Modal Analysis of Construction Hoist Based on ANSYS
土木工程外文翻译---高层结构与钢结构
第五部分英文论文翻译Talling building and Steel constructionAlthough there have been many advancements in building construction technology in general. Spectacular archievements have been made in the design and construction of ultrahigh-rise buildings.The early development of high-rise buildings began with structural steel framing.Reinforced concrete and stressed-skin tube systems have since been economically and competitively used in a number of structures for both residential and commercial purposes.The high-rise buildings ranging from 50 to 110 stories that are being built all over the United States are the result of innovations and development of new structual systems.Greater height entails increased column and beam sizes to make buildings more rigid so that under wind load they will not sway beyond an acceptable limit.Excessive lateral sway may cause serious recurring damage to partitions,ceilings.and other architectural details. In addition,excessive sway may cause discomfort to the occupants of the building because their perception of such motion.Structural systems of reinforced concrete,as well as steel,take full advantage of inherent potential stiffness of the total building and therefore require additional stiffening to limit the sway.In a steel structure,forexample,the economy can be defined in terms of the total average quantity of steel per square foot of floor area of the building.Curve A in Fig .1 represents the average unit weight of a conventional frame with increasing numbers of stories. Curve B represents the average steel weight if the frame is protected from all lateral loads. The gap between the upper boundary and the lower boundary represents the premium for height for the traditional column-and-beam frame.Structural engineers have developed structural systems with a view to eliminating this premium.Systems in steel. Tall buildings in steel developed as a result of several types of structural innovations. The innovations have been applied to the construction of both office and apartment buildings.Frame with rigid belt trusses. In order to tie the exterior columns of a frame structure to the interior vertical trusses,a system of rigid belt trusses at mid-height and at the top of the building may be used. A good example of this system is the First Wisconsin Bank Building(1974) in Milwaukee.Framed tube. The maximum efficiency of the total structure of a tall building, for both strength and stiffness,to resist wind load can be achieved only if all column element can be connected to each other in such a way that the entire building acts as a hollow tube or rigid box in projecting out of the ground. This particular structural system was probably used for the first time in the 43-story reinforced concreteDeWitt Chestnut Apartment Building in Chicago. The most significant use of this system is in the twin structural steel towers of the 110-story World Trade Center building in New YorkColumn-diagonal truss tube. The exterior columns of a building can be spaced reasonably far apart and yet be made to work together as a tube by connecting them with diagonal members interesting at the centre line of the columns and beams. This simple yet extremely efficient system was used for the first time on the John Hancock Centre in Chicago, using as much steel as is normally needed for a traditional 40-story building.Bundled tube. With the continuing need for larger and taller buildings, the framed tube or the column-diagonal truss tube may be used in a bundled form to create larger tube envelopes while maintaining high efficiency. The 110-story Sears Roebuck Headquarters Building in Chicago has nine tube, bundled at the base of the building in three rows. Some of these individual tubes terminate at different heights of the building, demonstrating the unlimited architectural possibilities of this latest structural concept. The Sears tower, at a height of 1450 ft(442m), is the world’s tallest building.Stressed-skin tube system. The tube structural system was developed for improving the resistance to lateral forces (wind and earthquake) and the control of drift (lateral building movement ) in high-rise building. The stressed-skin tube takes the tube system a step further. The development of the stressed-skin tube utilizes the fa?ade of the building as a structural element which acts with the framed tube, thus providing an efficient way of resisting lateral loads in high-rise buildings, and resulting in cost-effective column-free interior space with a high ratio of net to gross floor area.Because of the contribution of the stressed-skin fa?ade, the framed members of the tube require less mass, and are thus lighter and less expensive. All the typical columns and spandrel beams are standard rolled shapes,minimizing the use and cost of special built-up members. The depth requirement for the perimeter spandrel beams is also reduced, and the need for upset beams above floors, which would encroach on valuable space, is minimized. The structural system has been used on the 54-story One Mellon Bank Center in Pittburgh.Systems in concrete.While tall buildings constructed of steel had an early start, development of tall buildings of reinforced concrete progressed at a fast enough rate to provide a competitive chanllenge to structural steel systems for both office and apartment buildings.Framed tube. As discussed above, the first framed tube concept for tall buildings was used for the 43-story DeWitt Chestnut Apartment Building. In this building ,exterior columns were spaced at 5.5ft (1.68m) centers, and interior columns were used as needed to support the 8-in . -thick (20-m) flat-plate concrete slabs.Tube in tube. Another system in reinforced concrete for office buildings combines the traditional shear wall construction with an exterior framed tube. The system consists of an outer framed tube of very closely spaced columns and aninterior rigid shear wall tube enclosing the central service area. The system (Fig .2), known as the tube-in-tube system , made it possible to design the world’s present tallest (714ft or 218m)lightweight concrete building ( the 52-story One Shell Plaza Building in Houston) for the unit price of a traditional shear wall structure of only 35 stories.Systems combining both concrete and steel have also been developed, an examle of which is the composite system developed by skidmore, Owings &Merril in which an exterior closely spaced framed tube in concrete envelops an interior steel framing, thereby combining the advantages of both reinforced concrete and structural steel systems. The 52-story One Shell Square Building in New Orleans is based on this system.Steel construction refers to a broad range of building construction in which steel plays the leading role. Most steel construction consists of large-scale buildings or engineering works, with the steel generally in the form of beams, girders, bars, plates, and other members shaped through the hot-rolled process. Despite the increased use of other materials, steel construction remained a major outlet for the steel industries of the U.S, U.K, U.S.S.R, Japan, West German, France, and other steel producers in the 1970s.Early history. The history of steel construction begins paradoxically several decades before the introduction of the Bessemer and the Siemens-Martin (openj-hearth) processes made it possible to produce steel in quantities sufficient for structure use. Many of problems of steel construction were studied earlier in connection with iron construction, which began with the Coalbrookdale Bridge, built in cast iron over the Severn River in England in 1777. This and subsequent iron bridge work, in addition to the construction of steam boilers and iron ship hulls , spurred the development of techniques for fabricating, designing, and jioning. The advantages of iron over masonry lay in the much smaller amounts of material required. The truss form, based on the resistance of the triangle to deformation, long used in timber, was translated effectively into iron, with cast iron being used for compression members-i.e, those bearing the weight of direct loading-and wrought iron being used for tension members-i.e, those bearing the pull of suspended loading.The technique for passing iron, heated to the plastic state, between rolls to form flat and rounded bars, was developed as early as 1800;by 1819 angle irons were rolled; and in 1849 the first I beams, 17.7 feet (5.4m) long , were fabricated as roof girders for a Paris railroad station.Two years later Joseph Paxton of England built the Crystal Palace for the London Exposition of 1851. He is said to have conceived the idea of cage construction-using relatively slender iron beams as a skeleton for the glass walls of a large, open structure. Resistance to wind forces in the Crystal palace was provided by diagonal iron rods. Two feature are particularly important in the history of metal construction; first, the use of latticed girder, which are small trusses, a form first developed in timber bridges and other structures and translated into metal by Paxton ; and second, the joining of wrought-iron tension members and cast-ironcompression members by means of rivets inserted while hot.In 1853 the first metal floor beams were rolled for the Cooper Union Building in New York. In the light of the principal market demand for iron beams at the time, it is not surprising that the Cooper Union beams closely resembled railroad rails.The development of the Bessemer and Siemens-Martin processes in the 1850s and 1860s suddenly open the way to the use of steel for structural purpose. Stronger than iron in both tension and compression ,the newly available metal was seized on by imaginative engineers, notably by those involved in building the great number of heavy railroad bridges then in demand in Britain, Europe, and the U.S.A notable example was the Eads Bridge, also known as the St. Louis Bridge, in St. Louis (1867-1874), in which tubular steel ribs were used to form arches with a span of more than 500ft (152.5m). In Britain, the Firth of Forth cantilever bridge (1883-90) employed tubular struts, some 12 ft (3.66m) in diameter and 350 ft (107m) long. Such bridges and other structures were important in leading to the development and enforcement of standards and codification of permissible design stresses. The lack of adequate theoretical knowledge, and even of an adequate basis for theoretical studies, limited the value of stress analysis during the early years of the 20th century,asiccasionallyfailures,such as that of a cantilever bridge in Quebec in 1907,revealed.But failures were rare in the metal-skeleton office buildings;the simplicity of their design proved highly practical even in the absence of sophisticated analysis techniques. Throughout the first third of the century, ordinary carbon steel, without any special alloy strengthening or hardening, was universally used.The possibilities inherent in metal construction for high-rise building was demonstrated to the world by the Paris Exposition of 1889.for which Alexandre-Gustave Eiffel, a leading French bridge engineer, erected an openwork metal tower 300m (984 ft) high. Not only was the height-more than double that of the Great Pyramid-remarkable, but the speed of erection and low cost were even more so, a small crew completed the work in a few months.The first skyscrapers. Meantime, in the United States another important development was taking place. In 1884-85 Maj. William Le Baron Jenney, a Chicago engineer , had designed the Home Insurance Building, ten stories high, with a metal skeleton. Jenney’s beams were of Bessemer steel, though his columns were cast iron. Cast iron lintels supporting masonry over window openings were, in turn, supported on the cast iron columns. Soild masonry court and party walls provided lateral support against wind loading. Within a decade the same type of construction had been used in more than 30 office buildings in Chicago and New York. Steel played a larger and larger role in these , with riveted connections for beams and columns, sometimes strengthened for wind bracing by overlaying gusset plates at the junction of vertical and horizontal members. Light masonry curtain walls, supported at each floor level, replaced the old heavy masonry curtain walls, supported at each floor level , replaced the old heavy masonry.Though the new construction form was to remain centred almost entirely in America for several decade, its impact on the steel industry was worldwide. By thelast years of the 19th century, the basic structural shapes-I beams up to 20 in. ( 0.508m) in depth and Z and T shapes of lesser proportions were readily available, to combine with plates of several widths and thicknesses to make efficient members of any required size and strength. In 1885 the heaviest structural shape produced through hot-rolling weighed less than 100 pounds (45 kilograms) per foot; decade by decade this figure rose until in the 1960s it exceeded 700 pounds (320 kilograms) per foot.Coincident with the introduction of structural steel came the introduction of the Otis electric elevator in 1889. The demonstration of a safe passenger elevator, together with that of a safe and economical steel construction method, sent building heights soaring. In New York the 286-ft (87.2-m) Flatiron Building of 1902 was surpassed in 1904 by the 375-ft (115-m) Times Building ( renamed the Allied Chemical Building) , the 468-ft (143-m) City Investing Company Building in Wall Street, the 612-ft (187-m) Singer Building (1908), the 700-ft (214-m) Metropolitan Tower (1909) and, in 1913, the 780-ft (232-m) Woolworth Building.The rapid increase in height and the height-to-width ratio brought problems. To limit street congestion, building setback design was prescribed. On the technical side, the problem of lateral support was studied. A diagonal bracing system, such as that used in the Eiffel Tower, was not architecturally desirable in offices relying on sunlight for illumination. The answer was found in greater reliance on the bending resistance of certain individual beams and columns strategically designed into the skeletn frame, together with a high degree of rigidity sought at the junction of the beams and columns. With today’s modern interior lighting systems, however, diagonal bracing against wind loads has returned; one notable example is the John Hancock Center in Chicago, where the external X-braces form a dramatic part of the structure’s fa?ade.World War I brought an interruption to the boom in what had come to be called skyscrapers (the origin of the word is uncertain), but in the 1920s New York saw a resumption of the height race, culminating in the Empire State Building in the 1931. The Empire State’s 102 stories (1,250ft. [381m]) were to keep it established as the hightest building in the world for the next 40 years. Its speed of the erection demonstrated how thoroughly the new construction technique had been mastered. A depot across the bay at Bayonne, N.J., supplied the girders by lighter and truck on a schedule operated with millitary precision; nine derricks powerde by electric hoists lifted the girders to position; an industrial-railway setup moved steel and other material on each floor. Initial connections were made by bolting , closely followed by riveting, followed by masonry and finishing. The entire job was completed in one year and 45 days.The worldwide depression of the 1930s and World War II provided another interruption to steel construction development, but at the same time the introduction of welding to replace riveting provided an important advance.Joining of steel parts by metal are welding had been successfully achieved by the end of the 19th century and was used in emergency ship repairs during World War I, but its application to construction was limited until after World War II.Another advance in the same area had been the introduction of high-strength bolts toreplace rivets in field connections.Since the close of World War II, research in Europe, the U.S., and Japan has greatly extended knowledge of the behavior of different types of structural steelunder varying stresses, including those exceeding the yield point, making possiblemore refined and systematic analysis. This in turn has led to the adoption of moreliberal design codes in most countries, more imaginative design made possible byso-called plastic design ?The introduction of the computer by short-cutting tediouspaperwork, made further advances and savings possible.高层结构与钢结构近年来，尽管一般的建筑结构设计取得了很大的进步，但是取得显著成绩的还要属超高层建筑结构设计。
模态分析(modal)
如果结构或者机器组件中存在阻尼，系统就变成阻尼模态分析，对于阻尼模态分析，固有频率和振型变得更加复杂。
For a rotating structure or machine component, the gyroscopic effects resulting from rotational velocities are introduced into the modal system. These effects in turn change the system’s damping. Such effects are commonly encountered in rotordynamic analysis. The changes in Eigen characteristics at different rotational velocity can be studied with the aid ofCampbell Diagram Chart Results.
Stiffness may be specified using isotropic and orthotropic elastic material models，Mass may derive from material density
硬度可以由材料的其他的材料数据定义，质量可以由材料的密度继承。
EXPERIMENTAL AND NUMERICAL MODAL ANALYSIS OF A CONCRETE
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EXPERIMENTAL AND NUMERICAL MODAL ANALYSIS OF A CONCRETE HIGH SPEED TRAIN RAILWAY BRIDGE
基于ANSYS对大型钢桁桥的模态分析
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表 1
阶次 AN SY S M idas
AN SY S 和 M idas 4阶 5阶 6阶 7阶 8阶
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所谓的模态分析就是确定结构系统 的振动特性, 得到结构的固有频率和 振型, 它们 是结构 承受 动力荷 载中的重要参数, 同时也 是结构其 它各类 型动 力学分 析的基础
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高层钢筋混凝土结构 abaqus参数化建模方法优秀毕业论文 可复制黏贴
Mechanical_Rotordynamics_14.5_L2_Modal
– Shaft end boundary conditions
• Case 1 – Very stiff bearings (consider pinned -pinned) • Case 2 – Soft bearings with stiffness 5 *10^6 N/m
Also called simple ‘flexible rotors’
•
Jeffcott Rotor 2
– – – Rotor mounted on very flexible bearings resulting in ‘bearing modes’ The rotor shaft is much stiffer compared to bearing and foundation support Also called simple ‘rigid rotors’
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Release 14.5
… Non-rotating Jeffcott Rotor
• Case 1: Considering very stiff bearing support (or simply supported shaft ends):
Moment of area
Recommendation: Because a structure’s vibration characteristics determine how it responds to any type of dynamic load, it is generally recommended to perform a modal analysis first before trying any other dynamic analysis.
fortify building analysis model
fortify building analysis modelTitle: A Comprehensive Analysis of the Fortify Building Analysis ModelIntroduction:The Fortify Building Analysis Model is a robust tool used in the construction industry to assess the structural integrity of a building. This model plays a crucial role in ensuring the safety and durability of structures, especially in areas prone to natural disasters such as earthquakes, hurricanes, or floods. In this article, we will delve into the various steps involved in the Fortify Building Analysis Model, highlighting its significance and impact on the construction industry.1. Understanding the Purpose:The first step in utilizing the Fortify Building Analysis Model involves understanding its purpose. Essentially, this model aims to evaluate the vulnerability of a building to various forces and loads, analyzing critical structural elements and identifying any potential weaknesses. By doing so, architects and engineers can take necessary measures to fortify the structure, ensuring it meets the required safety standards.2. Initial Assessment:Once the purpose is understood, an initial assessment of the building's structural elements, materials, and overall design is conducted. This assessment acts as a starting point for the analysis and would typically involve a careful examination of architectural drawings, blueprints, and any available data on the building's construction.3. Data Collection:The next step is to collect relevant data to feed into the Fortify Building Analysis Model. This may involve site visits, inspections, and the use of cutting-edge technology such as laser scanning or drones to obtain accurate measurements and assess the existing condition of the building. Additional data, such as geological and climatic information, is also collected to better understand external forces that could impact the structure's integrity.4. Modeling and Simulation:With the necessary data in hand, the Fortify Building Analysis Model utilizes advanced software platforms to create a virtual model of the building. This digital representation includes allstructural components such as beams, columns, walls, and foundations. The model simulates various scenarios, applying forces like wind, seismic activity, or extreme weather events to evaluate how the building would respond under such conditions.5. Analysis and Identifying Weaknesses:The simulated scenarios from the previous step help identify potential weaknesses in the building's design or materials. The analysis highlights critical areas that may require structural reinforcement or modification to enhance the building's overall stability and resistance to external forces. This step often involves intricate calculations and complex algorithms to determine the safety margin in each structural element.6. Recommended Fortification Measures:Based on the analysis, a comprehensive report is generated, outlining recommended fortification measures. These recommendations may include strengthening specific structural components, modifying the building's layout, reinforcing vulnerable areas, or suggesting the use of advanced materials for improved resilience. The report provides actionable guidelines for architects, engineers, and construction professionals to implementthe necessary changes.7. Testing and Validation:Before implementing the suggested fortification measures, physical testing and validation are crucial to ensure the proposed modifications will indeed strengthen the building. This phase might involve conducting small-scale tests, utilizing laboratory facilities, or employing computer simulations to validate the effectiveness of the recommended upgrades.8. Implementation and Monitoring:Once the fortification measures are approved, the implementation phase begins. Construction crews, under the guidance of structural engineers, carry out the necessary modifications following the detailed recommendations from the analysis report. Throughout the construction process, ongoing monitoring is vital to guarantee that the implemented changes align with the initial objectives and meet the desired safety standards.Conclusion:The Fortify Building Analysis Model is an essential tool for evaluating and improving the structural integrity of buildings. Byfollowing the aforementioned steps, architects, engineers, and construction professionals can ensure that structures are fortified to withstand potential hazards. This model plays a significant role in ensuring the safety and longevity of buildings, ultimately contributing to the overall resilience of communities against natural disasters and environmental challenges.。
装配式建筑工程师课程
装配式建筑工程师课程英文回答：As a modular construction engineer, I have found the course on modular construction engineering to be extremely valuable in enhancing my skills and knowledge in this field. The course covers a wide range of topics, including the design and fabrication of modular components, the assembly process, and the quality control measures to ensure the structural integrity of the final product.One of the key aspects that the course focuses on isthe design of modular components. This involves understanding the specific requirements of the project and translating them into modular units that can be easily manufactured and assembled on-site. The course provides in-depth knowledge on various design considerations such as material selection, structural analysis, and building code compliance. It also introduces advanced design techniques such as parametric modeling and digital fabrication, whichcan greatly improve the efficiency and accuracy of the design process.Another important aspect covered in the course is the assembly process of modular buildings. This includes understanding the different types of connections and fastening systems used in modular construction, as well as the sequencing and coordination of the assembly process. The course provides hands-on training on the proper techniques for assembling modular components, ensuring that they fit together seamlessly and securely. It also covers topics such as transportation logistics and on-site installation, which are crucial for a successful modular construction project.In addition to the technical aspects, the course also emphasizes the importance of quality control in modular construction. This includes conducting thorough inspections and tests at various stages of the construction process to ensure that the modular components meet the required standards. The course provides guidance on developing quality control plans and implementing quality assuranceprocedures to minimize the risk of defects and ensure the long-term durability of the modular building.Overall, the modular construction engineering course has provided me with a comprehensive understanding of the principles and practices of modular construction. It has equipped me with the necessary skills and knowledge to confidently design and construct modular buildings that meet the highest standards of quality and efficiency.中文回答：作为一名装配式建筑工程师，我发现装配式建筑工程师课程对于提升我的技能和知识非常有价值。
钢筋混凝土框架结构国内外研究方法
钢筋混凝土框架结构国内外研究方法English.Introduction.Reinforced concrete frame structures (RCFSs) are widely used in various construction projects due to their high strength, durability, and adaptability. The research on RCFSs has been a continuous effort, and numerous methods have been developed for their analysis and design. This article provides an overview of the domestic and international research methods for RCFSs.Numerical Methods.Finite Element Method (FEM): FEM is a numerical method that discretizes the structure into finite elements and solves the governing equations at each node. It is widely used for the analysis of RCFSs due to its ability to handle complex geometries and various loading conditions.Boundary Element Method (BEM): BEM is a numerical method that solves the governing equations on the boundary of the structure. It is particularly suitable for the analysis of RCFSs with infinite or semi-infinite domains.Experimental Methods.Static Load Tests: Static load tests involve applying a known load to the RCFS and measuring the resulting deformations and forces. These tests provide valuable insights into the load-bearing capacity, stiffness, and ductility of the structure.Dynamic Load Tests: Dynamic load tests involve applying a time-varying load to the RCFS and measuring the resulting vibrations. These tests are used to study the seismic performance, damping characteristics, and modal frequencies of the structure.Analytical Methods.Linear Elastic Analysis: Linear elastic analysis assumes that the RCFS behaves linearly elastically under load. This method is relatively simple and provides approximate results for small loads and elastic materials.Nonlinear Inelastic Analysis: Nonlinear inelastic analysis considers the nonlinear and inelastic behavior of the RCFS under load. This method provides more accurate results for large loads and inelastic materials.Hybrid Methods.Experimental-Numerical Methods: Experimental-numerical methods combine experimental and numerical techniques to analyze RCFSs. This approach can provide more accurate and reliable results than using either method alone.Model Updating Techniques: Model updating techniques use experimental data to refine and update numerical models of RCFSs. This process enhances the accuracy andreliability of the numerical model.International Research.International research on RCFSs has been conducted extensively in countries such as the United States, Japan, China, and Europe. The following are some key research areas:Development of advanced numerical methods for the analysis of RCFSs.Investigation of the seismic performance of RCFSs.Study of the durability and long-term behavior of RCFSs.Development of sustainable and eco-friendly RCFSs.Domestic Research.Domestic research on RCFSs has also made significant progress in China. The following are some key institutions involved in the research:Tsinghua University.Tongji University.Harbin Institute of Technology.South China University of Technology.Chinese researchers have made notable contributions to:Development of national standards for the design and construction of RCFSs.Development of advanced analysis and design methodsfor RCFSs.Investigation of the seismic performance of RCFSs in major earthquakes.Conclusion.Numerous research methods have been developed for the analysis and design of RCFSs. Numerical methods, experimental methods, analytical methods, and hybrid methods are commonly used, with each offering its strengths and limitations. International and domestic research has contributed significantly to the advancement of knowledge and the development of practical design guidelines for RCFSs.中文回答。
ANSYS在巨型钢框架结构模态分析中的应用_李丙涛
文章编号:1009-6825(2008)08-0094-03ANSYS 在巨型钢框架结构模态分析中的应用收稿日期:2007-10-28作者简介:李丙涛(1982-),男,广西大学土木建筑工程学院硕士研究生,广西南宁 530004谢肖礼(1963-),男,博士后,博士生导师,研究员,广西大学土木建筑工程学院,广西南宁 530004张二毛(1982-),男,广西大学土木建筑工程学院硕士研究生,广西南宁 530004李丙涛 谢肖礼 张二毛摘 要:对有限元模态分析基本理论及A NSYS 环境下模态分析的过程进行了论述,通过对复杂巨型钢框架结构模态计算分析,得到了此模型的固有频率和相应的振型,为巨型钢框架结构的进一步动力分析提供了依据。
关键词:巨型钢框架,模态分析,固有频率,振型中图分类号:T U 398.9文献标识码:A引言从1885年美国芝加哥建起第一座55m 高的高层钢结构以来,在世界范围内特别是西方发达国家,高层、超高层钢结构工程发展迅猛,冲击和改变了世界建筑工程格局。
当今钢结构建筑的发展方向应该是超高层、大跨度和特殊造型三个方面。
国内以央视新址工程、上海国际贸易中心、广州电视塔以及国家体育场工程最具代表性。
首都、武汉、白云机场以及一些现代化的火车站建筑形式也开始向空间曲线相连、大跨度的方向发展。
然而实际结构总是受到各种动荷载的作用产生振动现象,振动会造成结构因共振或结构疲劳而破坏。
随着钢结构向着超高层、大跨度和特殊造型这三个方面的发展,其内部动应力的分析也越来越复杂。
因此,复杂巨型钢框架结构的固有振动频率及振型计算分析是其整体设计必须解决的问题,进而避免外力频率和结构的固有频率相同或接近,防止共振现象的发生。
1 模态分析的重要性及其理论模态分析的经典性定义是:将线性定常系统振动微分方程组中的物理坐标变换为模态坐标,使方程组解耦,成为一组以模态坐标及模态参数描述的独立方程,以便求出系统的模态参数。
复杂建筑工程造价模型的改进设计与仿真
复杂建筑工程造价模型的改进设计与仿真申婷婷;李斌【摘要】Since the traditional building engineering cost model has the problems of large data processing error and poor cal-culation ability,the structural optimization and algorithm improvement are performed for the construction engineering cost mod-el. The multilayer reasonable control calculation is adopted in optimization stricture to reduce the influence of external conditions on calculation. The construction engineering cost model algorithm is optimized. The multi-dimension theory calculation formula is used to perform the final accounts for the investment estimation,design estimate,revised estimate and construction drawing esti-mate,which can improve the data processing capacity and accuracy. The experimental verification results show that the im-proved construction engineering cost model is suitable for the complex construction engineering,and can get the actual and accu-rate cost results.%为了解决传统建筑工程造价模型存在数据处理误差大以及计算抗性差等问题,对建筑工程造价模型进行结构优化和算法改进处理.提出利用优化结构承接多层的合理控制计算,降低外部条件对计算的影响,优化建筑工程造价模型算法,采用多维度理论计算公式对投资估算、设计概算、修正概算、施工图概算进行统一决算,增加数据处理能力以及准确度.通过实验验证,改进后的建筑工程造价模型适用于复杂建筑工程,并能够得到真实准确的造价结果.【期刊名称】《现代电子技术》【年(卷),期】2018(041)008【总页数】4页(P45-48)【关键词】复杂建筑;模型结构;模型算法;改进ECM算法;工程造价;模型设计【作者】申婷婷;李斌【作者单位】广西科技大学鹿山学院,广西柳州545616;广西科技大学,广西柳州545006【正文语种】中文【中图分类】TN911.33-34;TN9130 引言使用传统建筑工程造价模型解决复杂建筑工程时会产生数据误差大、计算结果影响因素多的不足，造成提供数据不准确、可信度降低、施工困难。
洞室开挖稳定分析、如何建设隧洞 外文文献翻译(四篇)
TunnelStability Analysis of Tunnel ExcavationA spillway tunnel for an embankment dam is to be constructed in a poor quality sandstone. The excavated diameter of the tunnel is about 13m and the cover over the roof is 8m. The tunnel is to have a 1.3 m thick un-reinforced concrete lining and , after placement of this lifting, a 28 to high portion of the rockfill dam will he over the constructed tunnel.The questions to be addressed are:(1)What support is required in order to excavate the tunnel safely under the very shallow cover?(2)Is the proposed top heading and bench excavation sequence, using drill and blast methods, appropriate for this tunnel?(3)How will the concrete lining respond to the loading imposed by the placement of 28m of rockfill over the tunnel?In order to answer these questions a series of two-dimensional finite element analyses were carried using the program PHASE'`. The first of these analyses examined the stability and support requirements for the top heading excavation. The final analysis included the entire excavation and support sequence and the placement of the rockfill over the tunnel.The rock mass is a poor quality sandstone that, being close to surface, is heavily jointed. The mechanical properties assumed for this rock mass are a cohesive strength C=0.04Mpa, a friction angle of 40 and a modulus of deformation E =1334 MPa. No in situ stress measurements are available but, because of the location of the tunnel in the valley side, it has been assumed that the horizontal stress normal to the tunnel axis has been reduced by stress relief. The model is loaded by gravity and a ratio of horizontal to vertical stress or 0.5 is assumed.A simplified version of the model was used to analyse the stability and support requirements for the top heading. This model did exclude the concrete lining and the bench excavations.The first model was used to examine the conditions for a full-face excavation of the top heading without any support. This is always a useful starting point in any tunnel support design study since it gives the designer a clear picture of the magnitude of the problems that have to be dealt with.The model was loaded in two stages. The first stage involved the model without any excavations and this was created by assigning the material within the excavation boundary the properties of the surrounding rock mass. This first stage is carried out in order to allow the model to consolidate under gravitational loading. It is required in order to create a reference against which subsequent displacements in the model can be measured.The results of the analysie are illustrated in Figure 18.1, that shown the extent of yield in the rock mass surrounding the top heading, and Figure 18.2 that shows the induced displacements around the tunnel.The large amount of yield in the rock mass overlying the top heading suggests that this excavation will be unstable without support. This view is supported by the displacements shown in Figure I8.2.The reader may be surprised that the displacement in the roof of the tunnel is only 26mm when the extent of the yield zone suggests complete collapse of the roof. It has to be remembered that PHASE is a small strain finite element model and that it cannot accommodate the very large strains associated with the complete collapse of a tunnel. In examining Figure18.2 it is more important to look at the shape of the overall displacement profile than the magnitude of the displacements. A rock mass will not tolerate the differential displacements illustrated and progressive ravelling leading to ultimate collapse would almost certainly result from excavation of an unsupported top heading.A general rule of thumb used by experienced tunnellers is that an underground excavation will not be self-supporting unless the cover over the tunnel exceeds 1.5 times the span of the opening. This is a typical situation that occurs when excavating tunnel portals are there are several options available for dealing with the problem. One of these options is to use a shotcrete lining to stabilize the rock mass above the tunnel. A finite element analysis of this option shows that a 50 mm thick layer of fully hardened shotcrete (uniaxial compressive strength of 30 MPa)is sufficient to stabilize the tunnel. The problem is how to get of shotcrete into an advancing tunnel heading. A second problem is whether the workers would have sufficient confidence in such a solution to work in the tunnel.One project on which this solution was used was the construction of an 8 m span diversion tunnel for a dam. The rock mass was a very weakly cemented limestone that could be excavated by hand but which had sufficient strength that it was marginally self-supporting. The Scandinavian contractor on the project had used shotcrete for many years and the very experienced tunnellers had complete confidence in working under a cover of shotcrcte. The tunnel was not on the critical path of the project and so construction could proceed at a sufficiently slow pace to allow the shotcrete to set before the next advance. A layer of un-reinforced shotcrete was the sole support used in this tunnel, with occasional steel sets embedded in the shotcrete where ground conditions were particularly difficult.In the case of the top heading in sandstone under consideration here, the shotcrete solution was rejected because, in spite of the finite element analysis, the designers did not have sufficient confidence in the ability of the shotcrete layer to support the large span of blocky sandstone. In addition, the contractor on this dam project did not have a great deal of experience in using shotcrete in tunnels and it was unlikely that the workers would have been prepared to operate under a cover of shotcrete only.Another alternative that is commonly used in excavating tunnel portals is to use steel sets to stabilise the initial portion of the tunnel under low cover. This solution works well in the case of small tunnels but, in this case, a 13 m span tunnel would require very heavy sets. An additional disadvantage in this case is that the installation of sets would permit too much deformation in the rack mass. This is because the steel sets are a passive support system and they only carry a load when the rock mass has deformed onto the sets. Since this tunnel is in deformation of a dam, excessive deformation is clearly not acceptable because of the additional leakage paths which would be created through the rock mass.The solution finally adopted was "borrowed" from the mining industry where untensioned fully grouted dowels are frequently used to pre-support the rock mass above underground excavations. In this case, a pattern 3 mx3 m pattern of 15 m long 60 ton capacity cables were installed from the ground surface before excavation of the top heading was commenced. Whenthese cables were exposed in the excavation, face plates were attached and the excess cable length was cut off. In addition, a 2 m x 2 m pattern of 6 m long mechanically anchored rockbolts were installed radially from the roof of the top heading.The results of an analysis of this support system are illustrated in Figure 18.3 and Figure 18.4 which show the extent of the yield zone and the deformations in the rock mass above the top heading.Comparing Figure 18.1 and Figure 18.3 shows that the extent of the yield zone is only reduced by a small amount by the enstallation of the support system. This is not surprising since some deformation of the rock mass is required in order to mobilize the supporting loads in the untensioned cables. This deformation occurs as a result of failure of the rock mass.Figure 18.4 shows that the displacements in the roof of the top heading have been reduced substantially as a result of the placement of the support. However, a small problem remains and that is the excessive displacement of the rock between the rockbolt faceplates which are spaced on a 2 m x 2 m grid. Unless this displacement is controlled it can lead toprogressive ravelling of the rock mass.Only a small surface pressure is required to control this ravelling and this could be achieved by means of a layer of mesh or shotcrete of by the installation of light steel sets. In this case the latter solution was adopted because of the sense of security which these gave for the workers in the tunnel.洞室开挖稳定分析某土石坝工程在质量差的砂岩区开挖溢洪隧洞。
(整理)土木工程专业英语--钢结构.
钢结构专业英语术语2009-09-16 17:57acceptable quality 合格质量acceptance lot 验收批量aciera 钢材admixture 外加剂against slip coefficient between friction surface of high-strength bolted connection 高强度螺栓摩擦面抗滑移系数aggregate 骨料air content 含气量air-dried timber 气干材allowable ratio of height to sectional thickness of masonry wall orcolumn 砌体墙、柱容许高厚比allowable slenderness ratio of steel member 钢构件容许长细比allowable slenderness ratio of timber compression member 受压木构件容许长细比allowable stress range of fatigue 疲劳容许应力幅allowable ultimate tensile strain of reinforcement 钢筋拉应变限值allowable value of crack width 裂缝宽度容许值allowable value of deflection of structural member 构件挠度容许值allowable value of deflection of timber bending member 受弯木构件挠度容许值allowable value of deformation of steel member 钢构件变形容许值allowable value of deformation of structural member 构件变形容许值allowable value of drift angle of earthquake resistant structure抗震结构层间位移角限值amplified coefficient of eccentricity 偏心距增大系数anchorage 锚具anchorage length of steel bar 钢筋锚固长度approval analysis during construction stage 施工阶段验算arch 拱arch with tie rod 拉捍拱arch—shaped roof truss 拱形屋架area of shear plane 剪面面积area of transformed section 换算截面面积aseismic design 建筑抗震设计assembled monolithic concrete structure 装配整体式混凝土结构automatic welding 自动焊接auxiliary steel bar 架立钢筋Bbackfilling plate 垫板balanced depth of compression zone 界限受压区高度balanced eccentricity 界限偏心距bar splice 钢筋接头bark pocket 夹皮batten plate 缀板beam 次梁bearing plane of notch 齿承压面bearing plate 支承bearing stiffener 支承加劲bent-up steel bar 弯起钢block 砌块block masonry 砌块砌体block masonry structure 砌块砌体结构blow hole 气孔board 板材bolt 螺栓bolted connection (钢结螺栓连接bolted joint (木结螺栓连接bolted steel structure 螺栓连接钢结构bonded prestressed concrete structure 有粘结预应力混凝土结构bow 顺弯brake member 制动构件breadth of wall between windows 窗间墙宽度brick masonry 砖砌体brick masonry column 砖砌体柱brick masonry structure 砖砌体结构brick masonry wall 砖砌体墙broad—leaved wood 阔叶树材building structural materials 建筑结构材料building structural unit 建筑结构单元building structure 建筑结构built—up steel column 格构式钢柱(51 bundled tube structure 成束筒结构burn—through 烧穿butt connection 对接butt joint 对接butt weld 对接焊缝Ccalculating area of compression member 受压构件计算面积calculating overturning point 计算倾覆点calculation of load-carrying capacity of member 构件承载能力计算camber of structural member 结构构件起cantilever beam 挑梁cap of reinforced concrete column 钢筋混凝土柱帽carbonation of concrete 混凝土碳化cast-in—situ concrete slab column structure 现浇板柱结构cast-in—situ concrete structure 现浇混凝土结构cavitation 孔洞cavity wall 空斗墙cement 水泥cement content 水泥含量cement mortar 水泥砂浆characteristic value of live load on floor or roof 楼面、屋面活荷载标准值characteristic value of wind load 风荷载标准值characteristic value of concrete compressive strength混凝土轴心抗压强度标准值characteristic value of concrete tensile strength 混凝土轴心抗拉标准值characteristic value of cubic concrete compressive strength混凝土立方体抗压强度标准值characteristic value of earthquake action 地震作用标准值characteristic value of horizontal crane load 吊车水平荷载标准值characteristic value of masonry strength 砌体强度标准值characteristic value o f permanent action· 永久作用标准值characteristic value of snow load 雪荷载标准值characteristic value of strength of steel 钢材强度标准值characteristic value of strength of steel bar 钢筋强度标准值characteristic value of uniformly distributed live load均布活标载标准值characteristic value of variable action 可变作用标准值characteristic value of vertical crane load 吊车竖向荷载标准值characteristic value of material strength 材料强度标准值checking section of log structural member·，原木构件计算截面chimney 烟囱circular double—layer suspended cable 圆形双层悬索circular single—layer suspended cable 圆形单层悬索circumferential weld 环形焊缝classification for earthquake—resistance of buildings· 建筑结构抗震设防类别clear height 净高clincher 扒钉coefficient of equivalent bending moment of eccentrically loadedsteel member (beam-column) 钢压弯构件等效弯矩系数cold bend inspection of steel bar 冷弯试验cold drawn bar 冷拉钢筋cold drawn wire 冷拉钢丝cold—formed thin—walled section steel 冷弯薄壁型cold-formed thin-walled steel structure· 冷弯薄壁型钢结构cold—rolled deformed bar 冷轧带肋钢筋column bracing 柱间支撑combination value of live load on floor or roof 楼面、屋面活荷载组合值compaction 密实度compliance control 合格控制composite brick masonry member 组合砖砌体构件composite floor system 组合楼盖composite floor with profiled steel sheet 压型钢板楼板composite mortar 混合砂浆composite roof truss 组合屋架composite member 组合构件compound stirrup 复合箍筋compression member with large eccentricity· 大偏心受压构件compression member with small eccentricity· 小偏心受压构件compressive strength at an angle with slope of grain 斜纹承压强度compressive strength perpendicular to grain 横纹承压强度concentration of plastic deformation 塑性变形集中conceptual earthquake—resistant design 建筑抗震概念设计concrete 混凝土concrete column 混凝土柱concrete consistence 混凝土稠度concrete folded—plate structure 混凝土折板结构concrete foundation 混凝土基础concrete mix ratio 混凝土配合比concrete wall 混凝土墙concrete-filled steel tubular member 钢管混凝土构件conifer 针叶树材coniferous wood 针叶树材connecting plate 连接connection 连接connections of steel structure 钢结构连接connections of timber structure 木结构连接consistency of mortar 砂浆稠度constant cross—section column 等截面柱construction and examination concentrated load 施工和检修集中荷载continuous weld 连续焊缝core area of section 截面核芯面积core tube supported structure 核心筒悬挂结构corrosion of steel bar 钢筋锈蚀coupled wall 连肢墙coupler 连接器coupling wall—beam 连梁coupling wall—column... 墙肢coursing degree of mortar 砂浆分层度cover plate 盖covered electrode 焊条crack 裂缝crack resistance 抗裂度crack width 裂缝宽度crane girder 吊车梁crane load 吊车荷载creep of concrete 混凝土徐变crook 横弯cross beam 井字梁cup 翘弯curved support 弧形支座cylindrical brick arch 砖筒拱Ddecay 腐朽decay prevention of timber structure 木结构防腐defect in timber 木材缺陷deformation analysis 变形验算degree of gravity vertical for structure or structural member·结构构件垂直度degree of gravity vertical for wall surface 墙面垂直度degree of plainness for structural member 构件平整度degree of plainness for wall surface 墙面平整度depth of compression zone 受压区高度depth of neutral axis 中和轴高度depth of notch 齿深design of building structures 建筑结构设计design value of earthquake-resistant strength of materials材料抗震强度设计值design value of load—carrying capacity of memb ers· 构件承载能力设计值designations 0f steel 钢材牌号design value of material strength 材料强度设计值destructive test 破损试验detailing reinforcement 构造配筋detailing requirements 构造要求diamonding 菱形变形diaphragm 横隔板dimensional errors 尺寸偏差distribution factor of snow pressure 屋面积雪分布系数dog spike 扒钉double component concrete column 双肢柱dowelled joint 销连接down-stayed composite beam 下撑式组合粱ductile frame 延性框架dynamic design 动态设计Eearthquake-resistant design 抗震设计earthquake-resistant detailing requirements 抗震构造要effective area of fillet weld 角焊缝有效面积effective depth of section 截面有效高度effective diameter of bolt or high-strength bolt·螺栓(或高强度螺有效直径effective height 计算高度effective length 计算长度effective length of fillet weld 角焊缝有效计算长度effective length of nail 钉有效长度effective span 计算跨度effective supporting length at end of beam 梁端有效支承长度effective thickness of fillet weld 角焊缝有效厚度elastic analysis scheme 弹性方案elastic foundation beam 弹性地基梁elastic foundation plate 弹性地基板elastically supported continuous girder· 弹性支座连续梁elasticity modulus of materials 材料弹性模量elongation rate 伸长率embedded parts 预埋件enhanced coefficient of local bearing strength of materials·局部抗压强度提高系数entrapped air 含气量equilibrium moisture content 平衡含水率equivalent slenderness ratio 换算长细比equivalent uniformly distributed live load· 等效均布活荷载effective cross—section area of high-strength bolt· 高强度螺栓的有效截面积effective cross—section area of bolt 螺栓有效截面面积euler's critical load 欧拉临界力euler's critical stress 欧拉临界应力excessive penetration 塌陷Ffiber concrete 纤维混凝仁filler plate 填板门fillet weld 角焊缝final setting time 终凝时间finger joint 指接fired common brick 烧结普通砖fish eye 白点fish—belly beam 角腹式梁fissure 裂缝flexible connection 柔性连flexural rigidity of section 截面弯曲刚度flexural stiffness of member 构件抗弯刚度floor plate 楼板floor system 楼盖four sides edge supported plate 四边支承板frame structure 框架结构frame tube structure 单框筒结构frame tube structure 框架—简体结构frame with sidesway 有侧移框架frame without sidesway 无侧移框架flange plate 翼缘friction coefficient of masonry 砌体摩擦系数full degree of mortar at bed joint 砂浆饱满度function of acceptance 验收函数Ggang nail plate joint 钉板连接glue used for structural timber 木结构用胶glued joint 胶合接头glued laminated timber 层板胶合木glued laminated timber structure 层板胶合结构girder 主梁grip 夹具girth weld 环形焊groove 坡口gusset plate 节点Hhanger 吊环hanging steel bar 吊筋heartwood 心材heat tempering bar 热处理钢筋height variation factor of wind pressure 风压高度变化系数helical weld 螺旋形僻缝high—strength bolt 高强度螺栓high—strength bolt with large hexagon head 大六角头高强度螺栓high—strength bolted bearing type join 承压型高强度螺栓连接，high—strength bolted connection 高强度螺栓连接high—strength bolted friction—type joint 摩擦型高强度螺栓连接high—strength bolted steel structure 高强螺栓连接钢结构hinge support 铰轴支座hinged connection 铰接hingeless arch 无铰拱hollow brick 空心砖hollow ratio of masonry unit 块体空心率honeycomb 蜂窝hook 弯钩hoop 箍筋hot—rolled deformed bar 热轧带肋钢筋hot—rolled plain bar 热轧光圆钢筋hot-rolled section steel 热轧型hunched beam 加腋梁Iimpact toughness 冲击韧性impermeability 抗渗性inclined section 斜截面inclined stirrup 斜向箍筋incomplete penetration 未焊透incomplete fusion 未溶合incompletely filled groove 未焊满indented wire 刻痕钢丝influence coefficient for load—bearing capacity of compression member 受压构件承载能力影响系数influence coefficient for spacial action 空间性能影响系数initial control 初步控insect prevention of timber structure 木结构防虫inspection for properties of glue used in structural member结构用胶性能检验inspection for properties of masonry units 块体性能检验inspection for properties of mortar 砂浆性能检验inspection for properties of steelbar 钢筋性能检验integral prefabricated prestressed concrete slab—column structure 整体预应力板柱结构intermediate stiffener 中间加劲intermittent weld 断续焊缝Jjoint of reinforcement 钢筋接Kkey joint 键连接kinetic design 动态设计knot 节子。
模态分析中约束方式对结果的影响
模态分析中约束方式对结果的影响李如忠中国工程物理研究院电子工程研究所，621900刚海燕四川绵阳万博实验学校，621900[ 摘要 ] 利用有限元分析软件Ansys，对一个电子设备中使用的腔体进行了模态分析，通过设置不同的固定方式（约束方式），计算了腔体的固有频率和振型，并对不同约束方式所得的结果进行了比较，确定最符合实际的结果。
[ 关键词]模态分析、固有频率、振型、有限元A Influence Analyse of the Results Given DifferentLoading Conditions in Modal AnalysisLiruzhongInstitute of Electronic Engineering, China Academy of Engineering Physics,621900GanghaiyanMianyang Wanbo Experimental School, Sichuan,621900 [ Abstract ] A modal analysis of a model cavity body used in electronic facility using the ANSYS FEA(Finite Element Analysis)software program is presented. The natural frequencies andmode shapes of the cavity body are determined given different loading conditions, thecomparison of results given different loading conditions is done, and the most valid result isgained.[ Keyword ] modal analysis , natural frequencies, mode shapes, FEA1前言模态分析在结构有限元分析中是一种非常重要的分析，可以通过模态分析获得零件的各阶固有频率和振型，并且模态分析也是动力学分析的基础，在进行瞬态动力学分析、谐响应分析、谱分析等动力学分析时，必须首先进行模态分析。
复杂结构弹塑性时程分析在ABAQUS软件中的实现_汪大绥 (1)
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1 ABAQUS 单元模型[ 10] 1.1 梁柱单元模型(钢梁柱 、混凝土梁柱及组合柱)
采用纤维单元模型 , 基本假定为平截 面假定 , 单元 的特点如下 :1)Timoshenko 梁 , 考 虑剪 切变形 ;2)可采 用弹塑性损伤模型本构关系 ;3)转角和位 移分别插值 , 是 C0 单元 , 容易和同样是 C0 单元的壳元连接 ;4)二次 插值函数 , 长度 方向 有三个 高斯 积分点 , 精度 高 ;5)在 梁 、柱截面设有多个积分 , 用于反映截面的 应力应变关 系 ;6)采用 Green 应变公式 , 考虑大应变的特点 ,适合模 拟梁柱在大震作用下进入塑性的状态 。
因此实际结构模型中应避免单元尺寸过小从而造成计算用时不合理增加个数量级但显式算法不需矩阵求逆及平衡迭代因而每一步的求解时间很短而且其求解时间的增长与结构自由度的增长成正比求解过程中不存在收敛性问题
第 37 卷 第 5 期
建 筑 结 构
2007 年 5 月
复杂结构弹塑性时程分析在 ABAQUS 软件中的实现
显式算法的稳定 步长 通常 比隐 式的 小 2 ～ 3 个数 量级[ 1, 4] , 但显式算法不需 矩阵求 逆及平 衡迭 代 , 因而 每一步的求解时 间很 短 , 而且 其求 解时间 的增 长与结 构自由度的增长 成正 比 , 求解 过程 中不存 在收 敛性问 题 。因此 , 对规模 较大的 弹塑 性模型 进行弹 塑性 时程 分析时 , 显式 算法具 有无可 比拟 的优越 性 。基于 以上 原因 , 下面的弹塑性时程分析中采用显式算法 。 4 工程计算实例
土木工程结构模态参数识别-理论,实现与应用
土木工程结构模态参数识别－理论、实现与应用中文摘要土木工程结构模态参数识别-理论、实现与应用的课题研究来源于国家自然科学基金项目（批准号：50378021）。
土木工程结构是国家基础设施的重要组成部分，直接影响人民的生活和安全。
对土木工程结构进行全面的检测、评估和健康监测，就需要充分了解土木工程结构的动力特征参数。
模态参数是决定结构动力特征的主要参数，其识别方法一般可分为传统的模态参数识别方法和环境激励下的模态参数识别方法。
环境激励振动试验，具有无需贵重的激励设备，不打断结构的正常使用，方便省时等显著的优点，更加适合土木工程结构的实际使用。
环境振动试验不同于传统的基于输入和输出的模态参数识别，仅测得了结构振动响应的输出数据，而真正的输入是没有测量的，是仅基于输出数据的模态参数识别。
成为目前工程结构系统识别十分活跃的研究课题，也是一种挑战。
本文主要研究了环境激励情况下，土木工程结构的模态参数识别问题。
对频域的峰值法和时域的随机子空间识别的理论算法、计算机实现和实际应用进行了深入的研究。
完成的主要工作和结论如下：1.系统地讨论了环境激励情况下模态参数识别频域方法，重点研究了峰值法和频域分解法，对峰值法改进的途径进行了研究，建议采用平均正则化功率谱，并借助传递函数幅角辅助进行峰值选取，使峰值的选取更加客观准确。
频域分解法本质上是基于奇异值分解的峰值法，可以比较客观的选择特征频率和识别相近的模态，识别精度高，是目前较先进的频域识别方法。
2.详细讨论了时域随机子空间识别基本理论和算法，包括协方差驱动随机子空间识别和数据驱动随机子空间识别。
提出了基于稳定图的平均正则化稳定图算法，辅助进行模态参数的自动识别，适应大型土木工程结构分组测试的特点。
平均正则化稳定图将不同阶数模型计算的结果综合考虑，提高识别效率和识别精度。
分析比较表明，协方差驱动和数据驱动随机子空间方法都可以有效识别结构的模态参数，数据驱动随机子空间方法理论上会比协方差驱动随机子空间方法识别结果更稳定、更精确，但计算时间相对要长些。
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Modal Analysis of Construction Hoist Based onANSYSZhang bo 1School of Mechanical Engineering and AutomationXihua University, XHUChengdu, China zbo1985@Qin xiaoyu 1School of Mechanical Engineering and AutomationXihua University, XHUChengdu, China qxy01@Abstract —The dynamic stress caused by vibration when construction hoist is working may cause the structure damage, so the dynamic analysis is an essential part in the design of construction hoist. This paper establish a dynamic model of construction hoist by ANSYS, then conduct modal analysis, and get the first 6 natural frequency and vibration modes.Keywords-construction hoist, ANSYS, model analysis, natural frequency, vibration modeI. I NTRODUCTIONConstruction hoist is an essential vehicle in buildingoperations. Along with the development of the technology and economy, skyscrapers are emerging one after another. The demand for construction hoist is increased greatly. At the same time, the safety of construction hoist is also put forward higher requirements. The enormous dynamic stress caused by the dynamic load which is produced when construction hoist is working may damage the hoist. Dynamics analysis is usually divided into two parts: the modal analysis (i.e., solving the natural frequency and the vibration mode of the system) and the dynamic analysis at certain loads. This paper sets up a dynamic model of SC200-200 type construction hoist by ANSYS, conducts modal analysis, and gets the dynamic characteristic parameters: the first six natural frequency and vibration modes. The results provide the reference for the structure optimization design and the vibration stability analysis of construction hoists.II.BASIC THEORYS OF ANSYS MODELANALYSISThe motion equation of elastic system with limited degrees of freedom (DOF), which can be derived from virtual work principle of dynamic load, the matrix is:()MXCX KX F t ++= （1） Where: M is the mass matrix; C is damping matrix; K isstiffness matrix; And X 、X、X is the column vector of displacement, velocity and acceleration of the system, ()F t is the column vector of external force.In modal analysis, we assume that the system is free vibration, thus, take ()F t =0; and because the structure damping is small, it has little impact on the natural frequency and vibration mode, so it is negligible. Then the un-damped free vibration equation of the system is obtained: 0MXKX += （2）This is a homogeneous system of linear differential equation with constant coefficient, the solution is:0cos X X t ω=（3）Where: ωis the natural frequency of the system.Substituting equation （3） into equation （2）, we will get a homogeneous system of linear equation like this:2000KX MX ω-=（4）A sufficient and necessary condition that equation (4) exist nonzero solution is the determinant of coefficient equaling to zero, that is:20K M ω-=（5）When the order number of matrix K and M is n, equation (5) is n times real coefficient equation of 2ω, which is called characteristic equation of homogeneous system of linear differential equation with constant coefficient (2), the eigenvalue ω and the eigenvector X 0 of the matrix are the natural frequency and the vibration mode of the system.III. DYNAMIC ANALYSIS MODEL OFCONSTRUCTION HOISTThe basic parameters of SC200-200 type construction hoist: Maximum lifting height: 150m; Cage size: 3×1.3×2.3m; Standard section height: 1.508m; Distance between the frameworks adhering to wall: 9m; Material: Q235, Modulus of elasticity EX: 2.01E11Pa, Poisson ratio PRXY: 0.3; Density ： 7800kg/m 3.A. Establish the finite element modelBecause the guide frame and the framework adhering to wall of construction hoist are truss structure, this paper use the BEAM188 element to simulate the guide frame of the construction hoist, use BEAM44 element to simulate thecage structure. In the process of creating the finite element model of construction hoist, we can use DO command to complete some repetitive work, which will make the code more concise. The structure of construction hoist is enormous and complex, it should be simplified properly: the local structure which impact on the results little should be ignored. Construction hoist is assembled by identical standard sections and frameworks adhering to wall, thus, we just need to establish a standard section and a framework adhering to wall model, and the rest of the standard sections and the frameworks adhering to wall can be created by the copy command. The finite element modal for model analysis of construction hoist is as follow:Figure 1. Finite element model of construction hoistB. Boundary conditionConstruction hoist is fixed on the ground, thus all the degrees of freedom of the bottom of construction hoist guide frame should be constrained; the connection between the framework adhering to wall and the wall is hinge joint, thus the X, Y, Z direction displacement freedom and the Y, Z direction of the rotational degree of freedom of the framework adhering to wall should be constrained. The connections between components of construction hoist are not solid connections, thus, they must be connected with coupling restrained in the model. The framework adhering to wall, the cage and the guide track should be connected by coupling in the model. Figure 2 shows the coupling between the framework adhering to wall, the cage and the towerbody.Figure 2. Coupling between framework adhering to wall, cage and towerbodyIV. LOAD AND SOLVEThe vibration is assumed to be free vibration in modal analysis, therefore, the external loads, such as cage load and wind load, can be ignored. The only effective "load" in modal analysis of construction hoist -- its own gravity load can be defined by the material density and the acceleration of gravity.ANSYS12.0 provides seven kinds of modal extraction method for customers, they are: Block Lanczos, PCG Lanczos, Reduced, Unsymmetric, Damped, QR Damped and Super node. The Block Lanczos method calculate more quickly , don’t need input many parameters, and it ’s eigenvalues and eigenvectors with higher precision, especially suitable for solving large symmetric eigenvalues problems. This paper adopts Block Lanczos method. We i nput “6” in the blank after “No. Of modes to extract ” to extract the constructi on hoist’s first 6 vibration mod es, and choose modal expansion to provide standardized model shape for Block Lanczos method.V.RESULTSIt is the low order natural frequency that influence the dynamic response of construction hoist, rather than the high order natural frequency. So this paper only extracts the first6 vibration modes, as shown in figure 3~8:Figure 3.First vibration modeFigure 4.Second vibration modeFigure 5.Third vibration modeFigure 6.Fourth vibration modeFigure 7.Fifth vibration modeFigure 8. Sixth vibration modeTable 1 lists the natural frequency and vibration modes of construction hoist:TABLE I.T HE NATURAL FREQUENCY AND VIBRATION MODES OFCONSTRUCTION HOISTOrder Natural Frequency (Hz)Vibration Mode (m)1 3.183 0.0506142 5.379 0.0661363 5.844 0.015998 4 5.875 0.015985 55.925 0.016008 65.9930.016006From figure 3~8 and table 1, we can know that: when the cage at the top of construction hoist, the first-order natural frequency of the system is 3.183Hz, and the amplitude is 0.050614m; the second-order natural frequency of the system is 5.379Hz, and the amplitude is 0.066136m; the third-order natural frequency of the system is 5.844Hz, and the amplitude is 0.015998m. The natural frequency of the system changes little and tends to 6Hz after the second-order; the amplitude obviously decreases and tends to 0.016m from the third-order. Which conform that it is the low order natural frequency rather than the higher that influence the dynamic response of construction hoist.VI. CONCLUSIONSThis paper conducts the model analysis of construction hoist by the finite element analysis software ——ANSYS, find that the minimum natural frequency is the first one, it is 3.183Hz; and the first two order amplitudes are larger than the higher, and the largest amplitude is the second one, it is 0.066136m. The natural frequency after second-order tends to 6Hz; and the amplitude significantly decreased and tends to 0.016m from the third-order. These results confirm that it is the low order natural frequency that influence the dynamic response of construction hoist, rather than the high order natural frequency.REFERENCES[1]Xin Yan，Luo Ji-man，Wang Dong-hong, Chen Hao. Modal analys-is of construction hoist [J].Construction mechanization.Mar.2009:27-39[2]Zheng Pei，Zhang Qing，Lu Yao-zu. Structural modeling andanalysis of super-high building hoist [J]. Engineering Journal of Wuhan University，Jun.2009. Vol.42,No.3:353-381[3]Yin Qiang，Chen Shi-jiao，Ji man-zhong. 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