine the 5 % quantile F s5%.Apply an additional partial safety factor γR2 which shall be taken either as 1,25 or may be determined inaccordance with EN 12811-3.9.2.4 Pull-apart force F p of a half coupler 9.2.4.1Purpose of testTo determine the resistance of F p given by the coupler to separation of the tube and the structural member. 9.2.4.2Test arrangementConnect the coupler to a structural member by welding (HW) or by welded-in threaded element (HT). If both applications shall be used, the test shall be carried out with the coupler connected by welded-in threaded element (HT). Provide equipment to apply half the test load P /2 to the tube at two points equidistant from the axis of the coupler, see Figure 11. Key1 rigid structural member2 half coupler3 solid reference barFigure 11 — Test arrangement for pull apart test for a threaded element fixed half coupler。

超声弹性成像在肝脏病变中的应用

超声弹性成像在肝脏病变中的应用蒋孝鸣【摘要】Ultrasound elastography is a new type of ultrasonic diagnosis technology.At present,it is extensively used in the small organs,such as breast,thyroid and prostate.But in the liver lesions,its application is less.Medical researchers have been trying achieve accurate and non-invasive diagnosis of hepatic lesions,and elastography makes it possible.Here is to make a review of the literature about elastic imaging to improve the cognition about ultrasound elastography in liver diseases.%超声弹性成像是近些年发展起来的一种新型超声诊断技术,目前在乳腺、甲状腺、前列腺等小器官中应用较广泛,但在肝脏病变方面应用不多.医学研究者们一直在为如何做到无创、准确地检查肝脏病变而努力,而超声弹性成像使之成为可能,以下主要复习超声弹性成像在肝脏方面的文献报道,提高对超声弹性成像在肝脏疾病应用中的认识.【期刊名称】《医学综述》【年(卷),期】2013(019)012【总页数】3页(P2213-2215)【关键词】弹性成像;超声检查;脂肪肝;肝纤维化;肝硬化;恶性肿瘤【作者】蒋孝鸣【作者单位】安徽医科大学解放军174临床学院,福建厦门361000【正文语种】中文【中图分类】R445.1超声弹性成像技术于 1991年由 Ophir等［1］提出，随后逐渐发展为一种实时超声成像工具。

混凝土结构设计规范2010

《混凝土结构设计规范》 GB50010-20101引用标准名录1 《工程结构可靠性设计统一标准》GB 501532 《建筑结构可靠度设计统一标准》GB500683 《建筑结构荷载规范》GB 500094 《建筑抗震设计规范》GB 500115 《民用建筑热工设计规范》GB 501766 《混凝土结构工程施工规范》GB 50×××7 《建筑工程抗震设防分类标准》GB502238 《钢筋混凝土用钢第2部分：热轧带肋钢筋》GB 1499.2本规范用词说明1 为了便于在执行本规范条文时区别对待，对要求严格程度不同的用词说明如下：1）表示很严格，非这样做不可的用词：正面词采用“必须”；反面词采用“严禁”。

2）表示严格，在正常情况下均应这样做的词：正面词采用“应”；反面词采用“不应”或“不得”。

3）表示允许稍有选择，在条件允许时首先这样做的词：正面词采用“宜”；反面词采用“不宜”。

表示有选择，在一定条件下可以这样做的，采用“可”。

2 规范中指定应按其它有关标准、规范执行时，写法为：“应符合……的规定”或“应按……执行”。

1 总则21.0.1为了在混凝土结构设计中贯彻执行国家的技术经济政策，做到安全、适用、经济，保证质量，制定本规范。

1.0.2本规范适用于房屋和一般构筑物的钢筋混凝土、预应力混凝土以及素混凝土结构的设计。

本规范不适用于轻骨料混凝土及特种混凝土结构的设计。

1.0.3本规范依据现行国家标准《工程结构可靠性设计统一标准》GB 50153及《建筑结构可靠度设计统一标准》GB50068的原则制定。

本规范是对混凝土结构设计的基本要求。

混凝土结构的设计除应符合本规范外，尚应符合国家现行有关标准的规定。

32术语、符号2.1 术语2.1.1混凝土结构concrete structure以混凝土为主制成的结构，包括素混凝土结构、钢筋混凝土结构和预应力混凝土结构等。

2.1.2素混凝土结构plain concrete structure无筋或不配置受力钢筋的混凝土结构。

2010塑性变形机制第二章

滑移带示意图
滑移

定义：在切应力作用下，晶体的一部分相对于另一部分沿着一定的晶面（滑移面）和晶向（滑移方向）产生相对位移，且不破坏晶体内部原子排列规律性的塑变方式。滑移的机制就是位错在滑移面内的运动。滑移时，滑移矢量与柏氏矢量平行。晶体两部分的相对位移量是原子间距的整数倍. 滑移后, 滑移面两侧晶体的位向关系未发生变化。滑移分别集中在某些晶面上，变形具有不均匀性。
A0
滑移面上沿滑移方向的分切应力:
S
A
S cos cos cos
滑移面上的正应力:
n S cos cos2 s c
外力在滑移方向的分切应力
c s cos cos c s cos cos
只有 c一定时与 s
c
三种常用金属的临界分切应力随温度的变化
化学成分和温度对纯铜的临界分切应力的影响
镉速率的关系单晶的临界切应力与温度和应变
(X比+应变速率大100倍)
2.1.4滑移时晶体的转动（Rotation of Crystal)
实际变形中滑移总要受到限制，晶体不会自由无限制滑移下去，因此滑移的同时往往伴随着晶体的转动。 1. 位向和晶面的变化

单晶体的圆柱试样表面抛光后拉伸，试样表面就会出现一系列平行的变形痕迹。光镜观察，晶体表面上形成的浮凸，称为滑移带。
在300℃ 拉伸的锌单晶体
工业纯铁压缩变形——滑移线（电镜下）
滑移线（Slip Line）：滑移带中的细线．滑移线是滑移面两侧晶体相对滑动所造成的。滑移带和滑移线间的晶体片层并未发生塑性变形，仅仅发生了相对滑动。滑移层(Slip Lamina)：相邻滑移线间的晶体片层．滑移量( Slippage)：每条滑移线所产生的台阶高度．

医疗器械 ASTM标准一览表

ቤተ መጻሕፍቲ ባይዱMedical Device Standards and Implant Standards 医疗器械标准和植入标准
Designation
F2383 - 11 F1223 F1357 F1378 F1672 F1714 F1781 F1800 F1814 F1820 F1829 F2009 F2025 F2028 F2033 F2068 F2083 F2091 F2345 F2385 F2580 F2582 F2665 F2722 F2723 F2724 14 14 12 14 96(2013) 03(2009) 12 97a(2009) 13 98(2009) 00(2011) 06(2012) 14 12 15 12 15 03(2013) 04(2010) 13 14 09(2014) 15 13a 08(2014) Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard Standard
F2777 - 10 F2887 - 12 F2943 - 14 F2978 - 13 F2979 - 14 F2996 - 13 F3047M - 15 F2451 - 05(2010) F2529 - 13 F2721 - 09(2014) F2884 - 12 F2903 - 11
E1262 - 88(2013) F619 - 14 F719 - 81(2012) F720 - 13 F748 - 06(2010) F749 - 13 F750 - 87(2012) F756 - 13 F763 - 04(2010) F813 - 07(2012) F895 - 11 F981 - 04(2010) F1027 - 86(2012) F1408 - 97(2013) F1439 - 03(2013) F1877 - 05(2010) F1903 - 10 F1904 - 14

润滑脂检测方法国内外标准对照表

美国测试标准中国测试标准德国测试标准测试项目ASTM D1298GB/T 1884DIN 51757密度ASTM D1500GB/T 6540DIN 51578颜色ASTM D217GB/T 269DIN 51804润滑脂锥入度ASTM D566GB/T 4929DIN 51801润滑脂滴点ASTM 2265GB/T 3498DIN 51801润滑脂宽温滴点ASTM D2783GB/T 3142DIN 51350润滑脂承载能力(PB)(四球法)ASTM D2783GB/T 12583DIN 51350润滑脂极压性(PD)(四球法)ASTM D2782GB/T 11144DIN 51350润滑脂极压性能(梯姆肯法)ASTM D6184SH/T 0324DIN 51817润滑脂分油量(静态法)ASTM D942SH/T 0325DIN 51808润滑脂氧化安定性(双氧弹法)ASTM D217GB/T 269DIN 51804润滑脂机械安定性(剪切法)ASTM D1831SH/T 0122DIN 51819E 润滑脂机械安定性(滚筒法)ASTM D1264SH/T 0109DIN 51807润滑脂抗水淋性ASTM D1092SH/T 0048润滑脂相似粘度ASTM D1743GB/T 5018DIN 51811润滑脂防腐蚀性ASTM D4048GB/T 7326DIN 51759润滑脂铜片腐蚀ASTM D1478SH/T 0338DIN 51757润滑脂低温转矩ASTM D1263SH/T 0326润滑脂轴承漏失量ASTM D3336SH/T 0428DIN 51806润滑脂高温轴承寿命ASTM D972GB/T 7325DIN 51581润滑脂蒸发损失ASTM D471SH/T 0305DIN 53521密封适应性ASTM D877GB/T 507DIN 57370击穿电压ASTM D95GB/T 512DIN 51582水分(蒸馏法)ASTM D92GB/T 267DIN 51376开口闪点ASTM D1404SH/T 0322润滑脂有害粒子鉴定FS791B335.2SH/T 0427润滑脂齿轮磨损ASTM D5483SH/T 0790润滑脂抗氧化性能试验（氧化诱导期）ASTM D2266SH/T 0204抗磨性能(四球机法)磨痕直径 mmDIN 51805润滑脂流动压力测试方法，mbar。

结构计算书

Abstract
The design is the 3 residential building for Rose Garden frist phase , it main body is seven layer frame structure.The design includes two parts: Architectural Design and Structural Design.The building's height of the each floor are 3 meters. The height of the whole building is 22.50meters. The first part is the Architectural Design,which includes drawing the floor plan, elevation, section,as well as General introduction of the architectural design.Then we can make sure the building in the total plane layout is defined according to the buildings classification,which according to the conditions for building. Structure design is to determine the structure project based on the preliminary design of the building; and then select a reasonable structure system; then we could carry out the structural layout and a preliminary estimate,finally we could confirm the structural element size and carry on the structure calculation. Structure calculation includes load calculation, internal force calculation, internal force combination, cross section design, foundation design etc.. After determining the calculation diagram, we can select a frame is calculated, when considering the structure under a variety of condition like dead load, live load, wind load, using the D value method to calculate the internal force (bending moment, shear force,axial force) of the structure under the lateral wind loads ,calculation of vertical load(constant load and live load) using a delamination method under the internal forces, and then by the internal force combination of internal forces, and carry out the framework reinforcement. The roof is master roof, use the single board design. The foundation uses the independent foundation , its calculation including load calculation, the calculation of bearing capacity of foundation. In short, application, security, economic, easy to use is the principle of design, architectural space layout reasonable, compact connection, prioritize, make the building to improve comfort. Key words: portal frame construction; architectural design; structural design; endogenic force combination; section design .

外文翻译模板

Waste Management 30 (2010) 1544–1555Large-scale direct shear testing of municipal solid waste Dimitrios Zekkos a,*, George A. Athanasopoulos b, Jonathan D. Bray c, Athena Grizi b, AndreasTheodoratos ba Department of Civil and Environmental Engineering, University of Michigan, 2358 GG BrownLaboratory, 2350 Hayward Street, Ann Arbor, MI 48109, USAb Dept. of Civil Engineering, Univ. of Patras, 26500 Rion, Greecec Department of Civil and Environmental Engineering, University of California at Berkeley, CA94720-1710, USAABSTRACTLarge direct shear testing (300 mm _ 300 mm box) of municipal solid waste (MSW) collected from a landfill located in the San Francisco Bay area was performed to gain insight on the shear response of MSW. The study investigated the effects of waste composition, confining stress, unit weight, and loading rate on the stress–displacement response and shear strength of MSW. The amount and orientation of the fibrous waste materials in the MSW were found to play a critical role. The fibrou s material had little effect on the MSW’s strength when it was oriented parallel to the shear surface, as is typically the case when waste material is compressed vertically and then tested in a direct shear apparatus. Tests in which the fibrous material was oriented perpendicular to the horizontal shear surface produced significantly stronger MSW specimens. The test results indicate that confining stress and loading rate are also important factors. Based on 109 large-scale direct shear tests, the shear strength of MSW at low moisture contents is best characterized by cohesion = 15 kPa, friction angle = 36_ at a normal stress of 1 atmosphere, and a decrease in the friction angle of 5_ for every log-cycle increase in normal stress.1. IntroductionThe response in shear of municipal solid waste (MSW) is an important consideration in landfill design, particularly for the evaluation of a landfill’s static and seismic stability. Several MSW landfill instabilities have occurred in recent years, including the Rumpke Landfill in Ohio (Eid et al., 2000), Dona Juanna Landfill in Colombia (Hendron et al., 1999), Payatas Landfill in Philippines (Kavazanjian and Merry, 2005), and Java landfill in Indonesia (Koelschet al., 2005). These failures had significant economic consequences and in some cases resulted in the loss of human life. An improved understanding of the shear response of MSW is required to support sound stability evaluations of landfills.With the aim of providing insights regarding the mechanical response of MSW, acollaborative research program that involved the University of California at Berkeley, Arizona State University, Geosyntec Consultants, University of Patras (Greece), and the University of Texas at Austin was undertaken. One of its primary objectives was to evaluate the static and dynamic properties of MSW by systematically characterizing and testing MSW in the field and laboratory. Findings of the collaborative investigation are summarized in Zekkos et al. (2008a). Recommendations for estimating the unit weight of MSW (Zekkos et al., 2006) and the dynamic properties of MSW (Zekkos et al., 2008a) have been presented elsewhere. An overall assessment of the shear strength of MSW using.2. Literature reviewThe strength envelope recommended by Kavazanjian et al. (1995) is often used in engineering practice to characterize the shear strength of MSW. This bilinear strength envelope consists of a purely cohesive material with cohesion (c) of 24 kPa for normal stresses up to 30 kPa and a purely frictional material with a friction angle (/) of 33_ at higher normal stresses. The envelope was intended to be a conservative estimate of the shear strength of MSW; it was based on a limited number of laboratory and field tests and the back-calculation of stable waste slopes. More recently,Eid et al. (2000) relied on a larger database of laboratory data and back-calculations of three unstable slopes in developing a linear shear strength envelope that was characterized on average by c = 25 kPa and / = 35_. Zekkos (2005) performed an extensive review of the literature and identified significant differences in the MSW shear strength parameters proposed by other researchers. Mohr–Coulomb strength parameters with cohesions varying from 0 to 80 kPa and friction angles varying from 0_ to 60_ have been proposed by several different researchers (Fig. 1). The selected value of the cohesion and friction angle used in conducting andfill analyses is obviously critical.3. Characterization of the waste tested in this studyTwo large-diameter (760 mm) borings were augered to depths of 10 m and 32 m using a bucket auger at the Tri-Cities landfill, located in the San Francisco Bay area in north California. Bulk waste samples from small and large depths, varying in age from 0 to 15 years old, were retrieved and stored separately in 39 sealed 55-gallon drums of bulk waste material. Excessive grinding of the waste particles was not observed, so the collected waste materials are assumed to be unprocessed. Two to four drums of waste were collected at each 3 m sampling interval. The in situ unit weight of waste was measured using the procedures described in Zekkos et al. (2006). Its unit weight increased from 10 kN/m3 near the surface to 16 kN/m3 at greater depths. Waste material was transported to the Richmond Field Station of the University of California at Berkeley, where it was characterized. Waste characterizationincluded separating the waste material into material larger and smaller than 20 mm. This segregation is considered useful, because material <20 mmis composed of soil-like material that is derived primarily from daily cover, other soil materials, and some fine waste inclusions, whereas material >20 mm generally consists of bulk and fibrous waste materials. Additionally, material <20 mm can be characterized using conventional soil mechanics index tests, such as sieve analyses and Atterberg limits, and it can be tested using geotechnical testing equipment.Waste samples that were collected as part of this study form three general classes. Class A is relatively ‘‘deep old waste” and included sample groups A1–A4. Class B is ‘‘deep old waste with fibrous <20 mm material” and included sample group B1. Class C is ‘‘shallow fresh waste” and included sample groups C1–C6. Classes A and B waste were placed in 1987; whereas Class C waste was placed after 1999. The percentage by weight of the <20 mm material and the amount of plastic, paper, wood, gravel and other constituents of the >20 mm material were measured for a total of 6 waste sample groups. The mass of the processed samples varied from 60 to 320 kg. About 50–75% of the total waste sample by weight was <20 mm material, and the >20 mm material consisted primarily of paper, plastic, wood, and gravel. Other constituents such as metals, glass, stiff plastics, and textiles, comprised a significantly lower percentage of the material by weight and by volume. Details of the field investigation and waste characterization are provided in Zekkos (2005).ReferencesAthanasopoulos, G., Grizi, A., Zekkos, D., Founta, P., Zisimatou, E., 2008. Municipal Solid Waste as a Reinforced Soil: Investigation Using Synthetic Waste. ASCE, GSP No. 177, pp. 168–175.Bray, J.D., Zekkos, D., Kavazanjian Jr., E., Athanasopoulos, G.A., Riemer, M.F., 2009. Shear strength of municipal solid waste. Journal of Geotechnical and Geoenvironmental Engineering, ASCE 135 (6),709–722.Caicedo, B., Yamin, L., Giraldo, E., Coronado, O., 2002. Geomechanical properties of municipal solid waste in Dona Juana sanitary landfill. In: Proceeding of the Fourth International Congress on Environmental Geotechnics, Brazil, vol. 1, pp. 177–182.Duncan, J.M., Wright, S.G., 2005. Soil Strength and Slope Stability. John Wiley & Sons Inc.. Edincliler, A. Benson, C.H., Edil, T.B., 1996. Shear strength of municipal solid waste. Interim Report –Year 1, Environmental Geotechnics Report 96-2, Department of Civil and Environmental Engineering, University of Wisconsin, Madison.Eid, H.T., Stark, T.D., Douglas, W.D., Sherry, P.E., 2000. Municipal solid waste slope failure 1. Waste and foundation properties. Journal of Geotecnical and Geoenvironmental Engineering, ASCE 126 (5), 397–407. Gabr, M.A., Valero, S.N., 1995. Geotechnical properties of municipal solid waste. Geotechnical Testing Journal 18, 241–254.Grizi, A., 2006. Mechanical Behavior of MSW-Laboratory Test Results in Large Shear Box Apparatus. Diploma Thesis, Department of Civil Engineering, University of Patras, Patras (in Greek).Hendron, D.M., Fernandez, G., Prommer, P.J., Giroud, J.P., Orozco, L.F., 1999. Investigation of the cause of the 27 September 1997 slope failure at the Dona Juana landfill. In: Proceedings of Sardinia, p. 99. Houston, W.N., Houston, S.L., Liu, J.W., Elsayed, A., Sanders, C.O., 1995. In situ testing methods for dynamic properties of MSW landfills. Earthquake design and performance of solid waste landfills. ASCE Geotechnical Special Publication No. 54, pp. 73–82.Kavazanjian Jr., E., Matasovic, N., Bonaparte, R., Schmertmann, G.R.,1995. Evaluation of MSW properties for seismic analysis. Geoenvironment 2000. Geotechnical Special Publication No. 46, pp.1126–1141.Kavazanjian Jr., E., 1999. Seismic design of solid waste containment facilities. In: Proceedings of the Eighth Canadian Conference on Earthquake Engineering. Vancouver, BC, pp. 51–89.Kavazanjian Jr., T., Merry S.M., 2005. The 10 July 2000 Payatas landfill failure. In: Proceedings of Sardinia.Koelsch, F., Fricke, K., Mahler, C., Damanhuri, E., 2005. Stability of landfills – the Bandung dumpsite disaster. In: Proceedings of Sardinia.Landva, A.O., Clark, J.I., 1986. Geotechnical testing of wastefill. In: Proceedings, 39th Canadian Geotechnical Conference Ottawa, Ontario, pp. 371–385.Landva, A.O., Clark, J. I., 1990. Geotechnics of waste fill. In: Landva and Knowles (Ed.), Theory and Practice, STP 1070, ASTM, pp. 86–103.Mahler, C.F., De Lamare Netto, A., 2003. Shear resistance of mechanical biological pre-treated domestic urban wast. In: Proceedings Sardinia 2003, Ninth International Waste Management and Landfill Symposium, 6–10 October 2003.Matasovic, N., Kavazanjian, E. Jr., 1998. Cyclic characterization of OII landfill solid waste. ASCE, Journal of Geotechnical and Geoenvironmental Engineering 124(3), 197–210.Mazzucato, N., Simonini, P., Colombo, S., 1999. Analysis of block slide in a MSW landfill. In: Proceedings Sardinia 1999, Seventh International Waste Management and Landfill Symposium, Cagliari, Italy, 4–8 October 1999.Pelkey, S.G., 1997. Geotechnical properties of municipal solid waste. Thesis submitted in partial fulfillment of the requirements for the degree of Masters of Science in Engineering, Department of Civil Engineering, The University of New Brunswick.Richardson, G., Reynolds, D., 1991. Geosyntetic considerations in a landfill on compressible clays. Procee dings of Geosynthetics ‘91, vol. 2. Industrial Fabrics Association International, St. Paul, MN. Siegel, R.A., Robertson, R.J., Anderson, D.G., 1990. Slope stability investigations at a landfill in southern California, American Society for Testing and Materials, ASTM. Special Technical Publication, STP 1070,pp. 259–284.Stoll, O.W., 1971. Mechanical properties of milled refuse. In: ASCE National Water Resources Engineering Meeting, Phoenix, Arizona, January 11–15.Theodoratos, A., 2007. Evaluation of MSW Shear Strength With Laboratory Direct Shear Testing. M.Sc. Thesis, Department of Civil Engineering, University of Patras, Patras (in Greek).Vilar, O.M., Carvalho, M.F., 2002. Shear strength properties of municipal solid waste. In: Proceeding of the Fourth International Congress on Environmental Geotechnics, Brazil, vol. 1, pp. 59–64.Withiam, J.L., Tarvin, P.A., Bushell, T.D., Snow, R.E., German, H.W., 1995.Prediction and performance of municipal landfill slope. In: Proceedings nternational Conference the Geoenvironment 2000, ASCE GSP No. 46, NY, pp. 1005–1019.Zekkos, D.P., 2005. Evaluation of static and dynamic properties of municipal solidwaste. Ph.D. Thesis, Department of Civil and Environmental Engineering,University of California at Berkeley.Zekkos, D., Bray, J.D., Kavazanjian Jr., E., Matasovic, N., Rathje, E.M., Riemer, M.F., Stokoe, K .H., 2006. Unit weight of municipal solid waste. ASCE Journal of Geotechnical and Geoenvironmental Engineering 132 (10), 1250–1261.Zekkos, D., Bray J.D., Athanasopoulos, G.A., Riemer, M.F., Kavazanjian, E., Founta, X., Grizi, A., 2007. Compositional and loading rate effects on the shear strength of municipal solid waste. In: 4th International Conference on Earthquake Geotechnical Engineering, Thessaloniki, Greece, June 25–28, 2007, Paper No. 1525.Zekkos, D., Bray, J. D., Stokoe, K., Kavazanjian, E., Rathje, E., Athanasopoulos, G.A., Riemer, M., Matasovic, N., Lee, J.J., Seos, B., 2008a. Recent Findings on the Static and Dynamic Properties of Municipal Solid Waste, ASCE-Geoinstitute Geocongress 2008a, Geotechnics of Waste Management and Remediation. Geotechnical Special Publication (GSP) No. 177, pp. 176–183.Zekkos, D., Bray, J.D., Riemer, M .F., 2008b. Large-scale cyclic triaxial characterization of the dynamic properties of municipal solid waste. Canadian Geotechnical Journal 45 (1), 45–58.废物管理30 (2010) 1544–1555大规模的都市固体废物直接剪切试验Dimitrios Zekkos a,*, George A. Athanasopoulos b, Jonathan D. Bray c, Athena Grizi b, AndreasTheodoratos ba土木与环境工程学院，密歇根大学，布朗实验室，海沃德街，安阿伯，美国b土木工程系，大学。

基于修正压力场理论的有腹筋钢筋混凝土受弯构件受剪计算

136
主压应变 ε2 和平均竖向应变 ε z 。对于有腹筋梁，假定剪切破坏时裂缝处和裂缝间的箍筋均达到屈服强度，即 f szcr = f sz = f yv ，其中 f szcr 为横向裂缝处的应力； f yv 为箍筋屈服强度。因此由 10］文献［的式（ 5 ）可得到修正压力场理论的截面剪应力为： v as = v a + ρ v f yv cot θ （ 2）。 2 ）式中： ρ v 为配箍率由式（可看出，修正压力场理论的受剪承载力是由沿裂缝面传递的剪应力即骨料咬合力和箍筋共同承担的。
《欧洲模式规范》（草案）混凝土结构受剪设计方法的基础。然而，修正压力场理论认为有腹筋构件的受剪承载力由沿裂缝面传递的剪应力和穿过裂缝面的箍筋提供，忽略了上部受压区混凝土对抗剪的贡献，因而计算的受剪承载力偏小。对于无腹筋钢筋混凝土梁，研究表明受压区混凝土可承受 20% ～ 40% 的剪力，因此考虑受压区提供的抗剪作用是有必要的。混凝土受压起两方面的作用，一方面是平衡弯矩产生的纵向受拉钢筋的拉力，另一方面是提供抗剪能力。为此，本文基于同时考虑上部受压区混凝土、下部受拉区骨料咬合力及箍筋共同提供的抗剪能力，上部受压区按弯曲理论分析，下部受拉区采用修正提出了有腹筋钢筋混凝土构件抗剪强压力场理论，度的计算方法。
［3-4 ］
，开辟了一条
已经得到解决钢筋混凝土构件受剪问题的新途径， 1994 ，国际上的广泛认可，并成为 AASHTO LRFD［5 ］ 2007《美国桥梁结构设计规范》、 CSA A23. 394 、［6 ］ CSA A23. 3-04《加拿大混凝土结构设计标准》、［7 ］ CSA 2000《加拿大公路桥梁设计标准》和 MC 2010

犬作为动物模型在生物医学领域的研究应用

文章编号：1004-2342（2023）05-0040-04中图分类号：S829.2文献标识码：A犬作为动物模型在生物医学领域的研究应用李强，魏荣兴，余传刚，李涛*(公安部南昌警犬基地,江西南昌330100)摘要：犬作为人类最亲密的动物之一，具有品种丰富、数量庞大、遗传背景清晰稳定等特点，同时在解剖学特征、生活环境、病因和病情发展、药物代谢等方面与人类相似，已在心血管系统、内分泌系统、消化系统等领域广泛应用，建立了一系列类似于人类疾病的动物模型如腹主动脉瘤模型、动脉粥样硬化模型、肺动脉高压模型、2型糖尿病模型、肥胖模型、胰腺缺血模型、急性重症胆管炎模型、溃疡性结肠炎模型等，展现了犬作为动物模型在生物医学领域的应用具有巨大潜力。

本文主要介绍犬模型的应用种类、制备方法和病情症状等，为深入分析发病机制、药物治疗、并发症及预防措施等提供参考。

关键词：犬；动物模型；心血管系统；内分泌系统；消化系统人类疾病病情复杂，症状繁多，主要受遗传因素和环境因素的影响，病例样本不易收集。

人体实验在伦理和方法上受到限制，且实验研究周期漫长，为避免人体实验带来的伤害，一般利用动物模型来进行人体医学研究实验，探索人类疾病的发病机制和病情进展，寻找预防及治疗方法。

动物模型一般选择与人类的机能、代谢、结构以及疾病特征相似的易操作的实验动物，这类动物能较好的模拟人类疾病微环境，同时遗传背景清晰可查，生活环境与人类比较接近，饲养简单经济[1~2]。

犬作为与人类生活联系最为紧密的动物之一，其因为在生理结构、遗传病、生活环境等方面的独特优势而在生物医学动物模型领域受到广泛应用[3~4]。

1犬作为动物模型在医学领域中的优势犬作为动物模型在医学领域备受欢迎主要因为有以下几个优势：①犬品种资源丰富，目前世界上犬品种数量超过400余种[5]，其体型外貌各异，行为表现千差万别，其表型多样性和已知自然发生疾病种类仅次于人类[6]；同时犬饲养量多，根据《中国宠物行业白皮书-2022年中国宠物消费报告》，仅中国城镇犬数量高达5119万只。

径流涡轮叶尖间隙对叶片振动的影响研究

URANS
Computational fluid dynamics Excitation order Finite element analysis Fast-Fourier-Transform Fluid-structure interaction High cycle fatigue Pressure ratio Pressure surface Passage vortex Root mean square Suction surface Shear-stress transport model Tip leakage vortex Unsteady Reynolds averaged NavierStokes equations
*Fund Program: National Natural St No. 51606121).
· 46 ·
第 63 卷，2021 年第 3 期 Vol.63，2021,No.3
Lei Pan1 Ming-yang Yang1 Shouta Murae2 Wataru Sato2 Naoto Shimohara2 Akihiro Yamagata2
（1. Shanghai Jiao Tong University; China,2. IHI Corporation, Japan)
Abstract：With the increasing demand of turbochargers with high performance and low turbo lag, high cycle fatigue (HCF) of radial turbine blades has become the most common form of turbocharger failure. Tip clearance is the key to influencing the strength and evolution of tip leakage vortex which plays an important role in HCF due to the impact on aerodynamic excitation. This paper studies the influence of tip clearance on blade excitation of a vaneless radial turbine. One-way fluid-structure interaction numerical method is employed in this research, which is validated by experimental data. The results suggest that a‘V-shape’correlation exists between vibration amplitude and tip clearance. Generalized energy analysis indicates that complex distributions of harmonic pressure amplitude on the blade determine the‘Vshape’correlation. Flow field analysis further suggests that distributions of harmonic pressure amplitude on pressure surface and suction surface are both dominated by tip leakage vortex, whereas the mechanisms are quite different. Keywords：Tip Clearance; Aerodynamic Excitation; Vaneless Radial Turbine; High Cycle Fatigue

安东尼戴维斯 Antony Davis

安东尼·戴维斯 (born March 11, 1993) is an American professional basketball player for the New Orleans Hornets of the National Basketball Association (NBA). He played as a power forward for the 肯塔基大学 as a freshman before being selected first overall in the 2012 NBA Draft by New Orleans. He plays power forward and center. He was a 2012 NCAA Unanimous First team All-American and was the 2011–12 NCAA Division I men's basketball season blocks leader. He established Southeastern Conference single-season blocked shot s and NCAA Division I freshman blocked shots records. He has also earned the national Freshman, Defensive Player and Big Man awards. In addition, he has been named the 2012 National Player of the Year by various organizations, earning the Oscar Robertson Trophy, the Adolph Rupp Trophy, the Associated Press Player of the Year, Naismith Award, Sporting News Player of the Year and John R. Wooden Award. He was the Southeastern Conference's player, freshman and defensive player of the year. He helped lead Kentucky to a undefeated 2011–12 Southeastern Conference men's basketball season and was the NCAA Tournament Most Outstanding Player when Kentucky won the 2012 NCAA Men's Division I Basketball Tournament.As a high school basketball player for Chicago's Perspectives Charter School, he was unknown nationally and locally after three seasons of play in the lightly regarded Blue Division of the Chicago Public High School League. A "late bloomer", he emerged into prominence in April 2010 (the spring of his junior year) after a growth spurt and exposure on an Amateur Athletic Union(AAU) traveling team made him a blue chip prospect. Within months, he was the top-rated player in the national class of 2011 by and and the number two player by . He was a high school All-American by every major selector (ESPN, Jordan, McDonald's, Parade, USA Today) and earned Co-MVP honors at the 2011 Jordan Brand Classic.高中生涯Davis is from the South Side of Chicago and played high school basketball for Perspectives Charter School,[1] where he had attended school since sixth grade.[2] The team plays in a division of the Chicago Public High School League, known as the Blue Division, that is ignored by the media because of its lower level of competition.[3][4] Perspectives is a charter school that operates as a math and science academy with high academic pedigree, but minimal athletic success.[5][6] The school had no gymnasium and Davis' middle school basketball teams practiced at a nearby church.[4] In junior high school, he was known as "the little guy who would shoot threes from the corner".[3] He ended his freshman year at a height of 6英尺0英寸（1.83米）.[3] By the beginning of his sophomore year, he had grown another 1英寸（2.5厘米）, and he finished the year at 6英尺4英寸（1.93米）.[3][7]"The Chicago Sun-Times covered nearly 700 boys high school basketball games last season. Anthony Davis, who just might be the best high school player in the country, didn't play in any of them."—Michael O'Brien, Chicago Sun-Times (August 5, 2010).[3]As an unheralded guard after his sophomore season, he worked out with his cousins on guard drills that their father (Davis' uncle) had developed.[8] Davis did not play in the spring/summer AAU circuit between 8th grade and his junior year.[5] He began his junior year at a height of 6英尺7英寸（2.01米） and his junior basketball season at 6英尺8英寸（2.03米）,[3][7] saying he felt fortunate to have had such a rapid growth spurt without any knee pains.[9] During his junior year, his family considered having him transfer to one of Chicago's basketball powerhouses, but Hyde Park Career Academy head coach Donnie Kirksey, who knew Davis, Sr. well, advised against it saying "If you're good enough, they'll find you wherever you are."[3] Perspectives finished the season 8–15.[3] Although he remained unnoticed nationally and locally after three seasons of Chicago Public League play,[2][10] he was soon thereafter rated as the #1 player in the class of 2011 by [11] and in the ESPNU 100.[12] rated him the #2 player behind Austin Rivers.[13]The attention came when he started playing on Tai Streets' Meanstreets (AAU team) traveling system in the spring of his junior year.[3] As late as Spring 2010 he was still unknown, but began to be noticed in mid April.[3]In late April, Syracuse offered him a scholarship.[2]That spring NBA Top 100 Camp Director Dave Telep, invited him to the camp based on his dominant first half performance of the first game of the Fort Wayne, Indiana Spiece Fieldhouse event.[14] That summer his talent was attention-grabbing.[8] In August 2010, Davis played in the Nike Global Challenge in Hillsboro, Oregon. In the opening game, he had 23 points and 9 rebounds.[15]Davis verbally committed to Kentucky on August 13, 2010 amid a pay for play scandal,[13][16]choosing it over his other finalists, which were DePaul, Ohio State, and Syracuse.[17] He had officially visited DePaul and Ohio State.[16]On August 24, 2010, he became the number one rated player in the national class of 2011 at .[18]The pay-for-play scandal had played out very publicly in the press. Before Davis committed to Kentucky, the Chicago Sun-Times reported that his father, Anthony Davis, Sr. asked Kentucky for $200,000 for a commitment from his son.[19] The report wasinitially released on Wednesday August 4, 2010 by Sun-Times reporter Michael O'Brien.[20] Citing "a reliable source," he posted the following text "rumors/sources that have Davis choosing Kentucky are also alleging that the commitment cost $200,000." before it was edited to say "rumors that Davis' commitment is for sale have surfaced since he cut his list of schools down about a month ago." and then removed later that day from the Sun-Times' high school sports website following a threat from a University of Kentucky lawyer.[20] A Lexington, Kentucky law firm sent a letter under the signature of attorney Stephen L. Barker that expressed a "formal demand that you (O'Brien and the Sun-Times) withdraw the publication from any source from which it has been published, and issue an immediate statement that you know of no credible evidence indicating that there is any truth to the 'rumors' referred to in your article."[20] Baker's letter also threatened potential "punitive damages for your malicious and willful actions."[20] Anthony Davis Sr., declined to speak to the Chicago Tribune on August 4 regarding the allegation, although he denied the allegations to the Sun-Times stating "We haven't asked anyone for anything, and no one has offered us anything," on July 30 before the story broke.[20]The article was reposted on the Sun-Times' website and included in the print edition on Friday August 6 where O'Brien wrote "sources from three separate universities told the Sun-Times that Davis Sr. asked for money in return for his son's commitment, with the amounts ranging from $125,000 to $150,000."[21][22][23]The University of Kentucky and the Davis family both threatened to sue the Sun-Times over the article,[21][24]however, no lawsuits were filed by Kentucky or the Davis family. The Davises and Kentucky claim the restated publication was false.[25] Illinois' one-year statute of limitations on libel cases expired before any lawsuits were filed.[4]Davis signed his National Letter of Intent on November 10, 2010.[12][26] He began his senior season on the Chicago Sun-Times area 2010 Top 50 list.[27] He was a pre-season first team all-state selection by the Sun-Times along with Ryan Boatright(East Aurora/Connecticut), Wayne Blackshear(Morgan Park/Louisville), Mycheal Henry (Orr/Illinois), and Jabari Parker (Simeon/underclassman).[28] By that time, he stood at 6英尺10英寸（2.08米）.[3][7]According to Rodger Bohn of SLAM Magazine who saw him play more than 10 times, Davis retained his guard instincts after his growth spurt.[29] Despite Davis' individual prowess, Perspectives began the season with a 0–6 record.[30] He sat out one of those games with minor forearm and leg injuries.[31]It took a near quadruple double on December 15, 2010 against Benito Juarez Community Academy, when he posted 32 points, 21 rebounds, 11 assists and 9 blocked shot s for the team to earn its first victory in its seventh game.[7][32]The team's subsequent game against Whitney M. YoungMagnet High School played at Chicago State University was nationally televised on ESPNU.[33] Later in the season, he missed some games due to a sprained right thumb.[34]Despite losing approximately three-quarters of its regular season games, Perspective earned a Class 3A regional play-in game victory against Noble Street Charter High School in the Illinois High School Association state playoffs when Davis totaled 33 points, 9 rebounds, 7 assists, 5 blocked shots and 4 steals.[35] However, after losing the subsequent regional semifinal game to King College Prep High School the team finished with a 6–19 record.[36]Despite his growth, he continued to perform much of the role of a guard by bringing the ball up the court and shooting outside shots.[37] For the season, he averaged 32 points, 22 rebounds and 7 blocks.[17]Davis at Jordan Brand Classic (2011-04-19)In high school, Davis earned numerous honors for his basketball abilities including being named to the 2011 McDonald's All-American Game and the 10th annual Jordan Brand Classic.[38][39] Although he had not been rated in the Mr. Basketball USA poll to end the 2009–10 season, he began the 2010–11 season ranked fifth, which was the highest of previously unranked players and finished the season fourth behind Rivers, Mike Gilchrist(now known as Michael Kidd-Gilchrist) and Bradley Beal.[40][41] He joined those three and James Michael McAdoo as first team USA Today All-USA high school basketball team selections.[42][43]He was a first team Parade All-American.[44] He was also a first team All-American selection by SLAM Magazine (along with Gilchrist, Rivers, Beal, Quincy Miller and Marquis Teague) and Dime Magazine(along with Gilchrist, Rivers, Beal and Myles Mack).[45][46]He was a first team selection to the ESPN Rise boys' high school basketball All-American team.[47] However, in the statewide voting for the Illinois Mr. Basketball by coaches and media, he only placed fourth behindco-winners Boatright and Chasson Randle (Rock Island/Stanford) and third-place finisher Blackshear.[48] Those four and Abdel Nader (Niles North/underclassman) formed the Chicago Tribune All-State first team.[49] The Chicago Sun-Times selected him as a Class 3A first team All-State selection along with Blackshear.[50]The Chicago Sun-Times selected him as an all-Public League selection along with Blackshear, Parker, Henry andD. J. Tolliver.[51] The Illinois Basketball Coaches Association included him in the Class 3A/4A boys all-state first team.[52]In the March 30, 2011 McDonald's All-American Game, in front of a hometown crowd at the United Center, he made his first five field goals on his way to a 14-point, 6-rebound, 2-steal and 4-block performance.[53][54] In the April 9 Nike Hoops Summit, Davis led the USA Basketball team to a 92–80 victory over the world team with a team-high 10 rebounds to go along with 16 points and 2 blocks.[55][56]He was named co-MVP of the April 16 Jordan Brand Classic game (along with McAdoo) after posting 29 points (on13-for-15 shooting), 11 rebounds and 4 blocks in a losing effort.[57][58] Davis' 29 points was the second-highest point total in the first 10 years of the Jordan Brand Classic, following only LeBron James' 34-point performance.[58]Template:College Athlete Recruit Start Template:College Athlete Recruit Entry Template:College Athlete Recruit EndKentucky WildcatsDavis played at Kentucky for head coach John Calipari.Davis committed to the Kentucky Wildcats, coached by John Calipari. Before his college career began, he was being mentioned as the NBA draft first overall selection in the 2012 NBA Draft.[59][60][61] In late February Dick Vitale mentioned the possibility that Davis might complete the men's college basketball awards Grand Slam of National Player of the Year, Defensive Player of the Year, Freshman of the Year and the No. 1 overall pick in the upcoming draft."[37]During the exhibition portion of the season for the 2011–12 Wildcats, Calipari described Davis as follows: "He’s 6–10 with a 7–3 wingspan and he can shoot the 3 and dribble the ball and lead the break. . ."[62]Less than a month into the season, ESPN's Andy Katz described him similarly: "Davis offers a multitude of skills for the Wildcats with his ability to block shots, run the floor, score in the low post and face up to the basket."[63]Since Calipari had coached Marcus Camby, who was also a tall shot-blocker, Davis draws comparisons to Camby.[63]ESPNselected Davis as a preseason All-American along with teammate Terrence Jones.[64]Some sources, such as Blue Ribbon, selected Connecticut's Andre Drummond as the preseason Freshman/Newcomer of the Year ahead of Davis,[65][66] although Davis was the only freshman on the ESPN 10-man preseason team.[67] Davis only received one vote for the Associated Press preseason All-America team.[68]After most of the pre-conference schedule but before the 2011–12 Southeastern Conference men's basketball schedule, Davis' teammate, Michael Kidd-Gilchrist was mentioned as a possible Southeastern Conference Men's Basketball Player of the Year.[69]However, after less than a month of Southeastern Conference play, Davis was not only being mentioned as conference player of the year, but also National Player of the Year.[70] By mid February, he was considered a National Player of the Year front-runner with his primary competition coming from Thomas Robinson of Kansas.[71] As the season progressed, he continued to battle Robinson while developing a college level offensive game.[72][73] Davis averaged a double double and 6.5 blocks in the two games (November 15, 2011 and April 2, 2012) in which the two players opposed each other, both on neutral courts.[74][74] Davis led the Wildcats to a perfect 16–0 record in conference play en route to the SEC conference regular season championship.[75]Davis finished the year with averages of 14.2 points per game, 10.4 rebounds per game, 4.7 blocks per game and a Field goal percentage of 62.3%.[76] The Wildcats entered the SEC Tournament as heavy favorites and defeated LSU and Florida before losing to the Vanderbilt Commodores in the championship game.[75] Despite the loss, the Wildcats earned the number one overall seed in the 2012 NCAA Men's Division I Basketball Tournament.[77] In the Wildcats' six NCAA Tournament games, Davis averaged 15.2 points, 11.2 rebounds, and 4.6 blocks per game, and led the team to its eighth NCAA Championship.[78][79]WatchlistsOn October 20, 2011, Davis was one of three Kentucky Wildcats named to the 12-man preseason watchlist for the 2012 Wayman Tisdale Award along with Kidd-Gilchrist, and Teague.[80] On November 7, 2011, he was selectedto the 50-man preseason 2012 Naismith College Player of the Year Award watchlist by the Atlanta Tipoff Club along with three Kentucky teammates (Jones, Kidd-Gilchrist, and Teague).[81] Davis was included on the 25-man John R. Wooden Award Midseason list on January 17.[82]On February 6, Davis and Kidd-Gilchrist were both included on the 20-player 2012 Oscar Robertson Trophy midseason watch list.[83] Davis and Kidd-Gilchrist were both among the five March 1 finalists for the 2012 Wayman Tisdale Award, which the United States Basketball Writers Association(USBWA) will award to the nation's top freshman player via a March 30 announcement and April 16 presentation.[84] On March 1, Davis and Kidd-Gilchrist were both named to the 30-player midseason Naismith watchlist.[85] On March 6, Davis and Kidd-Gilchrist moved on to the final 15 nominees for the Wooden Award.[86] As a USBWA first team All-American selection on March 12, he became one of five finalists for the Robertson Trophy.[87]On March 19, he became one of four finalists for the Naismith Award.[88] Davis was named as one of 10 finalists for the Wooden Award, a designation termed as WoodenAll-American.[89]Honors and awardsNational外部图片链接Davis was named the 2012 Sporting News Men's College Basketball Player of the Year.[90] On March 19, he won the U.S.Basketball Writers Association's (USBWA) Robertson trophy.[91][92] TheCommonwealth Athletic Club ofKentucky named Davis the Adolph Rupp Trophy winner on March 22.[93]recognized Davis as their national player of the year.[94]On March 30, he became the second freshman (Kevin Durant) to win the Associated Press College Basketball Player of the Year.[95]On March 31, he won the John R. Wooden Award.[96] The following day he wonthe Naismith College Player of theYear.[97] He was Kentucky's first Naismith winner and the first from the SEC in 42 years (Pete Maravich).[98]Davis was named to the 2012 Sporting News All-American first team.[90] He was also named first team All-American by the United States Basketball Writers Association.[87] On March 20, the National Association of Basketball Coaches(NABC) chose him as a first team All-American.[99]Daviswas a first team All-American.[94] Davis was named a first team Associated Press All-American, making him a unanimous first team All-American selection.[100]During the 2012 NCAA Tournament, Davis was selected to the NCAA South Regional All-Tournament Team.[101] Then, in the 2012 NCAA Men's DivisionI Basketball Tournament final four, he posted 18 points, 14 rebounds and5 blocks against Louisville.[102] In the championship game, he had 16 rebounds, 6 blocks, 5 assists, 3 steals and 6 points against Kansas.[74] He won the NCAA Basketball Tournament Most Outstanding Player and was selected to that All-Tournament team.[103] He was the fourth freshman to win the Most Outstanding Player award.[104]Davis was named the USBWA National Freshman of the Year.[105]He was selected by the USBWA as the Player of the Year for its 10-man 2011–12 Men's All-District IV (Kentucky, Tennessee, Mississippi, Alabama, Georgia, Florida) Team.[106]Davis was a first team selection to the NABC Division I All‐District 21 team on March 14.[107]On April 1, he was also awarded the Pete Newell Big Man Award and the NABC Defensive Player of the Year.[108] recognized him with the Lefty Driesell Award as Defensive Player of the Year and the Kyle Macy Award as Freshman of the Year.[109]ConferenceDavis as a WildcatDavis twice earned SEC Player of the Week (POTW) honors (Week of February 6 and 27, 2012)[110][111] and four times, when he was not Player of the Week,he earned SEC Freshman of the Week (FOTW) honors (11/14/2011, 1/2/2012, 1/16/2012, and 3/5/2012).[112][113][114][115] He earned his first FOTW honor for debuting with a double double, including 23 points, 10 rebounds, 5 blocks and 3 assists against Marist on November 11, 2011.[112][116] Only Jones and Sam Bowie had previously had 20 or more points and 10 or more rebounds in their Kentucky Freshman debut.[117] His second FOTW came in a week in which he averaged 14.0 points, 11.5 rebounds, six blocks, 1.5 steals and 1 assist in wins over Lamar and fourth-rated Louisville.[113][118][119]His third FOTW award came when he averaged 16 points, 7 rebounds, 4 blocks, 2.5 steals and 2 assists in wins at Auburn and at Tennessee where both his point totals were game highs.[114][120][121] He earned his fourth FOTW when he averaged 15.5 points, 10 rebounds and 4 blocks in wins over Georgia and at Florida.[115][122][123] He earned his first POTW recognition for averaging 20 points, eight rebounds, 7.5 blocks and 2 assists in wins over Tennessee and at South Carolina.[110][124][125] For Davis' second POTW he posted a pair of double doubles to average 20.5 points, 11 rebounds, 3.5 blocks and two steals in wins at Mississippi State and over Vanderbilt.[111][126][127] The February 25 win against Vanderbilt clinched the 2011–12 SEC championship for Kentucky as Davis tallied a career-high 28 points as well as 11 rebounds and 5 blocked shots.[128]ESPN's Andy Katz described his SEC title-clinching performance as the most complete performance of his career.[73]He was also selected as the SEC Player of the Year, SEC Freshman of the Year, SEC Defensive Player of the Year and a first team All-SEC honoree.[129] The SEC awards were selected by the league's 12 coaches who were not permitted to vote for their own players. Thus, no awards are unanimous.[130] Sporting News also selected him as Freshman and Player of the Year for the SEC.[131]Also, the Associated Press selected him as Player and Newcomer of the Year for the SEC as well as an All-SEC performer.[132]Following the 2012 SEC tournament, he was selected to the SEC All-Tournament Team.[133]RecordsDuring the 2011–12 NCAA Division I men's basketball season, Davis blocked more shots per game than most Division I men's teams.[37][134]In the January 17 contest against Arkansas, Davis set the Kentucky men's basketball record for single-season blocked shots surpassing Melvin Turpin and Andre Riddick, who each had 83. In the game, he established a career high with 27 points and added 14 rebounds and 5 blocked shots.[135] On February 4, against South Carolina, Davis established the SEC freshman record with 116 blocks surpassing Shaquille O'Neal's total set for LSU.[110]One of the most notable blocks of the season was a block of John Henson with four seconds left to preserve a 73–72 victory when number one Kentucky hostednumber five North Carolina on December 3.[136][137] On March 15, Davis established a Kentucky single-game record for the NCAA Men's Division I Basketball Tournament by blocking 7 against Western Kentucky.[138]On March 25, Davis established the SEC single-season blocked shots record in the NCAA Tournament South Regional Championship game victory over Baylor,[101] surpassing Jarvis Varnado's total of 169.[139]On March 31, he tied DeMarcus Cousins with 20 double doubles for the Kentucky freshman-season record.[140] He also surpassed Cousins' Kentucky freshman rebounds record of 374 with 415 rebounds.[141][142][143] With six blocks in the championship game, he achieved a total of 186 for the season, surpassing Hassan Whiteside's 2010 total of 182, to set an NCAA Division I freshman record. This also tied the NCAA Men's Division I Basketball Championship Game record for blocks established by Joakim Noah in the 2006 NCAA Men's Division I Basketball Tournament.[144] Starting in the championship game gave him a total of 40 starts for the season, which tied Kentucky's single-season record along with teammate Marquis Teague.[144]Professional careerDavis and the entire national championship team starting five, which was composed of Davis, fellow freshmen Kidd-Gilchrist and Teague, and sophomores Jones and Doron Lamb, declared for the 2012 NBA Draft.[145] At the 2012 NBA Scouting Combine, Davis measured at 6英尺9.25英寸（2.06米）, 221.8磅（100.6千克） and had the second longest wingspan—7英尺5.5英寸（2.27米） of any player participating.[146]On June 28, the New Orleans Hornets selected Davis first overall.[147] Davis became the fifth Chicago-area first overall selection following Cazzie Russell (1966), LaRue Martin (1972), Mark Aguirre (1981) and Derrick Rose (2008).[148]On July 24, 2012, Davis signed a three-year $16 million guaranteed contract with the Hornets as prescribed by the NBA's collective bargaining agreement.[149]International playOn May 2, 2012, following a rash of injuries to players who had been on the 20-man Team USA basketball roster in January (notably center Dwight Howard), Davis was named as one of the finalists for the 2012 Olympic basketball team. Davis, along with Greg Monroe, was under consideration to fill the vacancy at center resulting from Howard's injury. Davis would be the first American player since Emeka Okafor (2004) to have competed in the Olympics without any prior NBA experience.[150] By the beginning of July, he was one of six players (along with Blake Griffin, James Harden,Rudy Gay, Andre Iguodala and Eric Gordon) competing for the final three roster spots, according to USA Basketball director Jerry Colangelo.[151] Tyson Chandler, Kevin Love, Griffin and Davis were the only true post players among the final 15.[151] It was reported that Davis "suffered a severely sprained ankle in a workout" on June 30 and "almost assuredly [would] bypass a chance to play for Team USA [that] summer in the London Olympics."[152]On July 12, 2012, however, he was selected for the 2012 USA men's basketball roster after Blake Griffin suffered a knee injury to the same knee he injured in the 2012 NBA Playoffs.[153]Personal lifeDavis is the son of Anthony Davis, Sr.[20]Davis, Sr. is 6英尺3英寸（1.91米） and his mother, Erainer, is 6英尺1英寸（1.85米）.[154]He has a twin sister, Antoinette and an older sister, Iesha who plays basketball at Daley College.[4][154]He has cousins named Jarvis, Marshaun and Keith Chamberlain. Keith was an expatriate professional basketball player in Germany and their father, Keith Sr., served as Davis' elementary school athletic director.[8]On June 15, 2012, he signed with Arn Tellem and the Wasserman Media Group as his agent s.[155] Davis trademarked his unibrow sayings "Fear The Brow" and "Raise The Brow" in June 2012.[156][157]。

键合金丝概要

键合金丝概况一、简要说明：1、键合金丝概念以及其应用键合是集成电路生产中的一步重要工序,是把电路芯片与引线框架连接起来的操作。

键合丝是半导体器件和集成电路组装时为使芯片内电路的输入/ 输出键合点与引线框架的内接触点之间实现电气链接而使用的微细金属丝内引线。

键合效果的好坏直接影响集成电路的性能。

键合丝是整体IC封装材料市场五大类基本材料之一，是一种具备优异电器、导热、机械性能并且化学稳定性极好的内引线材料,是制造集成电路及分立器件的重要结构材料,键合丝主要用于各种电子元器件,如二极管、三极管、集成电路等。

下面的截面示意图描绘了半导体元件中各部分间的结构关系：2、性能要求以及测试方法标准键合金丝类型、状态、各项要求与其中部分测试方法、包装等均在中华人民共和国国家标准《GB/T 8750-2007 半导体器件用键合金丝》列出：图2 国家标准《GB/T 8750-2007 半导体器件用键合金丝》Pull strength: 抗拉强度，强度越高，可以实现更快速的键合FAB formation：自由空气球形球质量Gas cost: 保护气体成本，FAB形成时是否需要保护气体以及气体成本，Au丝不要保护气HTS：high temperature storage 性能，焊点可靠性Storage：库存成本Price：价格1 bond margin: 第一焊点——球焊点形成后，边缘直径，对于焊盘间距的设计非常重要Squashed ball deviation: FAB在超声和压力的作用下与芯片上焊盘键合后，变成的扁平球（Squashed ball），在进行大量键合后Squashed ball 尺寸的分散度，对于实际生产的质量控制非常关键3、客户以及相关信息表1 2010年键合丝用户及相关信息列表4、竞争对手以及行业标杆1.贺利氏：目前世界最大的键合金丝生产厂家，在中国有常熟和招远两个工厂，键合丝业务涉及金丝、铜丝、铝丝。

铝的剪切模量

铝的剪切模量（Shear modulus），又称剪切弹性模量，是描述材料抵抗剪切应力的特
性参数，通常用符号G表示。

它表示单轴剪切应力作用下，材料单位面积的剪切应变，单位为帕斯卡（Pa）或吉帕（GPa）等。

铝的剪切模量与其弹性模量（Young's modulus）和泊松比（Poisson's ratio）之间存在一定的关系。

在理想情况下，可通过这两个参数计算得到铝的剪切模量，并由此估算铝
的剪切强度。

根据实验测量结果和计算，一般认为铝的剪切模量在26-35 GPa之间。

具体数值还取
决于铝的品种、纯度、状态等因素。

在工程设计和研究中，通常采用标准值作为参考，如GB/T 2694-2010《金属材料的拉伸、压缩和弯曲试验方法》中规定的铝的剪切模量
为26.5GPa。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211Chapter 13 Transverse Shear 1. 2. 3. 4.上海交通大学SJTUCHAPTER OUTLINEShear in Straight Members The Shear Formula Shear Stresses in Beams Shear Flow in Built-up MembersChapter 13上海交通大学SJTUTransverse ShearIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR IN STRAIGHT MEMBERSShear V is the result of a transverse shear-stress distribution that acts over the beam’s x-section. Due to complementary property of shear, associated longitudinal shear stresses also act along longitudinal planes of beamSHEAR IN STRAIGHT MEMBERSAs shown below, if top and bottom surfaces of each board are smooth and not bonded together, then application of load P will cause the boards to slide relative to one another.上海交通大学SJTU上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR IN STRAIGHT MEMBERSHowever, if boards are bonded together, longitudinal shear stresses will develop and shear strains will distort x-section in a rather complex manner上海交通大学SJTUSHEAR IN STRAIGHT MEMBERSAs shown, when shear V is applied, the non-uniform shear-strain distribution over x-section will cause it to warp, i.e., not remain plane.上海交通大学SJTU1Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR IN STRAIGHT MEMBERSRecall that the flexure formula assumes that xsections must remain plane and perpendicular to longitudinal axis of beam after deformationSHEAR IN STRAIGHT MEMBERSThis is violated when beam is subjected to both bending and shear, we assume the warping is so small that it can be neglected. This is true for a slender beam (small depth compared with its length) For transverse shear, shear-strain distribution throughout the depth of a beam cannot be easily expressed mathematically上海交通大学SJTU上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR IN STRAIGHT MEMBERSThus, we need to develop the formula for shear stress is indirectly using the flexure formula and relationship between moment and shear (V = dM/dx)上海交通大学SJTUTHE SHEAR FORMULA上海交通大学SJTUV, V + dV, w(x)??Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211THE SHEAR FORMULAConsider horizontal force equilibrium of upper portion of element dx with longitudinal shear stress τ uniformly acts over its bottom face with width t, using flexure formula and V = dM/dx, we get0A′ 海交M + d M ) y d A − ( M ) y d A − τ ( td x ) = 0 ( ∫通 I ∫′ I A′ A 大 dM ( ) ∫ y d A = τ ( td x ) 学I A ′ A′∑F =0 σ ∫上 ′d A − ∫ σ d A − τ ( td x ) =xQ = ∫ y dA = y’A’A’∴τ =SJTU1 dM 1 ( ) ydA = V I t d x ∫′ It Aτ = VQ It上海交通大学SJTUτ=VQ It∫ydAA′2Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211THE SHEAR FORMULAV = internal resultant shear force, determined from method of sections and equations of equilibrium τ = shear stress in member at the point located a distance y’ from the neutral axis. Assumed to be constant and therefore averaged across the width t of member VQ ItTHE SHEAR FORMULAI = moment of inertia of entire x-sectional area computed about the neutral axis t = width of the member’s x-sectional area, measured at the point where τ is to be determined上海交通大学SJTU上海交通大学SJTUτ=Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211THE SHEAR FORMULAQ = ∫A’ y dA’ = y’A’, where A’ is the top (or bottom) portion of member’s x-sectional area, defined from section where t is measured, and y’ is distance of centroid of A’, measured from neutral axis上海交通大学SJTUTHE SHEAR FORMULAThe equation derived is called the shear formula Since Eqn is derived indirectly from the flexure formula, the material must behave in a linear-elastic manner and have a modulus of elasticity that is the same in tension and in compression上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSRectangular x-section Consider beam to have rectangular x-section of width b and height h as shown. Distribution of shear stress throughout x-section can be determined by computing shear stress at arbitrary height 上 y from neutral axis (note y and y’) 海交通大学SJTUSHEAR STRESSES IN BEAMSRectangular x-section After deriving Q and applying the shear formula, we have 1 h2 VQ 6V h2 2 Q = ( − y2 )b τ = τ= ( −y ) 2 4 It bh3 4上海交通大学SJTUh ( − y) h h 1 h Q = ( − y) ⋅ b ⋅ ( y + 2 ) = ( − y) ⋅ b ⋅ ⋅ ( + y ) 2 2 2 2 2Q=1 h2 2 ( − y )b 2 43Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSRectangular x-section • Eq indicates that shear-stress distribution over xsection is parabolic. 6V h2 2 τ= ( −y ) bh3 4上海交通大学SJTUSHEAR STRESSES IN BEAMSRectangular x-section At y = 0, we haveτmax = 1.5V A上 • By comparison, τmax is 50% 海 greater than the average shear 交 stress determined from 通大 τavg = V/A. 学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSWide-flange beam A wide-flange beam consists of two (wide) “flanges” and a “web”.上海交通大学SJTUSHEAR STRESSES IN BEAMSWide-flange beam Using analysis similar to a rectangular x-section, the shear stress distribution acting over x-section is shown上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSWide-flange beam The shear-stress distribution also varies parabolically over beam’s depth Note there is a jump in shear stress at the flange-web junction since x-sectional thickness changes at this point 上海 The web carries significantly 交 more shear force than the flanges通大学SJTUSHEAR STRESSES IN BEAMSLimitations on use of shear formula One major assumption in the development of the shear formula is that shear stress is uniformly distributed over width t at section where shear stress is to be determined上海交通大学SJTU4Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSLimitations on use of shear formula By comparison with exact mathematical analysis based on theory of elasticity, the magnitude difference of τ’max whose exact value occurs at edges of x-section can reach 40% with the ratio b/h of 2, but 3% with the ratio b/h of 0.5 上海交通大学SJTUSHEAR STRESSES IN BEAMSLimitations on use of shear formula This is especially so for the flange of a wide-flange beam and it is intolerable to use the shear formula to determine the shear stress at the flange上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSLimitations on use of shear formula The shear formula will also give inaccurate results for the shear stress at the flange-web junction of a wideflange beam, since this is a point of sudden x-sectional change (stress concentration occurs here)SHEAR STRESSES IN BEAMSLimitations on use of shear formula Furthermore, inner regions of flanges are free boundaries, thus shear stress at these boundaries should be zero However, shear formula calculated at these points will 上 not be zero 海交通大学SJTU上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSLimitations on use of shear formula at a point on an inclined boundary上海交通大学SJTU?V上海交通大学SJTU5Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSProcedure for analysis Internal shear Section member perpendicular to its axis at the point where shear stress is to be determined Obtain internal shear V at the section 上海交通大学SJTUSHEAR STRESSES IN BEAMSProcedure for analysis Section properties Determine location of neutral axis, and determine the moment of inertia I of entire x-sectional area about the neutral axis 上 Pass an imaginary horizontal section through the point 海交 where the shear stress is to be determined通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSProcedure for analysis Section properties Measure the width t of the area at this section Portion of area lying either above or below this section is A’. 上海 Determine Q either by integration, Q = ∫A’ y dA’, or 交 by using Q = y’A’.通大学SHEAR STRESSES IN BEAMSProcedure for analysis Section properties Here, y’ is the distance to centroid of A’, measured from the neutral axis. (TIP: A’ is the portion of the member’s x-sectional area being “held onto the member” by the 上 longitudinal shear stresses.) 海交通大学SJTUSJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSProcedure for analysis Shear stress Using consistent set of units, substitute data into the shear formula and compute shear stress τ Suggest that proper direction of transverse shear stress 上 be established on a volume element of material located 海交 at the point where it is computed通大学SJTUSHEAR STRESSES IN BEAMSProcedure for analysis Shear stress τ acts on the x-section in the same direction as V. From this, corresponding shear stresses acting on the three other planes of element can be established上海交通大学SJTU6Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE 13.3Beam shown is made from two boards. Determine the maximum shear stress in the glue necessary to hold the boards together along the seams where they are joined. Supports at B and C exert only vertical reactions on the beam.EXAMPLE 13.3 (Solution)Internal shear Support reactions and shear diagram for beam are shown below. Maximum shear in the beam is 19.5 kN.上海交通大学SJTU上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE 13.3 (Solution)Section properties The centroid and therefore the neutral axis will be determined from the reference axis placed at bottom of the x-sectional area. Working in units of meters, we have Σ yA 上 y= = ... = 0.120 m ΣA 海交通大学SJTUEXAMPLE 13.3 (Solution)Section properties Thus, the moment of inertia, computed about the neutral axis is I = ... = 27.0(10-6) m4上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE 13.3 (Solution)Section properties The top board (flange) is being held onto the bottom board (web) by the glue, which is applied over the thickness t = 0.03m. Consequently A’ is defined as the area of the top board, we have Q = y’A’ = [(0.180 m − 0.015 m − 0.120 m] (0.03 m)(0.150 m) Q = 0.2025(10-3) m3EXAMPLE 13.3 (Solution)Shear stress Using above data, and applying shear formula yields VQ = ... = 4.88 MPa It Shear stress acting at top of bottom board is shown here. It is the glue’s resistance to this lateral or horizontal shear stress that is necessary to hold the boards from slipping at support C.τmax =上海交通大学SJTU上海交通大学SJTU7Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR FLOW IN BUILT-UP MEMBERS上海交通大学SJTU上海交通大学SJTUOccasionally, in engineering practice, members are “built-up” from several composite parts in order to achieve a greater resistance to loads, some examples are shown.Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR FLOW IN BUILT-UP MEMBERSSHEAR FLOW IN BUILT-UP MEMBERSThis loading, measured as a force per unit length, is referred to as the shear flow q. Magnitude of shear flow along any longitudinal section of a beam can be obtained using similar development method for finding the shear stress in the beam上海交通大学SJTUIf loads cause members to bend, fasteners such as nails, bolts or glue may be needed to keep component parts from sliding relative to one another. To design the fasteners, we need to know the shear force resisted by fastener along member’s length上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211Magnitude of shear flow along any longitudinal section of a beamSHEAR FLOW IN BUILT-UP MEMBERSThus shear flow is q = VQ/I∑ Fx = 0A′∫ σ ′dA − ∫ σ dA − τ (tdx) = 0A′1 dM ⎞ 1 ( ) ∫ ydA = VQ ydA ∴τ = ⎛ q= ⎜ ⎟ ydA = V ∫ It ⎝ dx ⎠∫′ ′ It A′ I I A ASJTU上M + dM M ( ) ydA − ( ) ydA − τ (tdx ) = 0 海 I I A′ A′ 交 dM 通 ( ) ydA = τ (tdx ) 大 I A′ 学∫∫q = shear flow, measured as a force per unit length along the beam V = internal resultant shear force, determined from 上 method of sections and equations of equilibrium海交通大学∫SJTU8Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR FLOW IN BUILT-UP MEMBERSThus shear flow is q = VQ/ISHEAR FLOW IN BUILT-UP MEMBERSNote that the fasteners in (a) and (b) supports the calculated value of q And in (c) each fastener supports q/2 In (d) each fastener supports q/3上海交通大学SJTU上海交通大学SJTUI = moment of inertia of entire xsectional area computed about the neutral axis Q = ∫A’ y dA’ = y’A’, where A’ is the x-sectional area of segment connected to beam at juncture where shear flow is to be calculated, and y’ is distance from neutral axis to centroid of A’Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211SHEAR FLOW IN BUILT-UP MEMBERSIMPORTANT Shear flow is a measure of force per unit length along a longitudinal axis of a beam. This value is found from the shear formula and is used to determine the shear force developed in fasteners and 上 glue that holds the various segments of a beam together 海交通大学SJTUEXAMPLE 13.4Beam below is constructed from 4 boards glued together. It is subjected to a shear of V = 850 kN. Determine the shear flow at B and C that must be resisted by the glue.上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE 13.4 (Solution)Section properties Neutral axis (centroid) is located from bottom of the beam. Working in units of meters, we have上海交通大学SJTUEXAMPLE 13.4 (Solution)Section properties Since the glue at B and B’ holds the top board to the beam, we have QB = y’B A’B = [0.305 m − 0.1968 m](0.250 m)(0.01 m) -3 3 上 QB = 0.270(10 ) m海交通大学SJTUy=ΣyA = ... = 0.1968 m ΣyMoment of inertia about neutral axis is I = ... = 87.52(10-6) m4Likewise, glue at C and C’ holds inner board to beam, so QC = y’C A’C = ... = 0.01025(10-3) m39Introduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE 13.4 (Solution)Shear flow For B and B’, we have q’B = VQB /I = [850 kN(0.270(10-3) m3]/87.52(10-6) m4 q’B = 2.62 MN/m上海交通大学SJTUEXAMPLE 13.4 (Solution)Shear flow Similarly, for C and C’, q’C = VQC /I = [850 kN(0.0125(10-3) m3]/87.52(10-6) m4 q’C = 0.0995 MN/m上海交通大学SJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211EXAMPLE13.4 (Solution)Shear flow Since two seams are used to secure each board, the glue per meter length of beam at each seam must be strong enough to resist one-half of each calculated value of q’. Thus qB = 1.31 MN/m qC = 0.0498 MN/mREADING QUIZ1) Which of the following statement is not true? A)Shear stresses cause warping of cross section B)Warping effect is negligible for slender beams C)“Plane section remains plane” is valid for bending of 上 deep beam 海 D)Shear forces in beams cause non-linear shear-strain 交 distributions over the cross section通大学上海交通大学SJTUSJTUIntroduction to Solid Mechanics-Vm211Introduction to Solid Mechanics-Vm211APPLICATIONSHome Work Due Nov. 30, 201013-9， 13-20,上海交通大学SJTU上海交通大学SJTU13-28， 13-36.10SJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTShear forces in beams cause non-linear shear-strain distributions over the x-section, causing it to warpSJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTDue to complementary property of shear stress, the shear stress developed in a beam acts on both the x-section and on longitudinal planesSJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTThe shear formula was derived by consideringhorizontal force equilibrium of longitudinal shear stress and bending-stress distributions acting on a portion of a differential segment of the beam (V = dM/dx )SJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTThe shear formula is to be used on straight prismatic members made of homogeneous material that has linear-elastic behavior. Also, internal resultant shear force must be directed along an axis of symmetry for x-sectional area.SJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTFor beam having rectangular x-section, shear stress varies parabolically with depth.For beam having rectangular x-section, maximum shear stress is along neutral axis SJTU上海交通大学Introduction to Solid Mechanics-Vm211SHEAR STRESSES IN BEAMSIMPORTANTShear formula should not be used to determine shear stress on x-sections that are short or flat, or at points of sudden x-sectional changes, or at a point on an inclined boundary.Instead, for these cases the shear stress should be determined using more advanced methods based on the theory of elasticity.SJTU上海交通大学Introduction to Solid Mechanics-Vm211CHAPTER REVIEWTransverse shear stress in beams is determined indirectly by using the flexure formula and the relationship between moment and shear(V = dM/dx ). This results in the shear formula τ= VQ/It .SJTU上海交通大学Introduction to Solid Mechanics-Vm211CHAPTER REVIEWIn particular, the value for Q is the moment of the area A’about the neutral axis. This area is the portion of the x-sectional area that is “held on”to the beam above the thickness t where τis to be determinedSJTU上海交通大学Introduction to Solid Mechanics-Vm211CHAPTER REVIEWIf the beam has a rectangular x-section, then the shear-stress distribution will be parabolic, obtaining a maximum value at the neutral axisSJTU上海交通大学Introduction to Solid Mechanics-Vm211CHAPTER REVIEWFasteners, glues, or welds are used to connect thecomposite parts of a “built-up”section. The strength of these fasteners is determined from the shear flow, or force per unit length, that must be carried by the beam; q = VQ/ISJTU上海交通大学Introduction to Solid Mechanics-Vm211READING QUIZ2) Which of the following statement is not true?The shear formula should not be used to determine the shear stressA)On cross sections that are short or flatB)At points of sudden cross-sectional changes C)At a point on an inclined boundary D)None of the above。