dynamic response of suspension bridge(悬索桥动力特性研究)
轴箱内置和外置高速转向架的动力学性能对比
第18卷第3期铁道科学与工程学报Volume18Number3 2021年3月Journal of Railway Science and Engineering March2021 DOI:10.19713/ki.43−1423/u.T20200385轴箱内置和外置高速转向架的动力学性能对比张隶新1,2(1.中车唐山机车车辆有限公司,河北唐山063035;2.河北省轨道车辆转向架技术创新中心,河北唐山063035)摘要:根据悬挂系统的结构形式,转向架分为轴箱内置转向架和轴箱外置转向架。
相对于轴箱外置转向架,轴箱内置转向架结构紧凑、质量小,有利于降低轮轨磨耗和通过小半径曲线,具有良好的线路适应性。
针对时速350km/h货运动车组,考虑高铁线路和既有线路运行工况,通过动力学仿真软件SIMPACK计算车辆分别采用轴箱内置转向架和轴箱外置转向架的轮轨力和车轮磨耗,对比分析2种转向架的安全性、平稳性以及线路适应性。
研究结果表明:在保证2种转向架具有相同蛇行运动稳定性即临界速度的前提下,与轴箱外置转向架相比,内置转向架的轮轨力降低20%以上,车轮磨耗量和踏面磨耗深度降低30%以上,充分体现了轴箱内置转向架的动力学性能优越性。
关键词:高速列车;轴箱内置转向架;动力学;轮轨力;车轮磨耗中图分类号:U27文献标志码:A开放科学(资源服务)标识码(OSID)文章编号:1672−7029(2021)03−0581−07Dynamics analysis of high-speed railway bogies withinner bearing and outer bearing suspensionsZHANG Lixin1,2(1.CRRC Tangshan Co.,Ltd.,Tangshan063035,China;2.Hebei Railway Vehicle Bogie Technology Innovation Center,Tangshan063035,China)Abstract:According to the structure types of vehicle suspension system,bogie is divided into the inner bearing bogie and outer bearing pared with the outer bearing bogie,the inner bearing bogie has a more compact structure and little mass,which is conducive to pass small radius curved track and reduce wheel wear. The inner bearing bogie has better running adaptability.In this paper,the high-speed EMU at the speed of350 km/h was taken as the research object.Considering the operating conditions of high-speed railway lines and existing lines,the wheel-rail force and wheel wear of the inner bearing bogie and outer bearing bogie have been calculated in dynamics simulation software SIMPACK.We have also compared the safety,stationarity and running adaptability performance of the two bogies.As the results shows,under the premise that the two bogies have the same hunting stability,that is,the critical speed.The wheel-rail force of the inner bearing bogie is reduced by more than20%compared with the outer bearing bogie,and the wheel wear and tread wear depth are收稿日期:2020−05−09基金项目:国家重点研发计划资助项目(2018YFB1201702)通信作者:张隶新(1974−),男,河北唐山人,高级工程师,从事转向架系统技术研发;E−mail:**************************铁道科学与工程学报2021年3月582reduced by more than30%.The results fully demonstrate the dynamic performance superiority of the inner bearing bogie.Key words:high-speed train;inner bearing bogie;dynamic;wheel-rail force;wheel wear高速列车的动力学性能决定了车辆的最高运行速度、运行安全性和运行品质。
基于动力松弛法的悬索桥主缆找形方法分析与工程实践研究
基于动力松弛法的悬索桥主缆找形方法分析与工程实践研究杨华;王英飞【摘要】在悬索桥主缆找形计算分析中,基于动力计算理论引用动力松弛法,为悬索桥找形提供新的思路.根据悬索桥主缆的受力特征,给出了动力松弛发在悬索桥主缆找形计算方式,并以某工程实例为空为算例对象,通过与传统解析算法和迭代算法在悬索桥找形中的应用,对比分析了动力松弛法理论在悬索桥主缆找形计算结果精度和计算速度.研究结果表明:动力松弛法通过对研究体系进行时空的离散化来将静力学问题转化为动力学求解,计算收敛速度要明显高于抛物线法和节点法;对主缆线形内力的计算结果与有限元迭代算法误差在5%范围内,吻合度较高.基于动力松弛法在悬索桥主缆找形中的运用,具有计算稳定,收敛性好的优势,能有效解决悬索桥主缆选形等几何非线性问题中,满足工程实用需求.%in this paper,the dynamic relaxation method based on dynamic calculation theory is used to provide a new idea for the shape of suspension bridge.According to the stress characteristics of suspension bridge main cable,dynamic relaxation is over the suspension bridge main cable is given for calculation,and with a project example is empty for example object,with traditional parsing algorithm and iteration algorithm in the application of suspension bridge for shape,contrast analysis of the dynamic relaxation method theoretical calculation result in suspension bridge main cable shape precision and computing speed.Research results show that the dynamic relaxation method based on the research system for the discretization of space and time to dynamics statics problem can be converted to solving,the convergence speed significantly higher than the parabola method andnode method;The calculation results of the inner force of the main cable and the error of the finite element iteration algorithm are within 5%.Based on dynamic relaxation method in suspension bridge main cable shape,the application of calculation stability and convergence advantage,can effectively solve the suspension bridge main cable to choose the geometric nonlinear problem such as form,meet the demand of practical engineering.【期刊名称】《公路工程》【年(卷),期】2017(042)006【总页数】6页(P248-253)【关键词】悬索桥;动力松弛法;主缆找形【作者】杨华;王英飞【作者单位】中交铁道设计研究总院有限公司,北京 100000;中国公路工程咨询集团有限公司,北京100000【正文语种】中文【中图分类】U448.250 前言大跨度柔索结构被广泛应用于悬索桥的主缆结构中,而悬索桥的主缆选形问题一直是研究难点。
五峰山长江大桥主桥总体设计
桥梁建设2020年第50卷第6期(总第268期)Bridge Construction,Vol.50,No.6#2020(Totally No.268"文章编号!003—4722(2020)06—0001—07五峰山长江大桥主桥总体设计唐贺强,徐恭义,刘汉顺(中铁大桥勘测设计院集团有限公司,湖北武汉430056)摘要:连镇铁路五峰山长江大桥主桥为主跨1092m公铁两用钢桁梁悬索桥,按4线高速铁路+8车道高速公路设计,主缆跨度为(350+1092+350)m,加劲梁跨度为(84+84+1092 + 84+84)m$加劲梁采用大节段整体设计,由竖向、横向支座与纵向阻尼器支承,立面为华伦桁式,横断面为带副桁的直主桁形式,材质为Q370qE钢。
该桥采用双层桥面布置,上、下层桥面均为板桁结合正交异性整体桥面,顶板与U肋之间采用了双面焊全熔透焊接,铁路桥面道芹槽面板采用轧制不锈钢复合钢板。
主缆垂跨比1/10,直径1.3m,索股混编,采用钢结构锚固系统;索鞍为铸焊结合式,主索鞍纵向分3块制造$桥塔采用门式框架混凝土结构,塔顶设计为“五峰”造型,基袖采用桩基袖,其中南塔基袖为长短桩设计。
北锚碇采用大型沉井基袖,南锚碇采用不等深圆形地连墙基袖。
研究表明:大桥结构的静、动力性能满足高速列车行车的安全性与舒适性要求$关键词:公路铁路两用桥;悬索桥;总体布置;钢桁梁;主缆;锚碇;桥梁设计中图分类号:U44&25;U442.5文献标志码:AOverall Design of Main Bridge of WufengshanChangjiang River BridgeTANG He-qiang,XU Gong-yi,LIU Han-shun(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan430056,China)Abstract:The main bridge of Wufengshan Changjiang River Bridge on Lianyungang-Zhenjiang High-speed Railway is a steel truss girder suspension bridge with a main span of1092m,which is designed to accommodate four high-speed rail tracks and eight highway lanes.The main cable suspends threespans,comprisinglengthsof350,1092and350m,andthesuperstructurecontainsfive spansof84,84,1092,84and84m.Warrentrussescanbeseenfromtheelevationview,while thecrosssectionofthesti f eninggirderincorporatessubsidiarytrussesandthemembersoftrusses are straight.The trusses are made of Q370qE steel.The bridge has two floors formed of integral orthotropicplates.Thetopplateand U-ribsareweldedbydouble-sidedfu l penetration welding, andtheba l asttroughplatesintherailfloorare madeofro l edstainlesscompositesteelplates.The main cable,which is1.3m in diameter,with a sag-to-main span ratio of1/10,contains hybrid strandsandisanchoredbysteelanchorages.Thecablesaddletakesform bycastingandwelding# which wasdividedinto3blockslongitudina l yfortheeaseofmanufacturing.Thetowersthatare supported by pile foundations are concrete portal structures with"five peaks"crowns,and the founda0ionof0hesou0h0owercon0ainspileswihdi f eren0leng0hs.Thenor0hanchorageismoun0edon largecaissonfoundaion#while0hesou0hanchorageissea0edoncirclediaphragm wa l founda0ion that consists of walls with different depths.Studies reveal that the static and dynamic performance收稿日期:2020—06—02基金项目:中国铁路总公司科技研究幵发计划项目(2015G002—A)Project of Science and Technology Research and Development Program of China Railway Corporation(2015G002-A)作者简介:唐贺强,教授级高工,E-mail:tanghq@&研究方向:大跨度桥梁设计。
接触网弹性吊索参数对弓网动态性能影响
文章编号:0258-2724(2021)03-0659-07 DOI: 10.3969/j.issn.0258-2724.20190326接触网弹性吊索参数对弓网动态性能影响关金发 1,2,田志军 1,张学武1(1. 中铁第一勘测设计院集团有限公司,陕西 西安 710075;2. 西南交通大学电气工程学院,四川 成都 610031)摘 要:为确定不同速度等级接触网弹性吊索参数的优选值,利用有限单元法,建立了中国高速铁路250、350 km/h 两种速度等级的受电弓、接触网和弓网接触的动力学仿真模型,得到受电弓与接触网的动态性能指标,比较双弓作用下不同接触网弹性吊索截面积、张力和长度的弓网接触力数字特征和接触网定位点最大抬升. 研究结果表明:适应250 km/h 的O2-1型接触网弹性吊索宜选用线型为JTMH 35 mm 2、张力范围为(2.80 ± 0.10) kN ,长度为14 m 或18 m ;适应350 km/h 的京沪高速铁路接触网弹性吊索宜选用线型为JTMH 35 mm 2、张力范围为(3.50 ± 0.10) kN ,长度为18 m ;弹性吊索参数变化对前弓的接触力影响较小,对后弓的接触力影响显著;250 km/h 和350 km/h 下弹性吊索长度22 m 的定位点最大抬升分别是长度18 m 的111%和117%,弹性吊索长度的变化对定位点最大抬升影响显著.关键词:接触网;受电弓;弹性吊索;接触力;抬升中图分类号:N225.3 文献标志码:AInfluence of Catenary Stitch Wire Parameters on Dynamic Performance Between Pantograph and CatenaryGUAN Jinfa 1,2, TIAN Zhijun 1, ZHANG Xuewu1(1. China Railway First Survey & Design Institute Group Co.,Ltd.,Xi’an 710075,China; 2. School of Electrical Enginee-ring ,Southwest Jiaotong University ,Chengdu 610031,China)Abstract : In order to determine the optimal design values of the catenary stitch wire at different speed levels ,the dynamic simulation models of pantograph ,catenary and pantograph-catenary contact have been established by finite element method ,which correspond to the speed levels of 250 and 350 km/h for Chinese high-speed railways. The dynamic performance indexes of pantograph and catenary ,such as the section area ,statistics of contact force and the maximum uplift at supporting points have been obtained and compared ,with different cross-sectional areas ,tensions and length of the stitch wire under double pantographs. The results show that for the parameters of the stitch wire on O2-1 catenary ,JTMH 35 mm 2cross-section ,(2.80 ± 0.10) kN tension and 14 m or 18 m length at 250 km/h should be chosen ;for the parameters of stitch wire on Beijing−Shanghai high-speed catenary ,JTMH 35 mm 2cross-section ,(3.50 ± 0.10) kN tension and 18m length at 350 km/h. The change of stitch wire parameters has little influence on the contact force of the anterior pantograph ,but has a significant effect on that of the posterior pantograph. The maximum uplift at supporting points with the stitch wire length of 22 m is 111% at 250 km/h and 117% at 350 km/h of the stitch wire length of 18 m ,which means that the change of stitch wire length has a significant impact on the maximum uplift.Key words : catenary; pantograph; stitch wire; contact force; uplift收稿日期:2019-04-30 修回日期:2019-09-09 网络首发日期:2019-09-24基金项目:国家重点研发计划(2018YFC0808706);国家自然科学基金(U1534209))第一作者:关金发(1986—),男,讲师,博士,研究方向为受电弓与接触网动态仿真与测试,E-mail :*****************通信作者:田志军(1963—),男,教授级高工,硕士,研究方向为接触网工程设计,E-mail :****************引文格式:关金发,田志军,张学武. 接触网弹性吊索参数对弓网动态性能影响[J]. 西南交通大学学报,2021,56(3): 659-665.GUAN Jinfa , TIAN Zhijun , ZHANG Xuewu. Influence of catenary stitch wire parameters on dynamic performance between pantograph and catenary[J]. Journal of Southwest Jiaotong University , 2021, 56(3): 659-665.第 56 卷 第 3 期西 南 交 通 大 学 学 报Vol. 56 No. 32021 年 6 月JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITYJun. 2021高速运行的受电弓要求接触网的弹性尽可能均匀,通常用弹性不均匀度反映一跨内接触网的弹性均匀程度. 接触网弹性与线索截面、材料、张力、跨距、结构高度、预弛度、有无弹性吊索及弹性吊索参数有关[1]. 接触网弹性均匀程度是弓网稳定运行的主要条件,接触网弹性均匀程度越小,弓网运行越稳定[2]. 《高速铁路设计规范》(TB 10621—2004)[3]中提到当使用双弓运行时,较小的弹性不均匀度是弓网动态关系可以接受的前提保障之一,宜采用弹性链形悬挂. TB 10621《高速铁路设计规范条文说明》(TB 10621—2004)[4]中提出不同速度等级的推荐方案. 其中250 km/h等级分两种:O2-1悬挂系统中弹性吊索张力选用2.8~3.5 kN,O2-2悬挂系统中弹性吊索张力选用3.5 kN;O3-1悬挂系统中弹性吊索张力选用3.5 kN. 弹性吊索长度根据跨距和系统动态性能进行确定,一般为14~22 m[4]. 但调研相关标准并未给出弹性吊索参数的选取依据.为获取弹性吊索参数的合理范围,可利用弓网动态仿真技术,预测不同弹性吊索参数组合下的弓网动态性能. 文献[5-6]概述了弓网动态仿真建模的主要方法,并总结了十个国际上的弓网仿真程序的仿真效果;文献[7-9]分别研究了承力索张力、接触线弛度、表面不平顺和锚段关节对弓网动态性能的影响;文献[10-11]分别研究了受电弓、接触网空气动力对弓网动态性能的影响;文献[12-13]研究了双弓运行下弓间距对弓网动态性能的影响;文献[14]利用弓网动态仿真,建立单个DSA380型受电弓与德国Re330型弹性链形悬挂接触网的仿真模型,研究不同接触网参数对弓网动态性能的影响,并提出了Re330型接触网参数的选取范围,其中弹性吊索张力不小于3.5 kN,长度取16~18 m. Re330型接触网参数与中国高铁接触网参数有一定区别,且中国高铁较多使用双弓运行,后弓的弓网动态性能受到前弓的影响,双弓作用下不同弹性吊索参数对弓网动态性能的影响规律尚不明确.基于此,针对中国高铁典型接触网参数中的弹性吊索参数选取仍需进一步深入研究. 利用经工程验证的弓网仿真建模方法,建立不同速度等级的弓网动态仿真模型,分析双弓作用下弹性吊索参数对弓网动态性能影响,确定弓网动态性能较优的弹性吊索参数组合,从而减小弓网振动,延长设备寿命,为接触网系统设计提供参考依据.1 弓网动态仿真建模及模型参数利用文献[15]提出的经京津城际、京沪高铁实际测量数据验证过的受电弓与接触网动力学仿真建模方法,受电弓与接触网仿真模型采用有限单元法,弓网接触模型采用罚函数法,建立250 km/h和350 km/h两个速度等级的受电弓与接触网动态仿真模型.受电弓的动力仿真模型如图1所示,为三质量-刚度-阻尼归算质点模型. 图中:m3、m2、m1分别为弓头、上框架、下臂杆归算质量;c3、c2、c1分别为弓头、上框架、下臂杆归算阻尼;k3、k2、k1分别为弓头、上框架、下臂杆归算刚度;f c为弓网接触力;f0为静态接触力;y3、y2、y1分别为弓头、上框架、下臂杆归算坐标. 250 km/h线路的受电弓为DSA250型;350 km/h 线路的受电弓为DSA380型、SSS400+型和CX-NG 型. 其中DSA250型和DSA380型受电弓模型参数见表1[16].弓头归算上框架归算下臂杆归算f0m3c3c2c1k2k1k3ym2m1图 1 受电弓三质量块归算模型Fig. 1 Three-mass model of pantographs表 1 受电弓模型参数Tab. 1 Model parameters of pantograph受电弓m3/kg m2/kg m1/kg k3/(kN•m−1)k2/(kN•m−1)k1/(kN•m−1)c3/(N•s•m−1)c2/(N•s•m−1)c1/(N•s•m−1)DSA2507.51 5.85 4.648.38 6.200.080070.00 DSA3807.12 6.00 5.809.4314.1000070.00 660西 南 交 通 大 学 学 报第 56 卷不同运行速度下空气对受电弓产生一定的动态升力,以标准EN 50367[17]中提到的受电弓平均抬升力目标曲线为参考依据. 交流受电弓速度大于200 km/h 的最大平均抬升力为(70 + 0.000 97v 2) N ,(v 为运行速度,km/h ). 选用最大平均抬升力曲线作为计算的平均抬升力. 考虑8辆编组列车重联或16辆编组动车组,双弓运行,弓间距取200 m.标准TB 10621[4]中对接触网悬挂系统主要设计参数有所规定,250 km/h 线路以O2-1中接触网为例,350 km/h 线路以O3-1中京沪高铁接触网为例,其悬挂参数如表2所示. 根据接触网的建模方法及相关参数,建立接触网的仿真模型,如图2所示.表 2 接触网设计参数Tab. 2 Catenary design parameters接触网标称跨距/m 承力索线型接触线线型承力索单位长度质量/(kg•m −1)接触线单位长度质量/(kg•m −1)承力索张力/kN接触线张力/kN 结构高度/m 弹性吊索长度/mO2-1型60JTMH 95 mm 2CTMH120 mm 20.849 1.08215≥ 15.01.618京沪高速50JTMH 120 mm 2CTMH 150 mm2 1.065 1.3502031.5 1.618接触网弹性吊索线型弹性吊索单位长度质量/(kg•m −1)弹性吊索张力/kN 吊弦间隔/m 吊弦数量/组拉出值/m 跨距数量/跨分析区间/m O2-1型JTMH35 mm 20.311 2.80~3.508~1260.312240~960京沪高速JTMH35 mm 20.311 3.508~1250.212200~800xy O 图 2 接触网仿真模型Fig. 2 Catenary simulation model利用罚函数解决弓网接触问题,令接触线单元i −j 与质量点m 3的垂直方向渗透位移为ξ,假设质量点m 3在单元i −j 上方,ξ为正值,此时为接触状态,反之质量点m 3在单元i −j 下方,ξ为负值,此时为分离状态,见图3.图 3 弓网接触模型Fig. 3 Pantograph-catenary contact model当分离状态下接触刚度k c 为0. 当接触状态下k 为一正常数. 接触力为式中:t 为时间;参考EN 50367[17],k c 取50 kN/m.表2接触网参数中的O2-1接触线张力尚不确定,若采用15 kN ,利用接触网仿真建模方法,建立O2-1接触网的仿真模型,以70 N 的静态力计算一跨内的弹性分布,如图4所示. 由图4可计算出弹性不均匀系数为16.64%. 按照TB 10621[4]规定,接触网弹性不均匀系数在250 km/h 速度等级需小于15.00%,大于300 km/h 速度等级需小于10.00%. 显然接触线张力为15 kN ,弹性不均匀系数超出了标准要求,将O2-1接触线张力提升至18 kN ,则接触网弹性所有减小,此时的接触网弹性不均匀系数为14.99%,满足标准要求,以该值进行进一步分析. 京沪高铁接触网的弹性不均匀系数为8.73%,满足标准要求.图 4 250 km/h 和350 km/h 速度等级接触悬挂弹性曲线Fig. 4 Elastic curves of contact suspension at250 km/h and 350 km/h在材料确定后,弹性吊索有3个主要参数,分别为截面积、张力和长度. 根据承力索铜绞线标准[18]:2.80 kN 适用的绞线型号为JTMH 25;3.50 kN 适用的第 3 期关金发,等:接触网弹性吊索参数对弓网动态性能影响661绞线型号为JTMH 35. 考虑弹性吊索张力变化范围为2.80、3.15、3.50、3.80 kN ,则绞线截面积为25 mm2和35 mm 2,长度选取14、16、18、22 m ,以下分别建立不同弹性吊索参数下的O2-1、京沪高铁弓网仿真模型,分析弹性吊索参数对弓网动态性能的影响.2 弹性吊索参数对弓网动态性能影响2.1 弹性吊索截面积对弓网动态性能的影响弹性吊索长度为18 m ,当张力为2.80 kN 时,对应截面积选25 mm 2和35 mm 2. 分别计算这两种工况的O2-1、京沪高铁接触网的弓网动态性能.DSA250型受电弓以250 km/h 双弓运行在O2-1接触网,经弓网仿真计算得到接触力曲线如图5所示. 前弓接触力曲线相差不大,后弓两种工况的接触力曲线有一定差别,弹性吊索截面积为25 mm 2的接触力波动较35 mm 2的大.统计250 km/h 等级接触网两种工况分析区段内的接触力和定位点抬升数字特征,如表3所示. 表中:F m 、F min 和F max 分别为接触力的平均值、最小值和最大值;σ为接触力标准差;d up 为定位点最大抬升量. 由表3可知:不同弹性吊索截面积的后弓的接触力标准差均较前弓大;后弓通过弹性吊索截面积为35 mm 2的接触力标准差较25 mm 2小,说明O2-1接触网弹性吊索截面积为35 mm 2的弓网接触质量明显较优;O2-1接触网弹性吊索截面积变化对定位点抬升影响不大. 综合以上分析,得到O2-1接触网弹性吊索截面积宜选用35 mm 2.DSA380型受电弓以350 km/h 双弓运行在京沪高铁接触网,经弓网仿真计算,得到接触力曲线如图6所示. 双弓接触力曲线不重合,但波动幅值接近.图 5 250 km/h 等级接触网接触力Fig. 5 Catenary contact force at 250 km/h表 3 250 km/h 等级接触网接触力统计值Tab. 3 Catenary contact force statistics at 250 km/h level截面积/mm 2F m /N σ/N F min /N F max /N (F max −F min )/N d up /mm 前弓后弓前弓后弓前弓后弓前弓后弓前弓后弓前弓后弓2525120.4120.623.240.468.0 5.7202.0251.6134.0245.981.43535120.4120.624.037.570.433.0195.4218.4125.1185.580.1图 6 350 km/h 等级接触网接触力Fig. 6 Catenary contact force at 350 km/h用35 mm 2.表 4 350 km/h 等级接触网接触力统计值Tab. 4 Catenary contact force statistics at 350 km/h截面积/mm 2F m /N σ/N F min /N F max /N (F max −F min )/N d up /mm 前弓后弓前弓后弓前弓后弓前弓后弓前弓后弓前弓后弓2525186.2187.830.252.699.241.1251.1308.0151.9266.9102.33535187.0185.331.849.896.254.0269.6324.6173.4270.6102.2662西 南 交 通 大 学 学 报第 56 卷2.2 弹性吊索张力对弓网动态性能的影响弹性吊索长度为18 m ,当截面积选35 mm 2时,对应张力可为2.80、3.15、3.50、3.80 kN. 分别计算O2-1、京沪高铁接触网在不同张力下的接触力统计特征值和定位点最大抬升量,如图7和图8所示.图 7 不同弹性吊索张力的接触力最值Fig. 7 Maximum and minimum contact forces withdifferent stitch wire tensions图 8 不同弹性吊索张力的接触力标准差和定位点最大抬升Fig. 8 Standard deviation of contact force and maximum uplift at supporting points with different stitch wire tensions对于250 km/h 等级接触网,随着张力的增加,前弓接触力最小值和最大值的变化并不明显,但后弓则有较明显的变化,后弓接触力最大值逐渐变大,最小值先变小再变大,O2-1接触网弹性吊索张力为2.80 kN 时,后弓接触力最值之差最小;且随着张力的增加,定位点最大抬升缓慢变小,前弓接触力标准差变化不大,而后弓接触力标准差的变化较明显,O2-1接触网弹性吊索张力为2.80 kN 时,后弓接触力标准差最小. 综合以上分析,得到O2-1接触网弹性吊索张力标称值宜选用2.80 kN.对于350 km/h 等级接触网,随着张力的增加,前弓接触力最值之差变大,而后弓接触力最大值先逐渐变小再变大,最小值逐渐变大,京沪高铁接触网弹性吊索张力为3.50 kN 时,后弓接触力最值之差最小. 且随着张力的增加,定位点最大抬升缓慢变小,前弓接触力标准差变化不大,而后弓接触力标准差的变化较明显,京沪高铁接触网弹性吊索张力为3.50 kN 时,后弓接触力标准差最小. 综合以上分析,得到京沪高铁接触网弹性吊索张力标称值宜选用3.50 kN.考虑现场安装弹性吊索张力存在一定的施工公差,O2-1接触网弹性吊索张力在2.80 kN 附近100 N 的特征值与2.80 kN 的特征值接近,京沪高铁接触网弹性吊索张力在3.50 kN 附近100 N 的特征值与3.50 kN 的特征值接近,因此,O2-1接触网和京沪高铁接触网弹性吊索张力宜选用的范围分别为(2.80 ±0.10) kN 和(3.50 ± 0.10) kN.2.3 弹性吊索长度对弓网动态性能的影响当截面积选35 mm 2和张力选2.80 kN 时,弹性吊索长度分别取14、16、18、22 m ,分别计算O2-1、京沪高铁接触网在不同弹性吊索长度下的接触力统计特征值和定位点最大抬升量,如图9和图10所示.图 9 不同弹性吊索长度的接触力最值Fig. 9 Maximum and minimum contact forces withdifferent stitch wire lengths对于250 km/h 等级接触网,随着长度的增加,O2-1接触网的前弓接触力最值之差缓慢变大,后弓接触力最值之差在长度18 m 时最小,值得注意当长度为16 m 时,后弓接触力最小值为0,应避免长度选取16 m ;且随着长度的增加,定位点最大抬升量第 3 期关金发,等:接触网弹性吊索参数对弓网动态性能影响663逐渐增加,前弓接触力标准差变化不大,后弓接触力标准差先变大再变小,当长度为14 m时,后弓接触力标准差最小,定位点最大抬升量最小,当长度为18 m 时,后弓接触力标准差与长度为14 m接近,但定位点最大抬升量相差8 mm. 综合分析以上分析,得到O2-1接触网弹性吊索长度宜选用14 m或18 m.图 10 不同弹性吊索长度的接触力标准差和定位点最大抬升Fig. 10 Standard deviation of contact force and maximum uplift at supporting points with different stitch wire lengths对于350 km/h等级接触网,随着长度的增加,京沪高铁接触网的前弓接触力最值之差逐渐变大,后弓接触力最值之差在长度16 m和18 m较小;且随着长度的增加,定位点最大抬升量逐渐增加,双弓接触力标准差先减小在缓慢变大,当长度为18 m 时,双弓接触力标准差最小,长度为18 m的定位点最大抬升量与长度为14 m相差10 mm. 综合以上分析,得到京沪高铁接触网弹性吊索长度宜选用18 m.250 km/h和350 km/h下弹性吊索长度22 m的定位点最大抬升分别是18 m的111%和117%.3 结 论1) 比较不同弹性吊索参数的弓网动态性能指标,得到适应250 km/h速度等级的O2-1型接触网弹性吊索宜选用线型为JTMH 35 mm2、张力标称值为2.80 kN、张力范围为(2.80 ± 0.10) kN 和长度为14 m 或18 m;适应350 km/h速度等级的京沪高铁接触网弹性吊索宜选用线型为JTMH 35 mm2、张力标称值为3.50 kN、张力范围为(3.50 ± 0.10) kN和长度为18 m.2) 不同工况下双弓通过250 km/h和350 km/h 两种接触网悬挂系统,后弓的接触力波动均比前弓大. 弹性吊索参数变化对前弓的接触力影响较小,对后弓的接触力影响显著.3) 250 km/h和350 km/h下弹性吊索张力的变化对定位点最大抬升影响较小. 250 km/h和350 km/h 下弹性吊索长度22 m的定位点最大抬升是长度18 m 的111%和117%,弹性吊索长度的变化对定位点最大抬升影响显著.致谢:中铁第一勘察设计院院科18-30科研项目的资助.参考文献:吴积钦. 受电弓与接触网系统[M]. 成都: 西南交通大学出版社,2010:121-123.[ 1 ]常丽,李丰良,年晓红. 一种匀弹性接触网[J]. 铁道科学与工程学报,2014(5): 154-158.CHANG Li, LI Fengliang, NIAN Xiaohong. A catenary with equal elasticity[J]. Journal of Railway Science and Engineering, 2014(5): 154-158.[ 2 ]国家铁路局. 高速铁路设计规范:TB 10621—2014[S].北京:中国铁道出版社,2014.[ 3 ]国家铁路局. 高速铁路设计规范条文说明:TB 10621—2014[S]. 北京:中国铁道出版社,2014.[ 4 ]关金发,吴积钦,李岚. 弓网动态仿真技术的现状及展望[J]. 铁道学报,2015(10): 35-41.GUAN Jinfa, WU Jiqin, LI Lan. The status andprospects of pantograph and catenary dynamic simulation technology[J]. Journal of the China Railway Society, 2015(10): 35-41.[ 5 ]BRUNI S, AMBROSIO J, CARNICERO A. Theresults of the pantograph and catenary interaction benchmark[J]. Vehicle System Dynamics, 2015, 53(3):412-435.[ 6 ]汪吉健,田志军,李会杰,等. 承力索张力对弓网受流质量影响研究[J]. 铁道学报,2005,27(1): 114-118.WANG Jijian, TIAN Zhijun, LI Huijie, et al. Study of The influence of current-receiving quality between pantograph and OCS from tensile force acting on catenary wire[J]. Journal of the China Railway Society,2005, 27(1): 114-118.[ 7 ]张卫华,梅桂明,陈良麒. 接触线弛度及表面不平顺对接触受流的影响分析[J]. 铁道学报,2000,22(6):50-54.ZHANG Weihua, MEI Guiming, CHEN Liangqi.Analysis of the influence of catenary’ sag and irregularity upon the quality of current-feeding[J]. Journal of China Railway Society, 2000, 22(6): 50-54.[ 8 ]HARELL P, DRUGGE L, REIJM M. Study of critical sections in catenary systems during multiple pantograph [ 9 ]664西 南 交 通 大 学 学 报第 56 卷operation[J]. Proceedings of the Institution of Mechanical Engineers ,Part F :Journal of Rail & Rapid Transit , 2005, 219(4): 203-211.POMBO J , AMBROSIO J.Influence of theaerodynamic forces on the pantograph and catenary system for high-speed trains[J]. Vehicle System Dynamics , 2009, 47(11): 1327-1347.[10]赵飞,刘志刚,韩志伟. 随机风场对弓网系统动态性能影响研究[J]. 铁道学报,2012,34(10): 36-42.ZHAO Fei , LIU Zhigang , HAN Zhiwei. Simulation study on influence of stochastic wind field to dynamic behavior of pantograph-catenary system[J]. Journal of China Railway Society , 2012, 34(10): 36-42.[11]周宁,张卫华. 双弓作用下弓网动力学性能[J]. 西南交通大学学报,2009,44(4): 552-557.ZHOU Ning , ZHANG Weihua. Dynamic performance ofpantograph-catenarysystem withdouble pantographs[J].JournalofSouthwestJiaotongUniversity , 2009, 44(4): 552-557.[12]吴燕,吴俊勇,郑积浩,等. 高速受电弓-接触网动态受流性能及双弓距离的研究[J]. 铁道学报,2010,32(4): 38-43.WU Yan , WU Junyong , ZHENG Jihao , et al. Study on current-collection of high-speed pantograph-catenary system and distance between two pantographs[J].Journal of China Railway Society , 2010, 32(4): 38-43.[13]李文豪,崔校玉,陈维荣. 弹性链型悬挂高速接触网[14]参数的选取研究[J]. 铁道工程学报,2009,26(8): 82-87.LI Wenhao , CUI Xiaoyu , CHEN Weirong. Research on the selection of parameters for the overhead contact line system with stitch wire on high speed railway[J].Journal of Railway Engineering , 2009, 26(8): 82-87.关金发,吴积钦. 受电弓与接触网动态仿真模型建立及其确认[J]. 铁道科学与工程学报,2017,14(11): 2444-2451.GUAN Jinfa , WU Jiqin. Building and confirmation for dynamic simulation model of pantograph and catenary[J].JournalofRailwayScienceandEngineering , 2017, 14(11): 2444-2451.[15]陈维荣,李文豪,张倩. 几种高速受电弓/接触网系统性能的比较[J]. 西南交通大学学报,2009,44(3): 354-359.CHEN Weirong ,LI Weihao ,ZHANG Qian.Comparison of dynamic performance of several pantograph/catenary systems for high-speed railway[J].Journal of Southwest Jiaotong University , 2009,44(3): 354-359.[16]European Community. Railway application Currentcollection systems technical criteria for the interaction between pantograph and overhead line :EN 50367[S].Brussels :CENELEC , 2012.[17]国家铁路局. 电气化铁道用铜及铜合金绞线:TB/T3111—2017[S]. 北京:中国铁道出版社,2017.[18](中文编辑:李永辉 英文编辑:周 尧)(上接第639页)陈道云,孙守光,李强. 高速列车载荷谱推断及扩展方法研究[J]. 机械工程学报,2018,54(10): 151-155.CHEN Daoyun , SUN Shouguang , LI Qiang. Study on deduction and extend of high-speed train load spectrum[J]. Journal of Mechanical Engineering ,2018, 54(10): 151-155.[12]刘义伦,ZENNER H. 关于标准载荷累积频次谱的外推[J]. 中南矿冶学院学报,1991,22(5): 556-562.LIU Yilun , ZENNER H. Extrapolation about standard collection curves[J]. Journal of Central South University , 1991, 22(5): 556-562.[13]黄鹏,蔡玢,全涌,等. 基于实测的低矮房屋屋面风压极值计算方法[J]. 西南交通大学学报,2014,49(2):247-253.[14]HUANG Peng , CAI Bin , QUAN Yong , et al. Peak pressure estimation method of wind loads on low-rise building based on field measurement[J]. Journal of Southwest Jiaotong University , 2014, 49(2): 247-253.BALKEMA A A , DE HAAN L. Residual life time atgreat age[J]. The Annals of Probability , 1974, 2(5):792-804.[15]EMBRECHTS P , KLÜPPELBERG C , MIKOSCH T.Modelling extremal events for insurance and finance[M]. Berlin : Springer , 1997.[16]邹骅. 城际动车组转向架构架载荷谱研究[D]. 北京:北京交通大学,2016.[17]PICKANDS J. Statistical inference using extreme orderstatistics[J]. The Annals of Statistics , 1975, 3(1): 119-131.[18](中文编辑:李永辉 英文编辑:周 尧)第 3 期关金发,等:接触网弹性吊索参数对弓网动态性能影响665。
康复悬吊知识点总结
康复悬吊知识点总结康复悬吊的原理是利用重力辅助患者恢复肌肉力量和平衡能力。
在悬挂的状态下,患者可以进行各种运动训练,如走路、踢腿、做深蹲等。
由于身体重量被减轻了,患者可以更轻松地进行运动训练,从而加快康复速度。
另外,在悬挂的状态下,患者往往可以更好地感受自己的身体姿势和动作,有利于改善姿势控制和平衡能力。
康复悬吊的装置通常由悬吊系统和支撑系统两部分组成。
悬吊系统包括悬吊绳索、吊具和升降装置,用于将患者悬挂在空中并调整悬挂高度。
支撑系统包括身体支撑带、腰围、腿固定带等,用于固定患者的身体,保证其安全稳定地进行训练。
此外,为了满足不同患者的康复需求,还可以根据具体情况选择不同的悬吊装置,如步态训练器、上肢训练器、踏步训练器等。
康复悬吊的训练方法多种多样,可以根据患者的具体病情和康复目标进行个性化设计。
一般来说,康复悬吊训练可以分为静态悬吊和动态悬吊两种。
静态悬吊是指患者在悬挂状态下进行固定姿势训练,如站立、踢腿、腰部训练等。
这种训练方法可以帮助患者改善姿势控制和平衡能力,增强肌肉力量。
动态悬吊是指患者在悬挂状态下进行动作训练,如走路、跑步、踏步等。
这种训练方法可以帮助患者恢复步态功能,提高运动协调性。
康复悬吊训练的注意事项包括患者的身体状况、训练强度和训练频率。
患者的身体状况是制定训练计划的重要依据,针对不同的病情和康复目标,需要采用不同的训练方法和强度。
训练强度和训练频率应该由专业的康复医生或康复治疗师根据患者的具体情况来确定,以免造成过度疲劳或不适。
另外,悬吊训练过程中需要严格控制患者的安全,确保其在悬挂状态下不会发生意外。
康复悬吊训练的效果主要取决于患者的积极配合和专业团队的指导。
患者需要在康复医生或康复治疗师的指导下进行训练,按照训练计划完成每次训练任务。
专业的康复团队需要具备丰富的康复经验和专业的康复知识,能够根据患者的具体情况和康复目标设计个性化的训练方案,并严格监控训练效果,随时调整训练计划。
城市轨道交通专业英语翻译
Urban Metro CHARACTERISTICS 城市地铁特点Comfort舒适性Shortcut捷径Punctuality守时Little pollution小污染Safety安全性1、车体2、转向架3、牵引缓冲装置4、制动装置5、采集装置6、内部设备7、电气设备1.Car body 车体◆It is to accommodate passengers and the driver.这是为了容纳乘客和司机。
◆Meanwhile, it is the basic component to connect to other devices or car bodies.同时,它是连接到其他设备或汽车车身的基本部件。
◆For the purpose of meeting the strength requirement while keeping the self-weight at itslowest.为了满足强度要求,同时保持自重最低。
◆Integrated steel structure or light metal structure is adopted.采用整体式钢结构或轻型金属结构。
◆It usually comprises of the floor, the roof, sides and end walls.它通常包括地板、屋顶、侧壁和端壁。
2.Bogies 转向架◆Motor and trailer bogies are located between the car body and the track, to drag andguide the vehicles moving along the track.汽车和拖车转向架位于车体与轨道之间,拖曳和引导车辆沿轨道运动。
◆They cab bear and transfer a variety of load from lines and the car body, easing itsdynamic action.他们从线路和车体上承担和传递各种载荷,减轻其动力作用。
悬索桥设计论文
本科毕业设计成果小跨度吊桥设计作者姓名朱杰指导教师秦值海所在院系浙江工业大学专业班级土木09提交日期2011年10月7日小跨度吊桥设计The Design of Shot-span Suspension BridgeAbstract学生姓名:朱杰Student: ZhuJie指导教师:秦值海Advisor: QinZhiHai浙江工业大学成人教育学院毕业设计成果A ThesisSubmitted to Zhejiang University of Technologyin Partial Fulfillment of the Requirementsfor the Undergraduate Thesis in Automation2012年6月摘要本设计为公路(13m+68m+13m)三跨柔性悬索桥,主跨68m,边跨对称13m。
桥面系为钢结构,桥塔为钢筋混凝土结构。
悬索桥很早以前就有了,到了近代发展速度十分迅猛,在现代桥梁工程实践中开始广泛应用,其特点是受力性能好、跨越能力大、轻型美观、抗震性能好。
是跨越大江大河、海峡港湾等交通障碍的首选桥型。
本设计以悬索桥设计基本理论和静动力分析为理论基础,以成功修建的悬索桥为例,根据桥梁的位置、布置形式,拟定桥梁的跨度、矢高、吊杆间距、锚索倾角、桥塔高度和截面、塔基形式、锚碇构造等,说明选择相关参数的过程、依据、和考虑的主要因素,然后进行桥面系、主索边索、吊杆、索夹、抗风索、桥塔、锚碇等具体尺寸设计、配筋和验算。
桥面系采用工字钢横纵梁布置,主索用7×19钢丝绳,桥塔用C20钢筋混凝土,本桥相对悬索桥跨度较小,设计考虑恒载、风荷载和温度荷载,活载为汽-10和人行荷载,不考虑地震荷载。
由于悬索桥是超静定结构,计算较为烦琐,故在该设计中,结构单元划分和内力计算采用专业设计软件ansys进行,计算方法为有限元法,使设计工作量大大的简化,内力求出后,根据桥梁规范进行结构内力组合。
三塔以上悬索桥关键力学行为及结构成立特征
第51卷第3期2021年5月 东南大学学报(自然科学版)JOURNALOFSOUTHEASTUNIVERSITY(NaturalScienceEdition)Vol.51No.3May2021DOI:10.3969/j.issn.1001-0505.2021.03.005三塔以上悬索桥关键力学行为及结构成立特征王 路1,3 侯 康2 沈锐利3 甄晓霞1(1华南理工大学土木与交通学院,广州510641)(2中交公路规划设计院有限公司,北京100088)(3西南交通大学土木工程学院,成都610031)摘要:为探究三塔以上悬索桥在不同跨径及桥塔数目时的力学行为和成立特征,建立了主跨径为500~1500m、桥塔数目为3~8的24个悬索桥计算模型,明确了竖向刚度及主缆抗滑的最不利简化布载模式,分析了汽车荷载和温度荷载作用、结构振型基频以及颤振临界风速,探讨了中塔纵向刚度对结构成立特征的影响.结果表明:单主跨及单侧简化满载可分别用于最不利竖向挠度及抗滑安全分析;加劲梁竖向挠度仅在桥塔数目由3增至4时存在明显跃升;抗滑安全性对桥塔数目变化不敏感,但随主跨径的增加而显著提高;加劲梁温致纵向变形较大,可通过优化塔梁约束体系加以解决;桥塔数目奇偶性影响结构正/反对称横弯的次序,主跨径增加会导致各振型基频及颤振临界风速显著减小;三塔以上悬索桥中塔效应更为突出,缆鞍间摩擦系数取值为0.3时结构成立空间大幅增加.关键词:多塔悬索桥;简化布载模式;静动力行为;结构竖向刚度;抗滑安全性;中塔纵向刚度中图分类号:U448.25 文献标志码:A 文章编号:1001-0505(2021)03 0391 07KeymechanicalbehaviorsandstructuralestablishmentcharacteristicsofsuspensionbridgewithmorethanthreepylonsWangLu1,3 HouKang2 ShenRuili3 ZhenXiaoxia1(1SchoolofCivilEngineeringandTransportation,SouthChinaUniversityofTechnology,Guangzhou510641,China)(2CCCCHighwayConsultantsCo.,Ltd.,Beijing100088,China)(3SchoolofCivilEngineering,SouthwestJiaotongUniversity,Chengdu610031,China)Abstract:Toinvestigatethemechanicalbehaviorsandestablishmentcharacteristicsofsuspensionbridgeswithmorethanthreepylons(SBMTP)fordifferentspansanddifferentnumbersofpylons,24calculationmodelsforthesuspensionbridgewiththemainspanof500to1500mandthepylonnum berof3to8werebuilt.Themostunfavorablesimplifiedloadingmodesoftheverticalstiffnessandtheanti slipofthemaincablewereclarified.Theactionsofthevehicleandtemperatureloads,thestructuralmodalshapesandfundamentalfrequencies,andthefluttercriticalwindspeedswereana lyzed.Theeffectsofthelongitudinalstiffnessofthemid pylononthestructuralestablishmentcharac teristicswerediscussed.Theresultsshowthatthemostunfavorableverticaldeflectionandanti slipsafetycanbeanalyzedaccordingtothesimplifiedfull loadingonsinglemainspanandsingleside,re spectively.Theverticaldeflectionofthestiffeninggirdergrowssignificantlyonlywhenthepylonnumberincreasesfrom3to4.Theanti slipsafetyofthemaincableisnotsensitivetothenumberofthepylons,butincreasessignificantlywiththeincreaseofthemainspan.Thetemperature inducedlongitudi naldeformationofthestiffeninggirderislarge,whichcanbesolvedbyoptimizingthepylon girderre straintsystem.Theparityofthepylonnumberaffectstheorderofsymmetricandanti symmetriclateralbending.Increasingthemainspancanreducethefundamentalfrequencyofeachmodalshapeandthefluttercriticalwindspeed.Themid pyloneffectoftheSBMTPismoreprominent.Whenthecable sad dlefrictioncoefficientistakenas0.3,thestructuralestablishmentscopecanbesignificantlyincreased.Keywords:multi pylonsuspensionbridge;simplifiedloadingmode;staticanddynamicbehavior;verticalstiffnessofstructure;anti slipsafety;longitudinalstiffnessofmid pylon收稿日期:2020 12 15. 作者简介:王路(1990—),男,博士,助理研究员;沈锐利(联系人),男,博士,教授,博士生导师,rlshen@163.com.基金项目:国家自然科学基金资助项目(51178396,51678247)、中国博士后科学基金资助项目(2020M672634)、广东省基础与应用基础研究基金资助项目(2020A1515110240).引用本文:王路,侯康,沈锐利,等.三塔以上悬索桥关键力学行为及结构成立特征[J].东南大学学报(自然科学版),2021,51(3):391397.DOI:10.3969/j.issn.1001-0505.2021.03.005. 多塔悬索桥因突出的跨越能力和良好的经济性被视为跨越宽阔水域的理想桥型[12].但由于中塔缺少主缆的有力约束,桥面存在极端偏载的交通可能,导致全桥结构刚度和主缆抗滑安全性难以兼顾,成为阻碍多塔悬索桥应用和发展的关键问题[23].为此,国内外学者从适宜结构体系[47]和缆鞍间抗滑性能[811]两个方面开展了相关研究,促进了对于多塔悬索桥的认知,并成功推动了以泰州长江大桥和温州瓯江北口大桥为代表的三塔悬索桥的工程建设.然而,三塔悬索桥由于仅增加了1个主跨,其跨越能力仍难以满足海湾、海峡等长大联络工程的跨度需求.继续增加桥塔、发展成为三塔以上悬索桥,是进一步提升桥梁连跨能力和适用范围的合理思路.但目前尚无大跨径三塔以上悬索桥的建设案例,少有的前瞻性研究也均以已建三塔悬索桥为工程原型,局限于特定的跨径或中塔数目及形式[12],无法系统表征其他桥位处需以更多的桥塔及跨径组合实现更长跨越时的结构力学行为及成立特征.基于此,本文构建了不同主跨径、不同桥塔数目的悬索桥计算模型,通过计算得到关键指标的最不利简化布载模式,探明了三塔以上悬索桥的关键静动力特性,讨论了适应结构刚度及主缆抗滑需求的中塔设计区间.研究结论可为三塔以上多塔悬索桥的科学化设计建造提供指导.1 研究对象1.1 设计参数设计参数主要包括矢跨比、边中跨比和主跨径.较大的矢跨比能为悬索桥提供更好的力学性能[5].目前,国内已建的大跨径三塔悬索桥皆取规范建议的上限值1/9[13].边中跨比一般由实际桥位的地形地质条件决定,规范建议取值为0.25~0.45[13],在此区间内调整对结构总体并无显著影响[5].为此,本文中各桥的矢跨比取1/9,边中跨比取0.3.考虑到目前已建三塔悬索桥的主跨径为800~1100m,在此基础上适当延拓,拟定本文计算模型的主跨径为500~1500m.桥塔数目设为4~8.参考近年来建造的钢箱梁悬索桥的桥塔设计参数[3],拟定边塔纵向刚度为8MN/m,中塔纵向刚度为6.5MN/m.加劲梁采用典型钢箱梁断面,梁高3m,梁宽38.5m,梁体恒载为233.5kN/m,在最中间桥塔处设置纵向约束,若桥塔数目为偶数则偏右侧桥塔设置.主缆抗拉强度为1770MPa,其截面积按等强度原则拟定.基础结构见图1.图1 研究对象结构布置情况1.2 计算模型利用BNLAS软件建立了由4种主跨径(500、800、1100、1500m)和6种桥塔数目(3~8)组合而成的24个多塔悬索桥有限元模型,并将三塔情况作为参考组.典型模型如图2所示,模型中采用索单元模拟主缆,采用空间梁单元模拟桥塔和加劲梁.模型计算显示,各桥恒载状态均达到设计线形,且吊索力较均匀,证明了参数拟定及模型构建的合理性.图2 有限元计算模型2 汽车荷载作用分析汽车荷载作用下结构竖向刚度和主缆抗滑安全性是多塔悬索桥的关键指标[3,6].本研究中汽车荷载采用八车道公路Ⅰ级标准,结构竖向刚度以挠跨比(即加劲梁最大挠度与主跨径之比)不超过1/250~1/300进行界定[13].主缆抗滑安全性根据规范[13]进行评估,抗滑安全系数计算公式为K=μαsln(Fct/Fcl)≥2(1)式中,μ为主缆与索鞍间摩擦系数,规范[13]取值为0.15;αs为索鞍上的主缆包角;Fct、Fcl分别为紧边侧及松边侧的主缆轴力.三塔以上悬索桥连续跨度大,若仍按影响线布置汽车荷载,则计算耗时过长,难以开展广泛的参数研究.本文将通过规模化的模型计算,明确结构竖向刚度及主缆抗滑安全对应的最不利简化布载模式.2.1 结构竖向刚度2.1.1 简化布载模式全模型计算结果表明,各桥的最大挠度发生于中央跨的相邻跨;若相邻跨为边跨时,则最大挠度发生于中央跨.图3给出了各桥目标主跨的挠度影293东南大学学报(自然科学版) 第51卷http://journal.seu.edu.cnhttp://journal.seu.edu.cn响线,对应的简化布载模式是在目标主跨内满载.进一步分别计算简化加载与影响线加载时各桥的最大挠度,结果显示两者最大偏差约1%,表明所归纳的简化布载模式是有效的.图3 加劲梁竖向挠度最不利简化布载模式2.1.2 计算结果分析汽车荷载作用下加劲梁竖向挠度见图4.因结构对称,各桥仅示出半侧情况.图中,x为加劲梁距中塔1的距离;L为主跨径.由图4可知,相对于一端为中塔、另一端为边塔的边主跨,两端均为中塔的中主跨将产生高约30%的竖向挠度,本质上是对中塔缺少边跨主缆强劲约束这一结构特征的力学响应.由于三塔悬索桥最大挠度明显高于同等主跨径的两塔悬索桥[3],故可推知三塔以上悬索桥将进一步超出传统两塔悬索桥保有的挠度界限.另一方面,主跨径相同、桥塔数目不同的悬索桥边主跨竖向挠度差异不大,同一桥中不同中主跨的挠度曲线接近,说明三塔以上悬索桥既继承了三塔悬索桥边主跨的变形特征,又存在某种与串联式悬索桥类似的主跨独立的力学现象.(a)三塔(b)四塔(c)五塔(d)六塔(e)七塔(f)八塔图4 加劲梁竖向挠度 各桥挠跨比见图5.由图可知,桥塔数目由3变为4时,挠跨比发生显著跃升,增幅达35%,明显超出了规范[13]限值1/250;而后桥塔数目继续增加,挠跨比增幅不大.因此,三塔以上悬索桥面临图5 各桥挠跨比更突出的竖向刚度问题,但主要存在于四塔悬索桥.此外,多塔悬索桥的主跨径越大,虽然竖向挠度更大,但挠跨比更小,更易满足结构刚度要求.2.2 主缆抗滑安全性2.2.1 简化布载模式由式(1)可知,主缆抗滑在结构层面上取决于索鞍两侧的缆力比.考虑到缆力比与中塔纵向位移间的正相关性,将中塔纵向位移作为中间量来研究简化布载.模型计算表明,最大中塔纵向位移均发生在有纵向约束的中央桥塔处.图6给出了中央桥塔纵向位移的影响线,对应的最不利简化布载模式是在中央桥塔一侧的各跨满载.分别按照简化加载393第3期王路,等:三塔以上悬索桥关键力学行为及结构成立特征http://journal.seu.edu.cn与影响线加载计算各桥中塔最大位移,结果基本一致,最大偏差约为5%,表明所得简化布载模式是有效的.图6 中塔纵向位移最不利简化布载模式2.2.2 计算结果分析汽车荷载作用下,各桥主缆最小抗滑安全系数见图7.由图可知,抗滑安全系数随桥塔数目的增多逐渐减小,但减幅有限,且未出现类似图5中的突变现象,说明桥塔数目并非多塔悬索桥主缆抗滑安全的控制因素.相比之下,跨径影响明显,且主跨径越大,对应的抗滑安全系数越高,说明结构恒载比重的提升削弱了活载下主缆滑移风险的内在机制.由此可知,多塔悬索桥采用较大的主跨径,有助于协同优化结构竖向刚度与主缆抗滑安全系数.就规范要求而言,当主跨径小于1100m时,各结构主缆抗滑安全系数均低于2.因此,对于三塔以上悬索桥,基于拟定的中塔纵向刚度,均存在无法满足现行规范中关于结构竖向刚度或主缆抗滑安全性要求的桥跨组合.图7 主缆最小抗滑安全系数3 温度效应分析三塔以上悬索桥长度大,温度作用重点体现于梁端纵向变形.计算采用整体升/降温:钢构件升/降温25℃,混凝土构件升/降温20℃.图8给出了各桥小里程梁端的纵向位移.图8 温度荷载下加劲梁端部纵向位移由图8可知,温度荷载作用下加劲梁纵向变形明显,且随主跨径及桥塔数目的增加而增加,因此对于大跨度多塔悬索桥,温致纵向变形会超出常规梁端设置伸缩装置的应对范围,这也是多塔缆索承重桥梁的共性问题.工程实践中,建造嘉绍六塔斜拉桥时,通过在主梁跨中设置箱梁嵌套的刚性铰式构造较好地解决了加劲梁的温致变形问题.而对于多塔悬索桥,主缆需连贯各跨,但加劲梁可在塔处断开,故还可从塔梁约束体系方面应对温致变形问题,如鹦鹉洲三塔悬索桥采用的两铰体系,可缩短加劲梁连跨长度、减小温致变形.因此,对于多塔悬索桥,特别是三塔以上悬索桥,可以结合具体情况在部分甚至所有中塔处通过优化塔梁约束体系来应对加劲梁温致变形,展现出更灵活的设计自由度.4 动力特性分析以振型基频及颤振临界风速为研究对象,分析结构动力特性,结果见图9.图中,颤振临界风速是基于vanderPut公式[14]计算得到的.由图9可见,桥塔数目对多塔悬索桥竖弯、横弯、扭转基频以及颤振临界风速的大小影响不明显.但桥塔数目的奇偶性对结构正/反对称横弯的出现次序影响规律明显:桥塔数目为奇数时先出现正对称横弯,反之则先出现反对称横弯.竖弯的正/反对称振型频率基本一致,且与桥塔数目之间并无次序规律.多塔悬索桥动力特性对于主跨径的变化更为敏感,随着主跨径的增加,各结构基频均大幅减小,颤振临界风速也相应降低.当主跨径由500m增至1500m时,颤振临界风速减小了50%以上.因此,对于大主跨的多塔悬索桥,除了固有的中塔效应问题,结构抗风安全性问题亦需高度重视.5 中塔刚度影响分析5.1 结构竖向刚度调整中塔纵向刚度,各桥挠跨比见图10.图中493东南大学学报(自然科学版) 第51卷http://journal.seu.edu.cn(a)主跨500m(b)主跨800m(c)主跨1100m(d)主跨1500m图9 振型基频及颤振临界风速平面表示1/250的规范界限.由图可知,随着中塔纵向刚度的增加,各桥挠跨比明显降低,结构竖向刚度显著提升.当中塔纵向刚度增至10MN/m时,各三塔悬索桥均可满足规范要求;当中塔纵向刚度增至15MN/m时,主跨径为1100、1500m的三塔以上悬索桥能够满足规范要求;当中塔纵向刚度增至20MN/m时,主跨径为500、800m的各桥均能满足规范要求.由此可见,多塔悬索桥竖向刚度指标对中塔纵向刚度反应灵敏,在适度范围内调整中塔纵向刚度便可使结构竖向刚度满足规范要求.实际结构设计时,可通过合理选择中塔形式得出合适的纵向刚度,如采用人字形中塔时可调整桥塔两肢间距及分岔高度.(a)主跨500m(b)主跨800m(c)主跨1100m(d)主跨1500m图10 不同中塔纵向刚度时的各桥挠跨比5.2 主缆抗滑安全性调整中塔纵向刚度,各桥主缆抗滑安全系数见图11.图中平面表示缆鞍间摩擦系数μ取不同值时对应的2倍抗滑安全系数的界限.由图可见,增加中塔刚度会对主缆抗滑安全产生显著的削弱作用.按照规范建议值μ=0.15,当中塔刚度增加到10MN/m时,各桥均已无法满足主缆抗滑安全要(a)主跨500m(b)主跨800m(c)主跨1100m(d)主跨1500m图11 不同中塔纵向刚度时的主缆抗滑安全系数593第3期王路,等:三塔以上悬索桥关键力学行为及结构成立特征求;对照图10可知,此时三塔以上悬索桥不存在能够同时满足结构竖向刚度和主缆抗滑需求的中塔纵向刚度,即结构无法成立.5.3 应对策略分析由于结构竖向刚度事关全桥安全稳定性,在工程中进一步放宽挠跨比要求的实际可操作性有限,因此突破多塔悬索桥发展困境的策略重心在于主缆抗滑方面,其关键途径是对主缆与索鞍间摩擦系数进行合理设计取值.为此,前期开展了相关的试验及理论研究:大规模主缆抗滑试验表明,摩擦系数设计值取0.2足够安全[10];通过有效计算及利用主缆与索鞍间的侧面摩阻[15],或采取在鞍槽内增设摩擦板的构造措施[11],可使摩擦系数设计值进一步提高至0.3及以上.由图11可知,当μ=0.2时,主缆抗滑压力大幅缓解,主跨径为1100、1500m时中塔纵向刚度可分别增加到15、20MN/m,说明此跨径范围内的三塔以上悬索桥已存在适合的中塔设计刚度;当μ=0.3时,即使中塔纵向刚度取至20MN/m,文中所有结构也都能满足主缆抗滑要求,中塔纵向刚度可完全由结构竖向刚度的具体限值而定.综上可知,基于现有理论技术储备,三塔以上悬索桥能够获得同时满足结构刚度和主缆抗滑的中塔刚度区间,具备理论层面上的适用前景.6 结论1)对于三塔以上悬索桥,竖向刚度对应的最不利简化布载模式是在中央跨的邻跨满载,若邻跨为边主跨则满载于中央跨;主缆抗滑对应的最不利简化布载模式是在中央桥塔的一侧满载.2)汽车荷载下,三塔以上悬索桥的加劲梁竖向挠度明显高于同等主跨径的三塔悬索桥.桥塔数目对边主跨的挠度影响较小,同桥各中主跨的挠度接近.挠跨比仅在由三塔增到四塔时出现跃升.主缆抗滑安全系数对桥塔数目不敏感,但随主跨径的增加而显著提高.温度荷载下,三塔以上悬索桥的加劲梁纵向变形明显,可从塔梁约束体系合理化设计方面寻求解决方法.3)桥塔数目对振型基频及颤振临界风速的影响较小,但桥塔数目奇偶性会影响结构正/反对称横弯的出现次序.三塔以上悬索桥的各振型基频及颤振临界风速均随主跨径的增加而大幅减小,故需就该桥型的抗风抗震等动力问题进行进一步的深入研究.4)三塔以上悬索桥存在突出的中塔效应问题,难以满足现行规范对于结构刚度及主缆抗滑的要求.基于已有研究,若将缆鞍间摩擦系数取至0.3,则容易获得满足要求的中塔设计刚度,由此大幅拓展三塔以上悬索桥的结构成立区间.参考文献(References)[1]ThaiHT,ChoiDH.Advancedanalysisofmulti 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实用英语词汇系列:电子翻译词汇_Part3
dynamic range,动态范围dynamix range of microphone,传声器动态范围dynamic resolution,动态分辨力dynamic response,动态响应dynamic SIMS,动态二次离子质谱法dynamic standard strain device,动态标准应变装置dynamic stiffness,动刚度dynamic stiffnesss of the moving element suspension,运动部件悬挂动刚度dynamic stiffenss ratio,动刚度比dynamic storage allocation,动态存储分配dynamic strain,动应变dynamic strain indicator,动态应变仪dynamic thermomechanical analysis,动态热机械分析dynamic thermomechanical analysis apparatus,动态热机械分析仪dynamic thermomechanometry,动态热机械法dynamic(two-plane)balancing,动(双面)平衡dynamic(two-plane)balancing machine,动(双面)平衡机 dynamic unbalance,动态不平衡dynamic vane bias,风向标的动力偏幅dynamic viscosity,动力粘度dynamic water tank,动水槽dynamic wieghing method,动态称重法dynamometric system,测力系统电子类词汇E-JEearly failue,早期失效earth leakage detector,接地漏电检示器earth resistance meter,接地电阻表earth resource technology satellite(ERTS),地球资源技术卫星earthed input,接地输出earthed voltage transformer,接地型电压互感器ease of ignition,易起燃性eccentric load,偏心载荷eccentric orifice plate,偏心孔板eccentricity of rotor,转子偏心距echelon grating,阶梯光栅echo,反射波;回波echo height,反射波高度echo sounder,回声测深仪ecobuoy,生态浮标economic analysis,经济分析economic control,经济控制economic control theory,经济控制理论economic cybernetics,经济控制论economic data,经济数据economic decision,经济决策economic effectiveness,经济效益economic environment,经济环境economic evaluation,经济评价economic forecast,经济预测economic index,经济指数economic indicator,经济指标economic model,经济模型economic system model.经济系统模型eddy-current,涡流eddy-current displacement vibration amplitude measuring instrument, 电涡流式位移振幅测量仪eddy-current displacement vilbration amplitude transducer,电涡注式位移振幅传感器 eddy curent inspection instrument,涡流探伤仪eddy current testing method,涡流探伤法eddy-current thickness meter,电涡流厚流计eddy-current type transducer,涡流式传感器eddy diffusion,涡流扩散eddy velocity,涡动速度edge effect,边缘效应EDM instrument,电磁波测距仪effective aperture,有效孔径effective area,有效面积effective data transfer rate,有效数据传送率effective diaphragm area,膜片有效面积effective emissivity,有效发射率effective excitaion force,有效激振力effective magnetic field,有效磁场effective mass of the moving element,运动部件有效质量effective path length,有效光程长度effective radiation exitance,有效辐(射)出(射)度effective range,有效范围;有效量限;测量范围effective sound pressure,有效声压effectiveness,有效性effectiveness theory,效益理论efflux viscometer,流出式粘度计egoless programming,无私程序设计egoless programming,无私程序设计EI-CI source,电子轰击—化学电离源eigen frequency,特征频率Ekman current meter,厄克曼海流计elastic after-effect,弹性后效elastic background,弹性元件elastic limit,弹性极限elastic scatter,弹性散射elastic system,弹性系统elasticity,弹性elastomer diaphragm,橡胶膜片electret microphone,驻极体传声器electric actuator,电动执行机构electric contact liquid-in-glass thermometer,电接点玻璃温度计electric contact set,电接点装置electric control,电动控制electric current transducer[sensor],电流传感器electric field controller,电场控制仪electric field strength transducer[sensor],电场强度传感器electric hydraulic converter,电—液转换器electric logger,电测井仪器electric measurement technique of strain gauge,应变计电测技术electric operationg station,电动操作器electric pneumatic converter,位置发送器electric quantity transducer[sensor],电学量传感器electric resistance and dielectric constant measuring unit, 电阻—静电容量测量仪 electric system,电气系统electrical capacitance level measuring device,电容物位测量装置electrical center,电中心dlectrical conductance level measuring device,电导液闰测量装置electrical conductivity detector,电导检测器electrical hygrometer,电气湿度计;电测湿度表electrical(measurement)method,电测法electrical measurement method of optical pyrometer,光学高温计电测法electrical measuring instrument,电(工)测量仪器仪表;电法勘探仪器electrical power consumption ,(电)功耗electrical resonance frequency of the miving element,运动部件电谐振频率electrical signal,电信号electrical thermometer,电测温度表electrical wind vane and anemometer,电传风向风速仪electrical zero,电零位;电零点electrical zero adjuster,电零位调节器;电零点调整器electrically heated drying cabinet,电热干燥箱electro-cardiography transducer[sensor],心电图(ECG)传感器electo-hydraulic servocontrolled fatigue testing machine,电液伺服疲劳试验机 electro-optical distance meter,光电测距仪electroacoustic transducer,电声换能器electroacoustical reciprocity theorem,电声互易定理electrochemical analysis,电化学分析(法)electrochemical analyzer,电化学式分析器electrochemical transducer[sensor],电化学式传感器electrode,电极electrode potential,电极电位electrode signal,电极信号electrode type salinometer,电极式盐度计electrode with a mobile carrier,流动载体电极electrodeless-discharge lamp,无极放电灯electrodialysis method for desalination,电渗析淡化法electrodynamic instrument,电动系仪表electrodynamic meter,电动系电度表electrodynamic vibrator,电动振动器electroence-phalographic transducer[sensor],脑电图(EEG)传感器electrogravimetric analysis,电重量分析(法)electrohydraulic control,电液执行机构electrohydraulic control,电液伺服阀electrolysis humidity transducer[sensor],电解式湿度传感器electrolytic cell,电解池electrolytic hygrometer,电解湿度计electromagnet,电磁铁electromagnet damping galvanometer,电磁阻尼振动子electromagnet fluid damping galvanometer,电磁液体阻尼振动子electromagnetic brake,电磁制动器electromagnetic braking,电磁制动electromagnetic counter,电磁计数器electromagnetic current meter,电磁海流计electromagnetic damper,电磁阻尼器electromagnetic deflector alignment system,电磁偏转对中系统electromagnetic distance meter,电磁波测距仪electromagnetic element,电磁元件electromagnetic flowmeter,电磁流量计electromagnetic gun,电磁枪electromagnetic induction,电磁感应electromagnetic interference,电磁感应法仪器electromagnetic imterference,电磁干扰electromagnetic lens,电磁透镜electromagnetic method instrument,电磁法仪器electromagnetic methods,电磁法electromagnetic radiation,电磁辐射electromagnetic screen,电磁屏蔽electromagnetic transducer[sensor],电磁式传感器electromagnetic unit,电磁单元electromagnetic vibrator,电磁振动器electromagnetic wave propagation logging instrument,电磁波传播测井仪 electrometer,静电表electromotive force(EMF),电(动)势electromyogrphic transducer[sensor],肌电图(EMG)传感器electron beam exposure apparatus,电子束曝光机electron beam processing machine,电子束加工机electron capture detector(ECD),电子捕获检测器electron channelling pattern,电子通道花样electron diffraction image,电子衍射象electron diffractometer,电子衍射谱仪electron energy lose spectroscopy(EELS),电子能量损失谱法electron gun,电子枪electron gun alignment adjustment,电子枪对中调节装置electron image intensifier,电子象增强器electron impact desorption(EID),电子轰击解吸electron impact ion source;EI source,电子轰击离子源electron induced desorption(EID),电子诱导解吸electron lens,电子透镜electron microscope,电子显微镜electron mobility detector,电子适移率检测器electron noise,电子噪声electron lperation desk of EPMA,电子探针的电子操纵台electron optical system of EPMA,电子探针的电子光学系统electron optics,电子光学electron paramagnetic resonance spectroscopy;EPR spectroscopy,电子顺磁共振波谱法 electronprobe,电子探针electron probe micro-analysis(EPMA)电子探针微分析electron probe X-ray microanalyzer,电子探针X射线微区分析仪electron spectrometer,电子能谱仪electron type rock ore densimeter,电子式岩矿密度仪electron wave length,电子波长electron-beam atomizer,电子束原子化器electron-diffraction method(EED),电子衍射法electron-energy analyzer,电子能量分析器electron-hole pairs,电子—空穴对electronic analogue-to-digital converter,电子模/数转[变]换器electronic automatic compensator,电子自动补偿仪electronic balance,电子天平electronic batching scale,电子配料秤electronic bathythermograph(EBT),电子深温计electronic belt conveyor scale,电子皮带秤electronic counting scale,电子计数秤electronic distance-meter theodolite,电子测距光学经纬仪electronic fluxmeter,电子磁通表electronic hoist[hanging] scale,电子吊秤electroinc hoist scale,电子料斗秤electronic integrating fluxmeter,电子积分式磁通表electronic level,电子水准仪electronic measuring instrument,电子测量仪器仪表electronic plane table equipment,电子平板仪electronic platform scale,电子平台秤electronic railway scale,电子轨道衡electronic sampling switch,电子采样开关electronic tacheometer,电子速测仪electronic tesing machine,电子式试验机electronic theodolite,电子经经纬仪electronic top-loading balance,电子上皿天平electronic trunk scale,电子汽车秤electrooculographic transducer[sensor],眼电图(EOG)传感器electrophoresis,电泳法electrophoresis meter,电泳仪electropolisher,电解抛光机electroretinographic transducer[sensor],视网膜电图(ERG)传感器electroscope,验电器electrosensitive printer,电灼式印刷机electrosonde,电位探空仪electrostatic actuator,静电激发器electrostatic analyzer,静电分析器electrostatic display recorder,静电显示记录仪electrostatic electron microscope,静电电子显微镜electrostatic emanometer,静电计式射气仪electrostatic instrument,静电系仪表electrostatic lens,静电透镜electrostatic microphone,静电八极透镜electrostatic printer,静电印刷机electrostatic quadrupole lens,静电四极透镜electrostatic screen,静电屏蔽electrovolumetric analysis,电容量分析(法)elemental error,单元误差elevated temperature testing machine,高温试验机elevated-zero range,零点提升范围elevation,(海拔)高度elevation of zero point of barometer,气压表零点高度elliptical polarization instrument,椭圆极化仪elliptical vibration,椭圆振动elongation,伸长率elongation rate,延伸率elution,洗脱elution chromatorgraphy,冲洗色谱法emanation survey,射气测量emanation thermal analysis,放射(性)热分析emanation thermal analysis apparatus,放射热分析仪emanometer,测氡仪;射气仪embedded strain gauge,埋入式应变计emission electron microscope,发射电子显微镜emission spectrum,发射光谱emission X-ray spectrometry,发射X射线谱法emissivity,发射率emittance of the earth's surface,地表面辐射emulsifier,乳化液槽encapsulation(Ex m),浇封(Ex m)encircling coil,环形线圈enclosed-scale liquid-in-glass thermometer,内标式玻璃温度计 END byte,结束字节end connection,连接端end of file(EOF),文件结束end-points,端点endothermic peak,吸热峰ENDSUM byte,结束总和字节endurance test,耐久性试验energizing frequency,激励频率energizing voltage,激励电压energy dispersion,能量色散energy equivalent,能当量energy filter,能量过滤器energy loss,能量损失energy olss of electron spectrometer,电子能量损失谱仪energy loss spectrometer,能量损失谱仪energy processor module,能量处理组件energy spread,能量分散engineer's operating station,工程师操作站engineer's theodilite,工程经纬仪engineering cybernetics,工程控制论enhineering simulator,工程仿真器engineering system simulation,工程系统仿真Engler viscosity,恩氏粘度enhancement effect,增强效应enveloped thermistor,密封型热敏电阻器environmental condition,环境条件environmental error,环境误差environmental factor,环境因素environmental gas analyzer,环境气体分析仪environmental influence,环境条件影响environmental monitor station,环境监测站environmental noise,环境噪声enivronmental parameter,环境参数environmental specification,环境规范environmental tset,环境试验environmental test equipment,环境试验设备enzyme substrate electrode,酶敏电极epoxy resin,环氧树脂Epstein frame,爱普斯坦方圈Epstein measuring apparatus,爱普斯坦测量装置equal precision measurement,等精密度测量equalization,均衡equalizing block,均温块equalizing orifice,平衡孔equilibrium point,平衡点equilibrium state,平衡状态equivalent a.c.resistance,等效交流电阻equivalent air volume,等效空气容积equivalent conductance,当量电导equivalent input impedance,等效空气容积 equivalent conductance,当量电导equivalent input impedance,等效输入阻抗equivalent n-th modal unbalance,第n阶振型等效不平衡谐量equivalent potential screen,等电位屏蔽equivalent sound pressure level due to inherent noise of microphone, 传声器等效噪声级equivalent uniform roughness,等效均匀粗糙度erecting telescoope,正像望远镜ergonomics,工效学erosion,侵蚀erratic motion of the moving element,运动部件的漂移运动error,误差error coefficient,误差系数evaluation standard,评定标准evaporativity,蒸发率evaporimeter,蒸发仪;蒸发表evaporograph,蒸发计evapotranspirometer,蒸散表event marker,标记装置event pulse,事件脉冲event recorder,事故[状态]记录仪evolved gas analysis(EGA),逸出气分析evolved gas analysis apparatus,逸出气分析仪evolved gas detection(EGD),逸出气检测evolved gas detection apparatus,逸出气检测器excess energy meter,超量电度表excitation,激励excitation force,激振力excitation index,激发指数exciting curent,激磁电流executive routine,执行程序exothermic peak,放热峰expanded scale,扩展标度expanded scale instrument,扩展标度尺仪表expansibility factor,可膨胀性系数expansion factor,膨胀系数expansion chamber(of liquid-in-glass thermometer),(玻璃温度计的)膨胀室expected long term stability,预期的长期稳定性expendable bathythermograph(XBT),投弃式深温计experimental intensity of scattered ion,散射离子的实验强度experimental standard deviation,实验标准偏差experimental standard deviation of the mean,平均值的实验标准偏差experimental temperature scale,经验温标experimental variance,实验方差explosion-proof electric actuator,防爆型电动执行机构explosion-proof instrument,防爆型仪器仪表explosion-proof solenoid valve,防爆型磁阀explosive limit of flammable gas,可燃气体的爆炸限explosive sound source,爆炸声源export package,出口包装exposed junction,外露端exposed junction type sheathed thermocouple,露端型铠装热电偶exposure,曝光量exposure chart,曝光曲线图exposure time,曝光时间extended rating current,扩展的额定电流exteneed rating type curent transfomer,扩展的额定型电流互感器extending extension lead,延伸型上阀盖extension lead,延长导线extension lead error(of thermocouple),(热电偶的)延长导线误差extension lead method,延长导线法extensometer,引伸计exterior package,外包装external critical resistance,外临界电阻external-convection column sensitive element,柱状外对流敏感元件external-convection ring sensitive element,环状外对流敏感元件external disturbance,外扰exteranl gear,转子齿轮external lock signal,外锁信号external reference sample,外参比试样external-scale liquid-in-glass thermometer,外标式玻璃温度计external standard method,外标法externally-piloted regulator,组合指挥器操作型自力式调节阀extra-column effect,柱外效应extraction lens,引出透镜extrapolated onset,外推超始点;外延始点extreme temperature,极端温度Fface to face dimension,端面距尺寸facsimile seismograph,传真式地震仪factory communication,工厂通信factory information protocol,工厂信息协议Fahrenheit,华氏度Fahrenheit temperature scale,华氏温标fail safe,换效安全fail tree analysis,失效树分析failure,失效failure diagnosis,失效诊断failure mechanism,失效机理failure mode,失效率failure recognition,失效识别failure valve position,阀断源位置failure cable,流线型拖缆fall time,下降时间falling coaxial cylinder viscometer,同轴圆筒下落粘度计falling sphere viscometer,落球粘度计false strain,虚假应变fanning mill anemometer,叶轮式风速表far field,远场far infra-red radiant element,远红外副射元件far infrared radiation,远红外辐射Faraday cage,静电屏蔽farinfrared spectrophotometer,远红外分光光度计fast atom bombardment,(FAB),快速原子轰击faster-than-real-time simulation,超实时仿真fatigue,疲劳fatigue characteristic,疲劳特性fatigue failure,疲劳破裂fatibue life,疲劳寿命fatigue limit,疲劳极限fatigue strain gauge,疲劳应变计fatigue testing machine,疲劳试验机fault,故障feasibility,可行性feasibility study,可行性研究feasible cooordination,可行协调feasible region,可行域feature detection,特征检测feedback,反馈feedback compensation,反馈补偿feedback control,反馈控制feedback controller,反馈控制器feedback elements,反馈元件feedback gain,反馈增益feedback loop,反馈回路feedback path,反馈通路feedback signal,反馈信号feedforward,前馈feedforward compensation,前馈补偿feedforward control,前馈控制下feedforward path,前馈通路feedover,馈越ferrodynamic galvanometer,铁磁电动系振动子ferrodynamic instrument,铁磁电动系仪表ferrograph,铁磁示波器FET gas transducer[sensor],场效应(管)湿度传感器fiber communication,光纤通信fiducial error,引用误差fiducial value,引用值;基值field,字段;现场field balancing,现场平衡field balancing equipment,现场平衡设备field coil,励磁线圈field controller,磁场控制器field data,现场数据field desorption(FD),场解吸field emission electron image,场发射电子象field emission gun,场发射电子枪field emission microscope,场发射显微镜field ion emission microscope,场离子发射显微镜field ionization source;FI source,场电离源field test,现场试验field of view,视场field rdliability test,现场可靠性试验field stop,视场光栏field sweeping,场扫描field-frequency lock,场频锁fieldbus,现场总线fieldbus control system(FCS),现场总线控制系统filament image,灯丝象filar suspended galvanometer,悬丝式检流计file,文件;文卷file maintenance,文卷维护fill factor,占空因子;填充率filled system thermometer,压力式温度计filled thermal system,充灌式感温系统film recording thermograph,照相温度(表)film sample,薄膜样品film varstor,膜式电压敏电阻器filter,滤光计;过滤器;滤波器;滤光板;滤线板filter device,滤光装置filtered electron image,过滤电子象filtered electron lens,过滤电子透镜final controlling element,终端控制元件;执行器final state,终态final controlling element,终端控制元件;执行器final state,终态final temperature,终了温度终止温度Fineman nephoscope,法因曼测云器finte automaton,有限自动机fire behaviour,着火性能fire integrity,整体着火性fire resistance,耐火性 fire stability,对火稳定性 firmware,固件 fish finder,鱼探仪 fitting,管件five-component borehole magnetometer,井中五分量磁测井仪fixed core,定铁芯fixed(measuring)instrument,固定式(测量)仪表fixed points method of calibration,定点法标定fixed resistance input type volt ratio box,定阻输入式分压箱fixed resistance output type volt ratio box,定阻输出式分压箱fixed set point control,定值控制fixed set point control system,定值控制系统rixed-based natural frequency,固定基础固有频率flag,标记flame emission spectrometry,火焰发射光谱法flame ionization detector(FID),火焰离子化检测器flame photometric detector(FPD),火焰光度检测器flame proof enclsoure(Ex d),隔爆外壳(Ex d)flame temperature detector,火焰温度检测器flange pressure tappings,法兰取压口flanged ends,法兰连接端flangeless ends,无法兰连接端flangeless valve,无法兰阀flashing,闪阀flaw echo,缺陷反射波flaw resolution,缺陷分辨力flaw sensitivity,缺陷灵敏度flexible disk,软磁盘flexible manufacturing system,柔性制造系统flexible rotor,柔性转子flexural critical speed,挠曲临界转速flexural principl mode,挠曲主振型flicker,闪烁float,浮子float and cable level measuring device,浮标和缆索式液闰测量装置float barograph,浮子气压计float level measuring device,浮子液位测量装置float level reguator,浮子型液位调节阀float level transducer[sensor],浮子—干簧管液位传感器float tide gauge,浮子式验潮仪floating accelerometer,重力式测波仪floating ball,浮置输入floating output,浮置输出floppy disk drive,软磁盘机flow chart,流程图表flow coefficient,流量系数flow conditioner[straightener],流动调整器[整直器]flow control,流量控制flow corrector,流量修正器flow diagram,流程图flow elbow,流量弯管flow measurement calibration device,流量测量校准装置flow measuring device,流量测量装置flow nozzle,流量喷嘴flow profile,流动剖面flow rate of mobile phase,流动相流速flow sihnal,流量信号flow stabilizer,流量稳定器flow switch,流量开关flow to close,流关flow to open,流开 flow transducer[sensor],流量传感器flowmeter,流量计flow-rate,流量flow-rate range,流量范围fluctuation,波动(度)fluid damping galvanometer,液体阻尼振动子fluidic flowmeter,射流流量计fluorescence,荧光修正fluorescence detector,荧光检测器fluorescence effect,荧光效应fluorescent image,荧光象flurescent magnetic partcle,荧光磁粉fluorescent magnetic particle inspection machine,荧光磁粉探伤机fluorescent penetrant festing method,荧光渗透探伤法fluorine plastic,氟塑料fluorine rubber(viton),氟橡胶fluorometer,荧光计 flush mounted(pressure)gauge,,嵌装压力表flutter,颤振flux constant,磁通常数flux meter,磁通表flux of radiation,辐射通量fluxgate compass,磁通门罗盘fluxgate magnetometer,磁通门磁力仪;磁通门磁强计fluxmeter,磁通表fluxmeter calibrator,磁通表校验仪focal distance,焦距focal plane,焦平面focal point,焦点focus,焦点focus size,焦点尺寸focus-to-film distance,焦距focusing,聚焦focusing type probe,聚焦探头fog-gauge,雾量器foil strain gauge,箔式应变计folding chart[paper],折叠式记录纸follow-up control,随动控制follow-up pointer,从动针food analyzer,食品分析仪force,力force-balance acceleration transducer,力平衡式加速度传感器force-balance accelerometer,力平衡式加速度计force convection,强近对流force standard machine,力标准机force transducer[sensor],力传感器forced vibration,强迫振动;受迫振动foregraound,前台 foreground processing,前台处理foreground program,前台程序form factor,波形因数Fortin barometer,福丁气压表forward channel,正向信道Foundation Fieldbus(FF),基金会现场总线;FF总线four-terminal standard resistor,四端(钮)标准电阻器Fourier transform,傅里叶变换Fouier transform ion cyclotron resonance mass spertrometer (FT-ICR-MS), 傅立叶变换离子回旋共振质谱计Fourier transform infrared spectrometry,傅立叶变换红外光谱法Fourier transform spectrometer,傅里叶变换光谱仪fracture toughness,断裂韧性fragment ion,碎片离子fragmentation,碎裂过程frqgmentation pattern,碎裂图型frame,帧 framework,框架free falling STD profilinge system,自返式温盐深剖面仪free field,自由声场free field correction curves,自由场修正曲线free-field frequency response of microphone,传声器自由声场频率响应free feild reciprocity calibration,自由声场互易校准free-field sensitivity of microphone,传声器自由声场灵敏度free induction decay signal;FID signal,自由感应衰减信号free oscillating period,自由振动周期free swing of pendulum,摆锤空击free vehicle respirometer,活动式海底生物呼吸测量器free vibration,自由振动freezing heat,凝固热freezing point,凝固点frequency,频率frequency-amplitude characteristic,幅频特性frequency analysis,频率分析frequency analyzer,频率分析仪frequency band,频带frequency distrbution,频率分布frequency division multiplexing,频分多路传输frequency domain,频域frequency domain analysis,频域分析frequency domain method,频域法frequency domain model reduction method,频域模型降价法frequency index,频率指数frequency measurement by comparison with time scale,时标比较法测频frequency measurement by digital meter,用数字频率计测频frequency measurement by Lissajou's figure,用李沙育图形测频frequency measurement by stroboscope,闪光测频frequency measurement by vibrationg reed indicator,用舌簧频率计测频frequency meter,频率表frequency modulation(FM),频率周制,调频frequency of the natural hydraulic mode,液压固有频率frequency output,频率输出frequency-phase characteristic,相频特性frequency response,频率响应frequency response characteristics,频率响应特性(图)frequency reponse locus,频率响应轨迹图frequency response of microphone,传声器频率响应frequency response range,频率响应范围frequency resonse tracer,频率响应显示仪frequency shift keying(FSK),频移键控frequency shift magnetometer,频移磁强计frequency sounding instrument,频率测深仪frequency spectra induced polarization instrument,频谱激电仪frequency stabilization,频率稳定frequency sweeping,频率扫描frequency-temperature coefficient,频率—温度系数Fresnal diffraction string,费涅尔衍射条纹friction bezel ring,压紧盖环friction error,轻敲位移friction velocity,磨擦速度front end processor,前端处理机frontal chromatography,迎头色谱法frost point hygrometer,霜点湿度计(表)full bridge measurement,全桥测量full capacity trim,全容量阀内件full-load test,满载试验full scale flow-rate,满标度流量full-screen editing,全屏莫编辑full-screen processing(FSP),全屏幕处理full-wave logger,声波全波列测井仪fully developed velocity distrbution,充分发展的速度分布fully insulated current transormer,全绝缘电流互感器fully rough trbulent flow,充分混杂紊流function,功能function analysis,功能分析function block,功能块function key,功能键function module,功能模块function type optic-fibre temperature transducer,功能型光纤温度传感器functional block,功能块functional decomposition,功能分解functional insulation,功能绝缘functional similarity,功能相似functional simulation,功能仿真fundamental frequency,基本频率fundamental method of measurement,基础测量法fundamental natural mode of vibration,基本固有振型fundamental period,基本周期fundamental wave,基波funnel-shaped mud viscometer,漏斗式泥浆粘度计furnace for reproduction of fixed points,定点炉furnace for verification use,检定炉fuzzy control,模糊控制fuzzy controller,模糊控制器fuzzy decision,模糊决策fuzzy game,模糊对策fuzzy information,模糊信息fuzzy logic,模糊逻辑Ggain,增益gain margin,增益裕度gain-crossover frequency,增益交越频率galvanic cell,原电池galvanometer,检流计galvanometer gecord type strong-motion instrument,电流计记录式强震仪galvanometer with optical point,光点式检流计game theory,对策论;博弈树gamma directioned radiometer,伽玛定向辐射仪gamma processing image,处理象gamma radionmeter in borehold,井中伽玛辐射仪gamma-ray detection apparaturs,射线探伤机gamma ray level measuring device,伽马射线液位测量装置gamma(ray)spectrometer,伽玛能谱仪gamma-rays,射线gamma ray logger,伽玛测井仪gamma sampling radiometer of banded screen,带屏伽玛取样加射仪gamma scintillator radiometer,伽玛闪烁辐射仪gamma spectrometer in borehold,井下伽玛能谱仪gamma-spectrometry,伽玛测量gas analyzer,气体分析器gas chromatograph,气相色谱仪gas chromatograph-mass spectrometer(GC0MS),气相色谱—质谱联用仪接口gas chromatography,气相色谱法gas chromatorgaphy-mass(GC-MS),气相色谱—质谱法gas cylinder regulator,气瓶减压器gas densitometer,气体密度计gas-discharge source,气体放电源gas-enclosed pressure gauge,气密引压式验尚潮仪gas generator,气体发生器gas laser,气体激光器gas-liquid chromatography,气液色谱法gas proportional detector,气体正比检测器gas pump thermocouple,抽气式热电偶gas purged pressure recording gauge,补气引压式验潮仪gas sensing electrode,气敏电极gas-sensitive element,气敏元件gas sensor,气敏元件gas-solid chromatography,气固色谱法gas thermometer,气体温度计gas transducer[sensor],气体传感器gastrointestinal inner pressure transducer[sensor],胃肠内压传感器gate,闸门gate-type lowmeter,闸门式流量计gate valve,闸阀gateway,网间连接器gauge block,量块gauge circuit,应变计[片]电路gauge factor,应变计灵敏系数gauge length,标距长度gauge pressure,表压gauge pressure transducer[sensor],表压传感器gauge resistance,应变计(片)电阻Gauss optics,高斯光学Gaussian integration method,高斯求积法gear reducer,减速器Geiger type vibrograph,盖格尔式测振仪gel chromatography,凝胶色谱法general-purpose(pressure)gauge,一般压力表general purpose strain gauge,常温应变计general system theory,一般系统理论generalization,通用化generalized modeling,广义建模generation function,生成函数geodetic instrument,大地测量仪器geologic compass,地质罗盘仪geological stereometer,地质立体量测仪geomagnetic electrokinetograph(GEK),地磁场电磁海流计geometric aberration,几何象差geometric centre of the dial,度盘几何中心geostationary meteorological satellite,地球同步气象卫星germanium thermometer,锗电阻Gershum tube,格森管shost echo,假反射波,假伤波ghost peak,假峰glass circle,玻璃电极global analysis,整体分析global data base,全球数据库global optimum,全局最优global radiation,总辐射globe valve,球形阀glucose enzyme transducer[sensor],酶(式)葡萄糖传感器glutamate(glutamic acid)microbial transducer[sensor],微生物谷氨酸传感器grade,级;等grade I standard dynamometer,一等标准测力计grade II standard load calibrating machine,二等标准测力机grade IIIstandard dynamometer,三等标准测力计graded-L operation,分级L操作Grader-L signals(GL),分级L信号gradient error(of bath),(槽的)梯度误差gradient flux-gate magnetometer,磁通门磁力梯度仪gradient superconducting magnetometer,超导磁力梯度仪graduated range,刻度范围graph search,图搜索graph theory,图论graphic library,图形库graphic panel,全模拟盘grating displacement transducer,光栅式位移传感器grating monochromator,光栅单色仪grating spectrograph,光栅摄谱仪gravimeter,重力仪gravitational balancing machine,重力式平衡机gravity,重力gravity anomaly,重力异常gravity corer,重力式取样管gravity correction,重力修正gravity gradient survey,重力梯度测量gravity gradiometer,重力梯度仪gravity horizontal gradient survey,重力水平梯度测量gravity nut,重心铊gravity platform,重力平台gravity profile,重力剖面gravity survey,重力测量gravity vertical gradient survey,重力垂向梯度测量gravity-piston type corer,重力活塞式取样管graybody,灰体gray scale,灰度grid,控制极;栅极grid-controlled X-ray tube,栅控X射线管grid lines device,格线装置gridnephoscope,栅状测云器grip,夹头ground electrochemical extractor,地电化学提取法仪器ground electromagnetic instrument,地面电磁法仪器ground gamma spectrometer,地面伽玛能谱仪ground gravity survey,地面重力测量ground instrument,地面仪器ground noise,本底噪声ground pulse electromagnetic instrument,地面脉冲电磁仪ground receivint station,地面接收站ground visibility,地面能见度ground X-ray fluorimeter,地面X射线荧光仪grounded junction,接地端grounded noise,接地噪声groupof an instrument for explosive atmosphere,防爆仪表类别guarded input,保护输入guidance system,导向系统gyro balancing machine,陀螺测斜仪。
水下悬跨管道动力响应分析
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文献[ ] 3 采用谱方法分析了悬跨海底管线对随机地震
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维普资讯
第 8期
包 t东等 :水下悬跨管道动力 响应分析 3
前悬架硬点优化设计
1 引言
2 前悬架参数分析
悬架系统是汽车的重要总成之一,影响着车辆的操纵稳定 2.1 前悬架模型建立
性和平顺性。车轮定位参数一般会在汽车行驶时随着车轮受力和 车身运动而发生变化,并且定位参数的变化能反映悬架性能的优 劣。所以,要求定位参数在行驶时的变化范围不能过大[1-2]。
对某公司提供的 CATIA 双叉臂独立悬架模型进行关键点 测量,如图 1 所示。在 ADAMS/Car 中建立前悬架模型时,要对模 型进行相应的简化,除了弹性零件,将悬架零部件中的其它零件
来稿日期:2017-11-24 基金项目:国家自然科学基金(51178231) 作者简介:宋年秀,(1963-),男,青岛人,博士研究生,硕士生导师,教授,主要研究方向:汽车可靠性检测;
张 利,(1992-),女,山东临沂人,硕士研究生,主要研究方向:载运工具运用工程
第4期
宋年秀等:前悬架硬点优化设计
机械设计与制造
第4期
58
酝葬糟澡蚤灶藻则赠 阅藻泽蚤早灶 驭 酝葬灶怎枣葬糟贼怎则藻
圆园18 年 4 月
前悬架硬点优化设计
宋年秀,张 利,于明晓
(青岛理工大学 汽车与交通学院,山东 青岛 266520)
摘 要:针对前悬架性能的优化问题,提出一种基于近似模型并用响应面法和改进 NSGA-II 遗传算法相结合的方法对前 悬架进行优化设计。利用 ADAMS/Car 建立双叉臂前悬架动力学仿真分析模型,在 Insight 中对悬架的硬点参数进行灵敏 度分析,选择出灵敏度大的设计参数,并建立响应面近似模型,运用改进 NSGA-II 算法对悬架进行硬点优化设计。结果表 明,优化后的前轮定位参数在车轮跳动过程中的变化量明显减小,悬架的性能得到很好的提高,该设计方法实现了悬架 硬点的优化,为悬架的优化设计提供了依据。 关键词:悬架性能,响应面法,改进遗传算法,近似模型,灵敏度分析 中图分类号:TH16;U463.33 文献标识码:A 文章编号:员园园员-3997(圆园18)04-0058-03
非线性汽车悬架的混沌特性
非线性汽车悬架的混沌特性任成龙(南京工程学院车辆工程系,江苏南京211167)收稿日期:2009-11-16基金项目:江苏省“六大人才高峰”项目(07-D-014);南京工程学院重大科研项目(KXJ07066)通信作者:任成龙(1979-),男,辽宁绥中人,硕士,讲师,主要从事车辆振动检测理论与状态智能监测研究.E-mail :rencill@摘要:通过数值仿真和实验,研究了非线性汽车悬架的混沌特性.建立了路面双频拟周期激励作用下的单自由度汽车悬架模型,通过数值仿真,给出了悬架振动的时间历程曲线、自功率谱密度图形和Poincare 截面,从理论上说明汽车悬架振动是混沌的.进行振动实验,获取实验汽车悬架的振动数据,对其计算了一阶固有频率和混沌参数如关联维、Kolmogorov 熵和最大Lyapunov 指数,从而验证了汽车悬架振动的混沌特征.为汽车悬架的优化设计和建立悬架隔振性能混沌评价新方法提供了理论依据.关键词:悬架;混沌;仿真;实验中图分类号:U463.33;O32文献标识码:A文章编号:1672-9102(2010)02-0099-03滞后非线性广泛存在于实际工程振动系统中,汽车悬架作为滞后非线性系统,具有强时变性、强非线性、强非平稳性的动力学特性,且其非线性因素在一定的载荷、激励和频域内影响十分突出[1-2].滞后非线性系统的多值性和非光滑性导致系统中非常容易产生分岔和混沌等复杂的非线性动力学行为,孟泉等[3]研究了多频周期激励作用下汽车悬架系统的分岔特性;贾启芬等[4-5]以悬架的线性非线性动力系统出发,用非线性理论KB 法得到系统的幅频响应函数呈现丰富的非线性特性;杨绍普[6-7],方明霞[8-9]等通过仿真说明具有滞后非线性的汽车悬架系统中存在着混沌运动.汽车悬架是非常复杂的非线性系统,研究这类系统的建模并进行数值仿真,分析其非线性动力学行为可能出现的混沌现象,将为悬架系统的设计及汽车的动态设计和结构改进提供重要的理论依据和保证,并有助于提高对非线性系统本质的认识.本文以路面双频拟周期激励作用下的具有滞后非线性的单自由度汽车悬架为研究对象,通过数值仿真,给出了汽车悬架振动的时间历程曲线、自功率谱密度图形和Poincare 截面,从理论上给出了悬架振动发生混沌的可能性.同时,采用制动法,运用4PLD 型平板制动实验台获取了某越野车在3种不同状态下的悬架振动数据,又采用按压车体法,获得了某铃木、本田、吉利和奥迪轿车在初始悬架状况下的悬架振动数据,对其计算了一阶固有频率和混沌特征参数如关联维、Kolmogorov 熵和最大Lyapunov 指数,验证了汽车悬架振动的混沌特性,将为探讨对汽车悬架隔振性能进行混沌评价提供理论依据.1汽车悬架振动的仿真研究本文以受双频拟周期路面位移激励下的单自由度1/4汽车悬架模型为研究对象,得到系统的运动微分方程为M x 咬+k 1(x-x 0)+F =0.(1)式中,M 为车体质量,k 1为车体刚度,F 为滞后非线性阻尼力,用位移和速度三次方的数学模型描述,x 0为路面位移激励,x 为车体垂直位移.设:y=x -x 0;x 0=A 1sin Ω1τ+A 2sin Ω2τ,Ω1,Ω2不可有理通约;F=k 2(x -x 0)3+c 1(x 觶-x 觶0)+c 2(x觶-x 觶0)3;其中,k 2为系统的非线性度系数,c 1,c 2为系统的非线性阻尼系数.湖南科技大学学报(自然科学版)Journal of Hunan University of Science &Technology (Natural Science Edition )第25卷第2期2010年6月Vol.25No.2Jun.201099则式(1)可化为y+ω2y+B 1y 3+B 2y +B 3y 3=F 1sin Ω1τ+F 2sin Ω2τ.(2)其中,ω2=k 1M ,B 1=k 2M ,B 2=c 1M ,B 3=c 2M,F 1=A 1Ω21,F 2=A 2Ω22,系统(2)为一滞后非线性系统.设系统基本物理参数如下:M =500kg ,k 1=250000N/m ,k 2=-400000N/m 3,c 1=500N ·s/m ,c 2=-50N ·s 3/m 3.通过数值模拟,并利用四阶定步长龙格-库塔法对式(2)进行积分,得到当路面双频拟周期激励振幅为A =0.16m 时系统的时间历程曲线、自功率谱密度和Poincare 截面图,分别如图1,图2和图3所示.从图1可知,时间历程曲线是非周期的,无规律,有随机运动的特点;由图2可知,自功率谱密度图形定常且连续,出现类似噪声的背景和宽峰,是混沌运动的特征;由图3可知,Poincare 截面充满相空间中的某一部分,分维较明显,且具有自相似结构,表现出奇怪特性.同时,对仿真所得数据进行混沌特征参数计算,得到系统的最大Lyapunov 指数(记为L y m ax )L y m ax =0.536>0,关联维D 2=0.648,不为整数,从而可知此时汽车悬架的振动处于混沌运动状态,进而从理论上证明汽车悬架系统的运动能够进入混沌状态.2汽车悬架振动的实验研究2.1汽车悬架振动实验采用制动法,运用4PLD 型汽车制动-悬架隔振效率实验台,在车速10km/h 时,分别获得具有钢板弹簧非独立悬架的某越野车在初始状态、中等状态和最差状态时汽车制动过程中的悬架振动数据.采用按压车体法,获得具有麦弗逊式独立悬架的某铃木、本田、吉利和奥迪4辆轿车在初始状态下的悬架振动数据.传感器分别布置于悬架(靠近车轮处)与悬架附近车架相应位置,均采用磁座与被测点相接,按压汽车前保险杠,同时运用QLV 多功能虚拟信号分析仪记录振动数据.制动法是利用紧急制动时汽车轴载分配值的冲击性转移,激发出悬架-车轮系统的响应信号;按压车体法是利用人工按压车体对悬架-车轮系统激励,激发悬架-车轮系统的响应信号,其共性实质都是利用拟脉冲激励在频域中的有限带宽性质[10],用足够大能量的激励作用于悬架-车轮系统,检测拟脉冲激励过程中该系统的振动响应信号.拟脉冲激励悬架振动检测框图如图4所示.2.2汽车悬架的混沌特征分析关联维能够定量描述事物内部结构的复杂程度,Kolmogorov 熵实际代表了系统信息的损失程度,它们反映了混沌系统中奇异吸引子的整体变化情况,适合于描述非稳态非线性动力学系统的混沌性质,Kolmogorov 熵(记为K 熵)K 熵>0对应于系统作混沌运动,关联维D 2>2或不为整数也对应于系统作混沌运动.Lyapunov 指数反映了系统对初值的敏感性,是目前判断混沌的最可靠的一种定量方法,适用于随机动力系统混沌运动的判别,若最大李雅普诺夫指数L ym ax >0,则系统一定存在混沌.对于实测的汽车悬架振动数据,首先进行相空间150010005000-500-1000-1500500100015002000图1时间历程曲线图Fig.1Time history curve采样点数位移/m m501001501098765频率/Hz功率谱/d B图2自功率谱密度图Fig.2Self-power spectral density figure150010005000-500-1000-1500-1500-1000-500050010001500特征向量1特征向量2图3Poincare 截面图Fig.3Poincare section图4拟脉冲激励悬架振动检测框图Fig.4Schematic diagram of suspension vibration detection underquasi-impulse excitation100Chaotic characteristics of nonlinear automobile suspensionREN Cheng-long(Department of Vehicle Engineering ,Nanjing Institute of Technology ,Nanjing 211167,China )Abstract :The chaotic characteristics of nonlinear automobile suspension were researched by numerical simulation and experiment.Thesingle degree of freedom automobile suspension model ,which was subjected to the road random excitation ,was built.The time history curve ,self-power spectral density figure and Poincare map were given by numerical simulation.It is confirmed that the vibration of automobile suspension is chaotic.The vibration curves of the automobile suspension are obtained by experiment.The first order nature frequency and the chaos characteristics parameters such as correlation dimension ,Kolmogorov entropy and maximum Lyapunov exponent are calculated.The chaotic characteristics of automobile suspension vibration are verified.The basis for optimization design of automobile suspension and the establishment of a new suspension vibration isolation performance chaotic evaluation method is provided.Key words :suspension ;chaos ;simulation ;experiment重构并确定最小嵌入相空间维数[11];其次计算关联积分,并通过线性拟合求得关联维D 2值;然后计算求得K 熵和L ym ax 值,如表1,表2所给.同时,可计算汽车悬架振动的一阶固有频率,也如表1,表2所给.由表1,表2可知:1)具有非独立悬架的实验越野车,在初始、中等和最差3种状态时,其悬架振动均具有混沌特性;2)具有独立悬架的实验轿车,其悬架振动也均具有混沌特性;3)目前汽车悬架性能的评价参数一般为固有频率和吸收率,而由于实验汽车悬架振动的一阶固有频率与混沌特征参数的一致对应性,即改变实验汽车悬架状态,其一阶固有频率减小13.7%,而对应的混沌特征参数D 2,K 熵和L y m ax 值都随之增大110.9%,84.0%和71.5%,故可考虑采用混沌参数来评价汽车悬架的振动特性.3结论1)建立了路面双频拟周期激励作用下的单自由度汽车悬架模型,通过数值仿真,从理论上说明汽车悬架系统运动能够进入混沌状态.2)进行了汽车悬架振动实验,计算了悬架振动的一阶固有频率和混沌特征参数,验证了实验汽车的悬架振动均具有混沌特性.3)研究了非线性汽车悬架的混沌特性,将为汽车悬架系统的设计和改进提供依据,并为进行汽车悬架系统隔振性能的混沌评价提供了理论基础.参考文献:[1]Kurimoto M ,Yoshimura T.Active suspension of passenger cars using sliding mode controllers (based on reduced models )[J].InternationalJournal of Vehicle Design ,1998,19(4):402-414.[2]Kim C ,Ro P I.A sliding mode controller for vehicle active suspension systems with non-linearties[J].Pro Intn Mech Engrs ,1998,212(part D ):79-92.[3]孟泉,王洪礼.汽车系统的分岔研究[J].汽车工程,2004,26(1):50-53.Meng Q ,Wang H L.A study on bifurcations of vehicle system[J].AutomobileEngineering ,2004,26(1):50-53.[4]贾启芬,于雯,刘习军,等.汽车悬架系统的分段线性非线性振动机理的研究[J].工程力学,2005,22(1):88-92.Jia Q F ,Yu W ,Liu X J ,et al.Dynamic characteristics of bilinear suspension system of vehicles[J].Engineering Mechanics ,2005,22(1):88-92.[5]卢胜文,贾启芬,于雯,等.汽车多自由度悬架的非线性振动特性[J].应用力学学报,2005,22(3):461-465.Lu S W ,Jia Q F ,Yu W ,et al .Nonlinear dynamic characteristics of vehicle suspension system with multi-degrees of freedom[J].ChineseJournal of Applied Mechanics ,2005,22(3):461-465.[6]杨绍普,李韶华,郭文武.随机激励滞后非线性汽车悬架系统的混沌运动[J].振动、测试与诊断,2005,25(1):22-25.Yang S P ,Li S H ,Guo W W.Chaos in vehicle suspension system with hysteretic nonlinearity[J].Journal ofVibration ,Measurement &Diagnosis ,2005,25(1):22-25.[7]李韶华,杨绍普.拟周期激励下滞后非线性汽车悬架的混沌[J].振动与冲击,2003,22(3):61-65.Li S H ,Yang S P.Chaos in suspension system with hysteretic nonlinearity under quasi-period excitation[J].Journal of Vibration and Shock ,2003,22(3):61-65.[8]方明霞,谈军,冯奇.悬架迟滞非线性特性对汽车平顺性的影响[J].振动与冲击,2008,27(11):67-70.Fang M X ,Tan J ,Feng Q.Influence of hysteretic nonlinear property of suspension on automobile ride comfort[J].Journal of Vibration andShock ,2008,27(11):67-70.[9]肖海斌,方明霞.四自由度汽车迟滞非线性系统的混沌[J].动力学与控制学报,2008,6(4):377-380.Xiao H B ,Fang M X.Chaos in nonlinearity considered 4-degree automobile system[J].Journal of Dynamics and Control ,2008,6(4):377-380.[10]汪洋,杨云志,张弛.拟脉冲激励及其共振响应技术的车辆工程运用[J].公路与汽运,2008(3):18-21.Wang Y ,Yang Y Z ,Zhang C.Application of quasi-impulse and syntony response in vehicle engineering[J].Highways and Automotive Applications ,2008(3):18-21.[11]张雨,任成龙.确定重构相空间维数的方法[J].国防科技大学学报,2005,27(6):101-105.Zhang Y ,Ren C L.The methods to confirm the dimension of re-constructed phase space[J].Journal of National University of DefenseTechnology,2005,27(6):101-105.表1某越野车不同悬架状态下的振动参数Tab.1Vibration parameters of an off-road jeep in different suspension states悬架工况D 2K 熵L y m ax 一阶固有频率/Hz初始状态中等状态最差状态0.3210.5360.6770.5260.8640.9680.2350.3160.4031.2761.1451.101表2实验轿车初始悬架状态下的振动参数Tab.2Vibration parameters of test car in initial suspension state实验轿车D 2K 熵L y m ax 一阶固有频率/Hz铃木本田吉利奥迪0.3540.3160.1740.2671.3481.2671.3741.2390.3830.4910.4310.3751.4161.3101.8041.387101。
悬索桥主缆线形解析方程解及应用
悬索桥主缆线形解析方程解及应用第22卷第3期2005年 6 月文章编号工程力学ENGINEERING MECHANICS Vol.22 No.3 June 2005邹振祝1,2(1. 哈尔滨工业大学航天工程与力学系陈伟22.石家庄铁道学院土木分院, 河北石家庄050043) 摘要弹性伸长对主缆线比重影响的计算模型óé±ì??t?μ?a?¼?a3?¸??μ线形坐标都可以用于悬索桥设计与施工计算悬索桥中图分类号解析方程A有应力索长加劲梁按考虑和不考虑主缆通过引入一个参数u(shu=dy/dx)ò??×àí??¶?o¼º¨1y??±?2?¸yu来确定主缆算例结果表明两种计算模型收敛速度较快SOLUTION OF MAIN CABLE SHAPE EQUATIONS OF A SUSPENSIONBRIDGE AND ITS APPLICATION*ZHANG Zhi-guo1,2 , ZOU Zhen-zhu1,2 , ZHAO Yu-cheng2 , CHEN Wei2(1. Department of Astronautics and Mechanics, Harbin Institute of Technology, Harbin 150001, China;2. School of Civil Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043, China)Abstract: Analytic parameter equations for the main cable curve of a suspension bridge are derived. Calculation models taking into account the influence of its elastic elongation due to its weight and neglecting the elongation are established. A set of non-linear equations result after incorporating boundary conditions. The equations are solved with quasi-Newton method. A formula is derived for the main cable length of a suspension bridge in free stress or stressed state with integration method. The calculation result shows that the two calculation models enjoy rapid convergence and high precision, and are applicable to the design and construction control of suspension bridges.Key words: suspension bridge; main cable; analytic equation;stress-free cable length; stressed cable length1 引言悬索桥是由主缆等构成的组合结构体系[1]锚碇吊索à??Tó|á|3¤?è°°?¤??µ?oº±¸??μ??¾′???à?°2×°?÷目前抛物线法[1~4]?×·¨?ù?¨?÷à?×?è·è·?¨??3é??11D?ê?·òa?÷àD??±?¼¼°?¹3·??³′¹??µ11¹??μμ¹?¸Àµ|²1??μDü?÷??3éD?ê?è·?¨?÷2003-07-11作者简介男男男陈伟(1971)2003-12-11副教授教授副教授o¼′??¶?′¼¸µo1¤3¹μ??D??.从事断裂力学和桥梁计算理论的研究(E-mail:******************.cn)从事固体力学的研究梁得到的索形是抛物线但精度不高悬链线索元递推法[6~9]是将加劲梁吊点间索段由于只受沿弧长方向均布的主缆自重荷载而呈悬链线可以建立相邻索段间的递推关系该法精度较高本文将主缆自重看作是沿弧长均布吊索并分别按考虑和不考虑主缆弹性伸长对主缆线比重影响然后给出了确定主缆水平张力和线形坐标的计算方法该法由微元力学平衡关系推得收敛快为悬索桥主缆线形和索长计算提供了一种实用的求解方法(1) 主缆索绝对柔性不能承受弯矩即主缆材料的应力应变关系是线弹性的其它恒载(用W表示)μ??½°?à°???÷éèê?μè??·??ò?ù?è·?2?óéóú??3?1??μ³?±¸?μxoy的原点定在主缆对称中心由竖直方向的平衡可得主缆曲线微分方程为H为主缆拉力的水平分量其在主缆内各处均相等令b=W/H (2)式(1)改写成y′(x)=shu (4) 将式(4)代入式(3)dx=chu1chuachu+bdu=b?1+mchudu (5)式中代表主缆自重与除主缆自重外的其它恒载之比积分式(5)Φ(u,m)=u1mexp(u)+1??m2m?lnm?m2mexp(u)+1+?m2由式(4)得dy=shudx=shu?chub(1+mchu)du (7)积分式(7)D?éóé±ì??tè·?¨è?í?1f)»??aμ?¸?L(跨长之半)待求的是HD1ò??aO点边界条件x=0分别代入方程(6)和(8)D1x=1b*Φ(u,m)?Φ(0,m)] (9a) y=111+ma(chu?1+mln1+mchu ) (9b) 支点B处有边界条件x=L代入式(9)得174 工程力学Φ(uL,m)?Φ(0,m)=bL (10a) chuL?1+1mln1+m1+mchu=af (10b) L联立以上两式其中仅含H和uL两个未知数(H隐含于a因而解是唯一的迭代初值取抛物线理论的近似计算值求出了Hb已知比如要确定成桥状态吊点的纵坐标得到一个非线性方程再将ut代入式(9b)重复这一过程这里的非线性方程可以采用对分法[10]求解uL]?òê?á2?ù?èoü?ì?éò?·D??2??è??DDμ?±???¸??¿»??aH的条件下D1和端点未知参数u0然后再按上述方法求出主缆吊点坐标已知H?aà?2??ù?êê?Dü?÷??3éD??íò?íêè?è·?¨??á?oíê?1¤?Dμ?ò÷òa2?êy?ùòê?·òa?ú?÷àá|H和端点参数u确定后下面仅按中跨推导计算公式可知弧微分公式为得ds=1b?ch2u1+mchudu (12) 对于中跨对应x=0和x=L的参数u分别为u0=0和uL(注意边跨u0≠0)得中跨主缆有应力长的一半为E为索材弹性模量T为主缆张力万方数据得dss0=d1+T/(EA)(14)由于悬索只承受拉力可得T=H+(y′)2=Hchu (15)将式(12)和式(15)代入式(14)得dsch2udu0=b(1+mchu)(1+εchu)(16)积分式(16)s10=b(m?ε),*Φ(uL,ε)?Φ(u0,ε)+(17) ?*Φ(uL,m)?Φ(u0,m)+-由于u0和uL已在前面求出注意这里的无应力索长是精确值即将式(14)按级数展开ds0=[1?T/(EA)]ds则索段伸长量为得εch3d(?s)=b?u1+mchudu积分上式?s=εauL?u02+sh2uL?sh2u04(19) ?1m(shu1L?shu0)+m[Φ(uL,m)?Φ(u0,m)]}则中跨主缆无应力半长的一阶近似为一阶近似的无应力索长较精确值小有u0=0μ?2?ê§ò?°?D?3 考虑主缆弹性伸长对主缆线比重的影响3.1 主缆线形解析方程解上述推导中但实际中一般已知的是主缆无应力状态下的自重荷载集度q0?½´·¹3¤?¾»?o·ˉ?¶??¼·q0减小到q´′º?μ?DÀ?½½´D?2?¸y²?3¹沿弧长的自重荷载集度为q0?½´y±??aA假设图1中有应力索微段长为ds设E为主缆索弹性模量则由虎克定律有受力前后主缆微段质量保持不变q0ds0=qds (22)由式(21)得q=q0/[1+T/(EA0)] (23) 取主缆微段分析所以由水平平衡仍得主缆水平张力H处处相等但此时主缆自重荷载集度q应由式(23)表示得Hd2yq0dsd2x=1+T/(EA?+W (24) 0)dx采用与前面相似的变换整理得dx=(1+εchu)chub(1+nchu)du (25)式中bε=H/(EA0)积分式(25)得dy=(1+εchu)shuchub(1+nchu)du (27)积分式(27)得y=1εmmbn[2ch2u+nchu?n2ln(1+nchu)+D1] (28)式(26)和式(28)就是考虑主缆弹性伸长时的线形方程D1为积分常数3.2 主缆线形求解方法求解过程同前节边界条件与前节相同可确定积分常数D代回后u=uLy=f¶?¼·?a?£?¾²¨[10]求解可由方程(29)依前节过程确定主缆吊点坐标3.3 主缆长度计算将式(4)和(25)代入式(11)得s=1u?u0sh2uLbn,ε(L2+?sh2u04 (31) +mn*shuL?shu0+Φ(u0,n)?Φ(uL,n)]}将式(30)和式(15)代入式(14)得s10=bn[shuL?shu0+Φ(u0,n)?Φ(uL,n)] (33) 同理?s=εsh3uLbn,ε(shu?sh3uL?shu0+03)+mu?u0sh2uL?sh2u0nL2+4) (34) +mn2[shu0?shuL+Φ(uL,n)?Φ(u0,n)]} 将式(31)和式(34)代入式(20)¸?(31)和式(33)计算结果的2倍从以上推导可以看出这里列出这些公式只是为了比较说明4 算例某两支点等高悬索桥[6]吊索间距12m加劲梁等其余恒载集度W=200kN/m索材弹性模量E=2.0跨中矢高f=6080100m2·¼¶主缆有应力长结果分别列于表1和表2176 工程力学表1 水平张力H和y值比较Table 1 Comparison of horizontal component of cable tension and y-coordinate矢高f/m不考虑q变化60 70 80 90 100417807.1 358284.5 313663.7 278977.1 251244.1水平张力H/kN 考虑q变化417495.8 358054.5 313486.6 278836.3 251129.2文献[6] 417801.2 358282.3 313663.4 278978.8 251245.7抛物线法417271.2 357661.0 312953.4 278180.8 250362.7不考虑q变化15.8068 18.4351 21.0606 23.6829 26.3017x=228m处y值/m 考虑q变化15.8069 18.4352 21.0608 23.6831 26.3020文献[6] 15.8063 18.4349 21.0606 23.6834 26.3023抛物线法15.8218 18.4587 21.0957 23.7327 26.3696表2 索长值比较Table 2 Comparison of cable length矢高f/m有应力索长s/m不考虑q变化60 70 80 90 100898.7006 902.5123 906.8772 911.7824 917.2136考虑q变化898.7006 902.5123 906.8772 911.7822 917.2135精确无应力索长s0/m 不考虑q变化895.5447 899.7814 904.4620 909.6099 915.2328考虑q变化895.5470 899.7831 904.4633 909.6109 915.2335不考虑q变化895.5335 899.7731 904.4556 909.6047 915.2285 一阶近似无应力索长s0/m 考虑q变化895.5359 899.7748 904.4569 909.6057 915.2293文献[6] 895.5321 899.7708 904.4525 909.6005 915.2234抛物线法895.5324 899.7683 904.4451 909.5859 915.1984比较表1和表2的计算结果可见说明计算精度较高抛物线法与其它方法相比误差较大考虑和不考虑主缆弹性伸长对主缆线比重的影响水平张力相差稍大误差随垂度增加而减小主缆张力精度对于强度设计已足够但对采用新型索材的超大跨悬索桥建议按考虑主缆线比重变化的公式计算主缆参考文献中(3) 在一般跨度悬索桥的设计与施工控制分析对于超大跨悬索桥主缆有应力和无应力长在其设计施工中十分重要(2) 本文计算公式由主缆微元力学平衡关系推得求解容易算例结果与文献[6]非常吻合剪力墙多垂直杆单元模型的改进及应用189为接近限制单元模型的高宽比(3) 剪力墙的拉压滞变模型和剪切滞变模型并不多见给出了多垂直杆单元的受压极限变形算例分析表明计算值与试验结果吻合较好本文方法适用于高层建筑结构的弹塑性静力和动力分析[1] 李国强, 周向明, 丁翔. 钢筋混凝土剪力墙非线性动力分析模型[J]. 世界地震工程, 2000, 2: 13-18.Li Guoqiang, Zhou Xiangming, Ding Xiang. Models of reinforced concrete shear walls for nonlinear dynamic analysis [J]. WorldInformation on Earthquake Engineering, 2000, 2: 13-18. (in Chinese)[2] 孙景江, 江近仁. 高层建筑抗震墙非线性分析的扩展铁木辛哥分层梁单元[J]. 地震工程与工程振动, 2001, 21(2):78-83.Sun Jingjiang, Jiang Jinren. Extended layered Timoshenko beam element for nonlinear analysis of RC high-rise buildings with structural walls [J]. Earthquake Engineering And Engineering Vibration, 2001, 21(2): 78-83. (in Chinese)[3] 蒋欢军, 吕西林. 用一种墙体单元模型分析剪力墙结构[J]. 地震工程与工程振动, 1998, 18(3): 40-48.Jiang Huanjun, Lu Xilin. Analysis of shear wall structures using a type of wall element [J]. Earthquake Engineering And Engineering Vibration, 1998, 18(3): 40-48. (in Chinese)[4] 汪梦甫, 周锡元. 钢筋混凝土剪力墙多垂直杆非线性单元模型的改进及其应用[J]. 建筑结构学报, 2002, 23(1): 38-42, 57.Wang Mengfu, Zhou Xiyuan. The improved parallelmulti-component model for the nonlinear seismic response analysis of RC walls and its application [J]. Journal of Building Structures, 2002, 23(1): 38-42, 57. (in Chinese)[5] 汪梦甫, 周锡元. 钢筋混凝土框架-剪力墙结构非线性地震反应实用分析方法的研究[J]. 土木工程学报, 2002, 35(6):32-38.Wang Mengfu, Zhou Xiyuan. A practical method for nonlinear seismic responses of RC frame-wall structure [J]. China Civil Engineering Journal, 2002, 35(6): 32-38. (in Chinese)[6] 沈蒲生, 王海波. 剪力墙结构的非线性地震反应分析[J]. 土木工程学报, 2003, 36(5): 11-16.Shen Pusheng, Wang Haibo. Nonlinear seismic response to shear wall structures [J]. China Civil Engineering Journal, 2003, 36(5): 11-16. (in Chinese)[7] 江近仁, 孙景江, 丁世文. 轴向循环荷载下钢筋混凝土柱的试验研究[J]. 世界地震工程, 1998, 14(4): 12-16. Jiang Jinren, Sun Jingjiang, Ding Shiwen. Experimental study of RC columns subjected to axial cyclic loads [J]. World Information on Earthquake Engineering, 1998, 14(4): 12-16. (in Chinese)[8] 吕西林, 金国芳, 吴晓涵. 钢筋混凝土结构非线性有限元理论与应用[M]. 上海: 同济大学出版社, 1997. Lu Xilin, Jin Guofang, Wu Xiaohan. Theory and application of nonlinear finite element of reinforced concrete [M]. Shanghai: Tongji University Press, 1997. (in Chinese)[9] Oesterle R G. Web crushing of reinforced concretestructural walls [J]. ACI Structural Journal, Proceedings, 1984, 81(3): 231-241.[10] F J Vecchio. Towards cyclic load modeling of reinforcedconcrete [J]. ACI Structural Journal, Technical, 1999, 96(2): 193-202.(上接)[5] 肖汝诚, 贾丽君, 王小同. 确定大跨悬索桥主缆成桥线形的虚拟梁法[J]. 计算力学学报学报, 1999, 16(1): 108-113.Xiao Rucheng, Jia Lijun, Wang Xiaotong. Fictitious beam method for determination of main cable shape of long-span suspension bridge[J]. Chinese Journal of Computational Mechanics, 1999, 16(1): 108-113. (in Chinese)[6] 沈锐利. 悬索桥主缆系统设计及架设计算方法研究[J].土木工程学报, 1996, 29(2): 3-9.Shen Ruili. Calculation methods for design and erection of cables of suspension bridge[J]. Journal of Civil Engineering, 1996, 29(2): 3-9.(in Chines)[7] 唐茂林, 强士中, 沈锐利. 悬索桥成桥主缆线形计算的分段悬链线法[J]. 铁道学报, 2003, 25(1): 87-91.Tang Maolin, Qiang Shizhong, Shen Ruili. Segmental catenary method of calculating the cable curve ofsuspension bridge [J]. Journal of the China Railway Society, 2003, 25(1): 87-91. (in Chinese)[8] 肖汝诚. 确定大跨径桥梁结构合理设计状态的理论与方法研究[D]. 上海: 同济大学, 1996. Xiao Rucheng. Theoriesand methods for determinationof reasonable design state of long span bridges [D]. Shanghai: Tongji University, 1996. (in Chinese)[9] 罗喜恒. 复杂悬索桥施工过程精细化分析研究[D]. 上海: 同济大学, 2004. Luo Xiheng. Fine analysis of construction process ofcomplex suspension bridges [D]. Shanghai: Tongji University, 2004. (in Chinese)[10] 徐士良. FORTRAN常用算法程序集[M]. 北京: 清华大学出版社, 1992. 98-127.Xu Shiliang. A library of common FORTRAN routines [M]. Beijing: Tsinghua University Press, 1992. 98-127. (in Chinese)万方数据作者:作者单位:张志国,邹振祝,赵玉成,陈伟,ZHANG Zhi-guo,ZOU Zhen-zhu,ZHAO Yu-cheng,CHEN Wei张志国,ZHANG Zhi-guo(哈尔滨工业大学航天工程与力学系,黑龙江,哈尔滨,150001),邹振祝,ZOU Zhen-zhu(哈尔滨工业大学航天工程与力学系,黑龙江,哈尔滨,150001;石家庄铁道学院土木分院,河北,石家庄,050043),赵玉成,陈伟,ZHAO Yu-cheng,CHEN Wei(石家庄铁道学院土木分院,河北,石家庄,050043)工程力学ENGINEERING MECHANICS2005,22(3)1次刊名:英文刊名:年,卷(期):被引用次数:参考文献(10条)1.钱冬生.陈仁福大跨悬索桥的设计与施工19972.N J Gimsing Cable supported bridges-concept and design 19973.H M Irvine Cable structures 19814.史建三悬索桥大缆架设计算的索长分析法[期刊论文]-桥梁建设1993(04)5.肖汝诚.贾丽君.王小同确定大跨悬索桥主缆成桥线形的虚拟梁法[期刊论文]-计算力学学报1999(01)6.沈锐利悬索桥主缆系统设计及架设计算方法研究1996(02)7.唐茂林.强士中.沈锐利悬索桥成桥主缆线形计算的分段悬链线法[期刊论文]-铁道学报2003(01)8.肖汝诚确定大跨径桥梁结构合理设计状态的理论与方法研究[学位论文] 19969.罗喜恒复杂悬索桥施工过程精细化分析研究[学位论文] 200410.徐士良FORTRAN常用算法程序集1992引证文献(1条)1.赵文婷空间缆索悬索桥主缆线形的分析方法[期刊论文]-黑龙江交通科技2008(4)本文链接:/Periodical_gclx200503030.aspx。
北京三里屯SOHO项目开业
的人行天桥侧向振动问题得到了越来越多的关注,许多学者提出了自己的理论或经验公式。
如Bachmann 基于67个不同结构类型人行天桥的经验数据,提出人行天桥第一自振频率和跨度之间的关系,并建议人行天桥侧向振动加速度限值为0 1~0 2m s2,同时,为避免梁侧向共振,人行天桥侧向摇摆幅值还应小于2mm[16];Wheeler提出了竖向振动最大速度24mm s的舒适度标准[17];Leonhardt建议人行天桥最大侧向加速度应该为最大竖向加速度的1 5[18];文[19]认为悬索人行天桥侧向、扭转、竖向和径向四种振动模态中,侧向和扭转模态通常是组合出现的,且低频振动对其影响较大。
法国人行天桥设计指南在以上研究成果基础上认为人行天桥水平方向振动加速度低于0 1m s2时,共振概率为5%~10%,在0 1~0 15m s2时,人群行为基本保持随机状态;超过这一范围,共振概率会达到30% ~50%。
如果考虑人群之间发生冲撞、压缩,则这一概率会大于60%。
同时,振动加速度也会由0 1m s2突然增大到0 6m s2,人会感觉非常不舒适。
由此得出的结论是在考虑 人群锁定效应 工况下,人行天桥的水平振动加速度应低于0 1m s2。
4结论通过对13个国家(组织、地区)人行天桥舒适度标准的探讨及算例分析可以发现,各国标准均建立在简谐荷载共振模型基础上,单个人的重量也都为0 7kN。
虽然人行天桥自振频率的计算公式不同,但计算结果没有太大差异。
AISC标准给出的自振频率公式力学概念清晰,计算简单,与我国!高层民用建筑钢结构技术规程∀(JGJ99 98)第7章给出的式(7 3 8)基本相同,建议设计中采用AI SC标准。
人群的随机分布情况以及人行天桥计算模型的深化还有待进一步研究。
参考文献[1]叶正强,李爱群,丁幼亮.某大跨人行天桥的消能减振设计(一)[J].特种结构,2003,20(1).[2]吕佐超,韩合军,黄健等.北京银泰中心楼盖体系舒适度设计[J].建筑结构,2007,37(11):20 22.[3]城市人行天桥与人行地道技术规范(CJJ69 95)[S].[4]Floor Vibrations due to Human Activi ty[S].AISC Steel Design GuideSeries No.11,1997.[5]Mechanical vibration and s hock evaluation of human exposure to wholebody vi bration Part1:General Requi rements[S].ISO2631 11997. [6]Asses sment of vibrational behaviour of footbridges under pedestrianloading[S].The France Technical Depart ment for Transport,Roadsand Bridges Engineering and Road Safety,October2006.[7]Design Cri teria for Footbridges,Desi ng Manual for Roads and Bridges[S].BD29 04,2004.08.[8]Loads for Highway Bridges,Design M anual for R oads and Bri dges[S].BD37 01,2002.05.[9]Steel,concrete and composite bridges Part2.Specificati on for loads[S].BS5400:Part2:1978.[10]Bridge Manual Second Edi ti on2003(Includes amendments J une2004,September2004and July2005)[S].ISBN0 478 04132 2,Transit Ne w Zealand.[11]Eurocode1:Actions on structures Part2:Traffic loads on bri dges[S].Supersedes ENV1991 3:1995,September2003.[12]Fi nnis h National Anne x to EN1990 A2Basis of s tructural designAnnex A2:Application for bridges(Normative)[S].31December 2004.[13]The Code of Practice for the Structural Use of Steel[S].TheGovernment of the Hong Kong Special Admini strative Region,First publi shed:Augus t2005.[14]Footbridge vibrations due to pedes trian load[R].Danish guidelines andexamples by Fr d ric S bas tien Collette,2006.[15]BR AND M,ENG B.Dynamic Res pons e of Pedestrian Bridges forR andom Crowd Loading[R].2003.[16]BACHMA NN H,Lively footbridges a real challenge[C].Footbridge2002Conference,Paris,2002.[17]WHEELER J E.Prediction and control of pedes trian induced vibrationin footbridge[J].J.Struc t.Di v.ASCE1,108109(1982). [18]TILLY G P,CALLINGTON D W,Eyre R.Dynamic behavi or offootbridges[J].IABSE Surveys S 26(84),(1984).[19]HUANG M H,THAMBIR ATNA M D P,PERER A N J.D ynamicperformance of slender sus pensi on footbridges under eccentric wal king dynamic loads[J].J ournal of Sound and Vibration303(1 2):239 254, 2007.北京三里屯SOH O项目开业斑驳的光影,闪动的珠光,绚烂与迷幻撞激着现实与幻境,音乐响起,镁光灯汇聚,大幕开启,是真实在虚拟中迷失还是幻象变为现实,在电影的光影世界里,由SO HO 中国开发的三里屯SO HO终于揭开她神秘的面纱,向世人展现她妩媚的身姿,2008年7月19日开业。
机动车底盘动态检测流程及项目
机动车底盘动态检测流程及项目English response:The dynamic testing process for the chassis of motor vehicles involves several key steps and projects. These are essential for ensuring the safety, performance, and compliance of the vehicle with regulatory standards. Below are the main components of the dynamic testing process for motor vehicle chassis:1. Visual Inspection: The process begins with a visual inspection of the chassis to identify any visible damage, corrosion, or wear and tear. This step is crucial for identifying any potential issues that may affect the structural integrity of the vehicle.2. Measurement of Chassis Dimensions: Precise measurements of the chassis dimensions are taken to ensure that the vehicle meets the manufacturer's specifications. This involves measuring the wheelbase, track width, andother critical dimensions to verify that they fall within acceptable tolerances.3. Suspension and Steering System Testing: The suspension and steering systems are tested to assess their performance and functionality. This involves evaluating the responsiveness of the steering, the stability of the suspension, and the overall handling of the vehicle.4. Brake Testing: The braking system is thoroughly tested to ensure that it meets safety standards and is capable of bringing the vehicle to a stop effectively. This includes testing the brake force distribution, brake pedal feel, and overall braking performance.5. Dynamic Load Testing: The chassis is subjected to dynamic load testing to assess its structural strength and durability. This involves simulating real-world driving conditions and evaluating how the chassis responds to various loads and forces.6. Vibration Testing: Vibration testing is conducted toassess the chassis' ability to withstand vibrations and oscillations that occur during normal driving conditions. This helps identify any potential weaknesses or areas of concern that may affect the vehicle's performance and comfort.7. Compliance Testing: The vehicle is tested to ensure compliance with regulatory standards and safety requirements. This involves verifying that the chassis meets all relevant regulations and standards for structural integrity and safety.Overall, the dynamic testing process for motor vehicle chassis is a comprehensive evaluation of the vehicle's structural integrity, performance, and safety. By following these key steps and projects, manufacturers and regulatory authorities can ensure that motor vehicles are safe, reliable, and compliant with industry standards.中文回答:机动车底盘动态检测流程涉及几个关键步骤和项目。
210974880_粘滞阻尼器对加劲梁带外伸跨悬索桥的减震分析
0引言悬索桥是一种大跨度柔性结构,对风、地震等动力作用较为敏感,在地震作用下桥塔和加劲梁易产生较大的内力位移响应,强大的地震作用可能造成结构损伤和破坏,在塔、梁间设置粘滞阻尼器是一种有效且常用的减小加劲梁纵向地震位移的措施[1,2],而粘滞阻尼器的减震效果取决于阻尼器的布置位置和阻尼器的阻尼系数和速度指数。
目前,国内较多学者基于粘滞阻尼器对大跨度悬索桥的减震展开了一系列的研究。
权新蕊[3]等以某近活动断裂带的悬索桥为研究对象,进行了粘滞阻尼器减震优化设计,优化后的阻尼器可有效限制加劲梁在地震作用下的纵向位移。
江辉[4]等以某“V ”型峡谷大跨度悬索桥为背景进行了该桥的抗震性能和减震研究,研究表明在塔梁连接处设置粘滞阻尼器可使主塔弯矩、剪力及梁端位移降低14%~70%不等。
卢长炯[5]等通过时程分析法计算了某公路悬索桥重点部位的地震位移响应,分析了阻尼器主要技术参数对该桥地震位移响应的影响规律。
郭志明[6]以南京仙新路悬索桥为背景,研究纵向抗震体系,认为粘滞阻尼器减震效果远比柔性中央扣好,粘滞阻尼器的参数应综合考虑静力和地震响应优化确定。
石瑶[7]研究了设置粘滞阻尼器悬索桥的地震响应,结果表明阻尼器可明显改善桥塔的受力情况。
既有文献很少有针对加劲梁带外伸跨悬索桥纵向减震的研究,鉴于此,本文以某加劲梁带外伸跨的大跨度悬索桥为研究对象,进行动力计算,分析该类型悬索桥粘滞阻尼器的合理布置位置以及阻尼器参数对地震内力位移响应的影响规律。
1工程背景某加劲梁带外伸跨的钢桁梁悬索桥,主缆分跨布置为:260+1060+260m ,主缆采用空间缆形式,塔上主缆横向间距40m ,跨中横向间距30m ,成桥状态矢跨比为1/9。
加劲梁为单跨悬吊钢桁梁,分跨布置为:130+1060+130m 。
加劲梁采用带竖杆的华伦式钢桁架,节间长度10m ,桁高12m ,桁宽30m 。
桥塔采用普通钢筋混凝土门形塔,两岸塔高259m ,设上下两道横梁,塔柱采用单箱单室箱形截面,截面尺寸由塔顶9m (顺桥向)×9m (横桥向),线性变化为塔底15m (顺桥向)×11m (横桥向)。
自锚式独塔悬索桥竖向弯曲振动基频估算公式
自锚式独塔悬索桥竖向弯曲振动基频估算公式郭俊;刘胜红;高嵩;蔡林真【摘要】为方便计算自锚式独塔悬索桥的竖向自振频率,以塔梁支承体系的独塔自锚式悬索桥为研究对象,采用能量法,推导了该体系的竖向弯曲振动频率公式,最后对此公式可行性进行了算例验证.研究结果表明:文中所推导解析解的竖弯基频计算值与文献解之间的误差能满足初步设计阶段要求;该公式可用于该体系在初步概念设计中选择合理的结构计算参数.【期刊名称】《重庆交通大学学报(自然科学版)》【年(卷),期】2019(038)005【总页数】6页(P27-32)【关键词】桥梁工程;自锚式独塔悬索桥;竖弯频率;能量法;估算公式【作者】郭俊;刘胜红;高嵩;蔡林真【作者单位】云南云路工程检测有限公司,云南昆明655600;云南云路工程检测有限公司,云南昆明655600;云南云路工程检测有限公司,云南昆明655600;云南云路工程检测有限公司,云南昆明655600【正文语种】中文【中图分类】U441.3独塔自锚式悬索桥具有造型优美、观赏效果极佳等特点,是一种在城市市区或风景区等对景观要求较高地方具有竞争力的桥型。
独塔自锚式悬索桥固有振动特性研究是分析该体系动力特性的基础[1-6]。
由于自锚式悬索桥是将主缆锚固在加劲梁上,此时加劲梁将承受较大轴向压力,故将导致其与地锚式悬索桥动力特性存在着较大差异[7-8]。
王志诚[9]在考虑主塔刚度影响与否下,分别推导了带有外伸梁的双塔自锚式悬索桥竖向振动基频估算实用公式;张超等[10]采用Rayleigh法,在计入主塔刚度影响下,以三塔自锚式悬索桥为研究对象,推导了该体系竖向弯曲振动基频计算式;文献[11]所给出的振动基频估算式仅只针对地锚式悬索桥,而并未给出自锚式独塔悬索桥振动基频估算公式;王玉田等[12]以青岛海湾桥为研究对象,采用有限元分析对其开展了动力特性研究。
上述研究成果表明:学界对对称自锚式独塔悬索桥动力特性研究较少[13-14]。
case study of(参考版)
Case study of bridge with viscous dampers1 Protecting function of viscous dampers for expansion jointsin long span bridgesViscous dampers are usually selected to be equipped at the bridge ends to restrict their displacements. Under this condition, viscous dampers and expansion joints are usually parallel in bridge structure. Whether the viscous dampers have the protecting function or not for expansion joint under the impact force caused by earthquake, wind and vehicle etc is focused in this case study.Xihoumen bridge is a sea-crossing suspension bridge (see Fig.1). The span length is 578m+1650m+485m. The main beams of the north side span and mid span are designed as continuous stiffening girder. Suspension structure with lateral wind-resistance bearings is designed between north side span and north bridge tower, and no lower beam is equipped in the north bridge tower. In the south bridge tower, lower beam is fixed and connected with huge force-reaction wall. So, the viscous dampers are installed between the stiffening girder end and the force reaction wall. Dynamic time-history analysis is done in El-Centro earthquake with probability 3% in 100 year return period. Results of protecting effect of viscous dampers for expansion joints in long span bridges are given in table 1&2 and shown in Fig.2&3. It can be found easily that the displacement and velocity responses of the Xihoumen super suspension bridge is reduced greatly with the installation of viscous dampers between the stiffening girder end and the force reaction wall. And also the expansion joints of the suspension bridge can be protected reliably.Fig.1 The layout of Xihoumen suspension bridgeTable 2 Relative velocity aFig.2 Comparison of relative displacements of north beam endFig.3 Comparison of relative velocities of north beam end2 Case study on lateral response reduction of long-spanrailway cable-stayed bridge with viscous dampersThe long-span railway cable-stayed bridge is a semi-floating system with span length of 81m+135m+432m+135m+81m (see Fig.4). The main bridge beam is a steel truss with width of 18m and height of 14m. The length of each truss section is 13.5m. High-strength steel wires are adopted and designed as materials of the 56 pairs of stable cables. The cable spacing distance is 2.5m-4.0m on the main bridge tower and 13.5m on the main bridge beam. The bridge surface is integral orthotropic steel plates. Dynamic responses are conducted by Midas software in three earthquakes with probability 2-3% in 50 year return period. The peak accelerations of the thee earthquakes are all the same of 0.21g. The specific installation places of the viscous damper are shown in Fig.5. Computational results of dynamic transverse relative displacement responses between bridge pier and beam are shown in Fig.6 and the hysteresis curves of viscous dampers between damping force and displacement are shown in Fig.7.It can be found that the earthquake-reduction system is better than other systems by setting up viscous dampers between auxiliary pier, transition pier and bridge beam, for lateral seismic response of main tower, auxiliary pier and transition pier can be significantly reduced. Future more, seismic performance of pile foundations for auxiliary and transition pier can be improved.Fig.4 The long-span railway cable-stayed bridge model (1# is transition bridge pier, 2# is auxiliary bridge pier, 3# is bridge main tower, 4# is bridge main tower, 5# istransition bridge pier, and 6# is bridge abutment)Fig.5 Installation places of viscous dampersFig. 6 Transverse relative displacement between 1#pier and bridge beamFig.7 Hysteresis curves of viscous damper at 2# bridge pier.3 Case study on seismic performance improvement forsouthern branch main bridge of a sea-crossing bridge with viscous dampersThe southern branch main bridge of the sea-crossing bridge in this case study is a semi-floating system with span length of 130m+290m+130m (see Fig.8). The cross-section of the main beam of the southern branch bridge is single-box concrete section with three holes. The height of the cross section is 3.5m and width is 32.2m. The height of the main bridge tower is 132.6m above the bridge pile.This bridge lies in the earthquake-prone areas and the peak acceleration is very big in this area. In this case study, the peak acceleration is 0.311g. In order to improve the dynamic responses of the bridge in design earthquake excitations, viscous dampers are selected and installed under the main bridge beam, namely between the main longitudinal bridge beam and the bridge pier (see Fig.9). Parameter analysis of viscous dampers, such as damping coefficients and damping index, is conducted so as to obtain the optimal damper parameters. The parameters studied in this case study are listed in Table 3.The influence of damper parameters, damping coefficients and damping index, to the energy dissipation ratios of the bridge are shown in Fig.10 & 11,respectively. According to the parameter analysis based on the figures of Fig.10 & 11, the optimal damping parameters can then be easily obtained and given in Table 4.As a result, two vibration control plans are designed. The first one is that 4 viscous dampers are installed between the main bridge beam and the bridge pier of the main tower. And the second is that 4 viscous dampers are installed between the main bridge beam and the bridge pier of the main tower, and 4 dampers are installed between the main bridge beam and the transition bridge pier. However, the total damping coefficients of the two plans are the same for comparison purpose. Comparison of energy dissipation ratio of the bridge with the two control plans are shown in Fig.12. The symbol meanings listed in the Fig. 12 are given in Table 5. Obviously, the analysis indicates that both relative displacement of key points and seismic response of key components could be obviously reduced with reasonably choosing the parameters and locations of dampers.Fg.8 The southern branch main bridge modelFg.9 Installation of the viscous damper under the main bridge beam(a) Influence of C to displacement of beam end (b) Influence of C to displacement of top tower(c) Influence of C to moment of tower bottom (d) Influence of C to moment of top pile Fig.10 Influence of damping coefficients C to the energy dissipation ratio of different parameterresponses(a) Influence of α to displacement of beam end (b) Influence of αto displacement of top tower(c) Influence of αto moment of tower bottom (d) Influence of αto moment of top pileFig. 11 Influence of damping index αto the energy dissipation ratio of different parameterresponsesFig. 12 Comparison of energy dissipation ratio of the bridge with the two control plans4 Case study on performance improvement of stay cable ofJianshao bridge using viscous dampersIn this case study, Jianshao cable-stayed bridge with 69,500m length and 6 main tower is introduced (see Fig.13). The span length is 70m+200m+5×428m+200m +70m. The cables are made up of parallel high-strength steel wires with diameter size of 7mm. Totally, there are 576 stay cables and 432 of these stay cables are installed viscous so as to improve the vibration performance, see Fig.14. The parameters of the viscous dampers are given in Table 6.Site measurement values of the logarithmic decrement ratio of the No. Z5W-B10 cable with and without viscous dampers are given in Table 7. The free decay curves of the No. Z5W-B10 cable using also the site measurement method are shown in Fig.15. And the hysteresis curves of the viscous dampers are shown in Fig.16. The results show that viscous dampers can be able to curb the vibration of stay cables, which can be the permanent vibration control measure for stay cables. And the results of the testing demonstrate that the viscous dampers show stable performance, all the performance index can meet the design requirements. The measured logarithmic decrement is above 6%, basically in compliance with the changing rule of the theoretical values, proving that the viscous dampers have sound vibration damping effect.Fig.13 Jianshao cable-stayed bridge(a) Before installation of viscous dampers (b) After installation of viscous dampersFig.14 Site installation of viscous dampersTable 7 Site measurement values of the logarithmic decrement ratio of the No.(a) Original curves(b) Filtering curve of the 1st order(c) Filtering curve of the 2nd order(d) Filtering curve of the 3rd orderFig.15 Free decay curves of the No. Z5W-B10 cableFig.16 Hysteresis curves of the viscous dampers used in the stay cable of Jiaoshao bridge。
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Dynamic Response of Suspension Bridge to Typhoon and Trains. II: Numerical Results
W. W. Guo1; Y. L. Xu, M.ASCE2; H. Xia3; W. S. Zhang4; and K. M. Shum5
1 Lecturer, School of Civil Engineering, Beijing Jiaotong Univ., Beijing, China. 2 Chair Professor, Dept. of Civil and Structural Engineering, The Hong Kong Polytechnic Univ., Kowloon, Hong Kong, China. 3 Professor, School of Civil Engineering, Beijing Jiaotong Univ., Beijing, China. 4 Professor, Dept. of Engineering Mechanics, Dalian Univ. of Technology, Dalian, China. 5 Research Associate, Dept. of Civil and Structural Engineering, The Hong Kong Polytechnic Univ., Kowloon, Hong Kong, China. Note. Associate Editor: Abhinav Gupta. Discussion open until June 1, 2007. Separate discussions must be submitted for individual papers. To extend the closing date by one month, a written request must be filed with the ASCE Managing Editor. The manuscript for this paper was submitted for review and possible publication on August 9, 2005; approved on May 10, 2006. This paper is part of the Journal of Structural Engineering, Vol. 133, No. 1, January 1, 2007. ©ASCE, ISSN 0733-9445/2007/1-12– 21/$25.00.
Introduction
Dynamic interaction between railway bridges and trains has been an important subject of research since the early 20th Century. During the past two decades, a number of sophisticated models have been developed to investigate the dynamic interaction between bridges and trains. Diana and Cheli ͑1989͒ presented a finite element based numerical model in conjunction with a direct integration method to investigate the dynamic interaction between long suspension bridges and trains. Yang and Yau ͑1997͒ developed a special vehicle-bridge interaction element for the dynamic analysis of coupled train and bridge systems. Xia et al. ͑2000͒ also investigated the dynamic interaction between long suspension bridges and trains but used four-axle vehicle modelson technique. Au et al. ͑2001͒ carried out an
impact study of a cable-stayed bridge under railway traffic using various vehicle models from 2 to 10 degree-of-freedom systems. In the simulation of vehicle-bridge dynamic interactions, track irregularities should be taken into account. Xia et al. ͑2000͒ used the measured track vertical, lateral, and torsional irregularities from one of the main railways in China in their work. Zhang et al. ͑2001͒, however, simulated track irregularities based on the power spectral density functions. When long-span cablesupported bridges carrying railways are located in wind prone regions, the dynamic interaction between wind, trains, and bridges should be considered. Xu et al. ͑2003͒ presented a framework for predicting the dynamic response of a long suspension bridge to high winds and running trains based on the vehiclebridge dynamic interaction work of Xia et al. ͑2000͒. The rationality and feasibility of the proposed framework and the accuracy of dynamic responses of the system predicted from the framework, however, have not been verified yet. The field measurement data of the Tsing Ma suspension bridge during Typhoon York, recorded by the Wind and Structural Health Monitoring System ͑WASHMS͒, have been analyzed and the four particular cases have been presented in a companion paper. The four cases identified include ͑1͒ the bridge without any vehicles; ͑2͒ the bridge with one train; ͑3͒ the bridge with two trains running in opposite directions; and ͑4͒ the bridge with three running trains. The mean wind speed in each case is almost perpendicular to the bridge alignment to facilitate comparison with the numerical results. The field measurement results are now used to verify, to some extent, the finite element based framework developed by the writers in the time domain for predicting a dynamic response of coupled train and bridge systems in cross winds. A threedimensional finite element model is used to model the Tsing Ma suspension bridge. Wind forces acting on the bridge are generated