跨座式轻轨车与连续轨道梁空间振动分析

摘 要：提出了一种跨座式轻轨车与连续轨道梁空间耦合振动时域分析方法。桥梁采用常规有限单元模拟,跨座式轻轨车采用弹簧阻尼相连的多刚体模拟,可方便考虑走行轮、导向轮、稳定轮下轨道不平顺的影响,直接建立轻轨车－桥梁时变系统的空间振动方程,采用直接积分法同时求解轻轨车、桥梁的空间动力响应,并编制了相应的计算分析程序。以一联3×30 m的双线连续轨道梁为例,计算了轻轨车以不同车速通过双线轨道梁时全过程车桥动力响应。探讨了不同车速、单线行车、双线对开等不同工况对车桥动力响应的影响。计算结果表明：在设计行车速度下,轻轨车可安全舒适通过该连续轨道梁;桥梁具有良好的整体刚度。该方法可运用于跨座式轻轨车与其它大跨度桥梁的空间振动分析。     

基于ANSYS的压力机静力与瞬态分析

介绍了一种自行开发设计的压力机的结构、工作原理.针对该结构,运用ANSYS软件机构分析方法 ,计算在工作冲击下,其最大偏动位移和强度.将模型在ANSYS中做瞬态分析,分析该机器的工作情况,振动情况及危险部位等信息.仿真试验结果 表明该结构在实际应用中满足要求.     

电缆拖挂单轨吊运行轨道悬吊安装方法探讨

由于孔庄煤矿地质条件复杂,巷道淋肩角度大,巷道内电缆和管路较多,人工运输电缆和管路不但会造成电缆和管路的人为损坏,而且在运输过程中容易造成意料不到的其他安全事故。为了改变这种落后低效的运输方法,根据井下现场实际情况,本文介绍了孔庄煤矿的井下现状和现在电缆拖挂单轨吊运行轨道悬吊安装方法。     

基于瞬态动力学分析的进气歧管振动响应研究

本文以瞬态动力学理论知识为基础,对某塑料进气歧管进行瞬态动力学分析;仿真分析中,采用发动机全速全负荷工况下的本体时域激励,对进气歧管进行瞬态动力学分析,计算进气歧管谐振腔与节流阀体表面的振动加速度。分析结果表明仿真结果与试验结果基本一致;仿真结果为发动机典型零部件的NVH分析提供了技术支持与理论依据,也为后续振动疲劳分析提供相应的数据支持。     

大件运输车-桥耦合动力学分析

特殊大件运输车货质量可达千吨,在判断大件运输车辆能否安全通过桥梁时,以桥梁跨中挠度作为评判标准关键指标。该文以四川德阳市石亭江大桥为例,采用Auto CAD软件对大桥进行建模,而车辆的模型以尼古拉斯全液压平板车组为模版进行建模,然后在ADAMS软件中对车辆与桥梁进行耦合动力学分析,研究不同轴数、轴距、轴线载荷的大件运输车辆通过桥梁时桥梁跨中挠度的变化情况。建立的模型和分析结果可以用于预估大件运输车辆通过桥梁时的跨中挠度,为大件运输车辆桥梁通过性提供定量分析方法。     

制动电阻器结构瞬态动力分析

采用通用有限元软件 ANSYS6.1对高速行驶列车上使用的制动电阻器结构进行瞬态动力分析,得到电阻器在各个方向冲击栽荷作用下的应力分布、关键部位的内力响应时程曲线,从而保证其运行的抗冲击性和结构的安全性。     

瞬态弹性动力学问题的半解析边界元法

本文用半解析有限元法对边界积分方程作离散化处理,通过引入基本解函数和半解析半离散试函数的二次半解析过程,使三维弹性动力学问题简化为一维数值计算。文中又采用移动边界元法来模拟波在半无限介质中传播的表面积分问题,分析计算了各种瞬态波在介质内传播,绕射及地面运动问题。计算结果表明,半解析边界元法不仅计算精度高,而且工作量大大降低,具有较高的经济效益与应用价值。     

一种适用于成都市内旅游线的悬挂式单轨车造型设计

目的对适用于成都市内旅游线的悬挂式单轨车造型进行设计研究。方法以成都的轨道交通现状为基础,分析交通与城市旅游的关系,对适用于城市内的几种轨道交通型式进行比较,明确了每种型式的优、缺点;然后将车辆造型与城市地域文化元素相结合,形成具有成都特色的旅游线轨道交通车辆造型设计。结论得出悬挂式单轨车更适合用于城市内的观光线路,并提出在成都市内几个重要旅游景点间建设一条悬挂式单轨旅游线路,以成都元素熊猫为题材,设计出一款具有成都地域特色,适合市内旅游线路专用的悬挂式单轨概念车。     

基于多车精细建模的曲线地段重载列车-轨道系统动力性能研究

建立考虑多车效应的重载列车-轨道系统精细化动力分析模型,对车辆、钩缓装置中各种细部构件及部件间接触摩擦等作用机制进行精细模拟,基于Hertz理论及FASTSIM算法进行轮轨接触计算。利用自主研发设备通过现场参数试验进行轨道建模。深入研究重载铁路曲线地段列车-轨道系统动力性能及曲线参数影响规律。结果表明,缓和曲线地段轮轨相互作用规律复杂,列车不同位置车轮受力呈现迥异变化趋势及幅度,前后缓和曲线轮轨相互作用亦完全不同,主要由超高顺坡及车辆构造所致;缓和曲线长度过短可导致超高顺坡过大不利列车运行,缓和曲线长度对动力性能影响曲线往往存在拐点,建议以拐点值限定最小缓和曲线长度;增长缓和曲线可有效减弱轮轨相互作用,并主要通过减缓列车首车及导向轮对磨耗降低整体磨耗;随缓和曲线长度不断增加,对动力性能改善效果越不明显。我国重载铁路小半径曲线超高设置通常偏大,建议适当降低超高值、设置10%~20%欠超高,利于改善轮轨受力、减缓磨耗。增大曲线半径利于减弱轮轨相互作用及磨耗,但半径越大改善作用越小。     

神经网络在轨道动力学中的应用

本文中研究了神经网络在列车轨道动力学中的应用。列车轨道系统的各种参数众多,关系复杂,用模型分析出入较大。为了利用试验数据,分析列车轨道动力特性,本文提供了一种应用神经网络的分析方法。结果表明,用神经网络整理分析试验数据是有效的     

Discrete equivalent time integration methods for transient analysis

It was recently shown in a series of papers that the frequency response of temporally discretized finite element equations and, consequently, the achievable accuracy cannot be manipulated independently in different frequency ranges. In addition, there exist limitations on the achievable accuracy of a time integration method no matter what the order of accuracy of the method is. Motivated by this fact, a family of time integration methods is derived in the time domain based on the principle that the exact solution of the semidiscrete equation of a system and the solution of the time integration method match at discrete time steps. It is necessary to pursue an exact match at discrete time steps, i.e. discrete equivalence, since the solutions of semidiscrete equations are obtained only at the time steps. Two time integration methods, that are exact at the time steps, are obtained based on the impulse and ramp response invariance principles. Numerical examples are presented to show the advantage of the proposed methods and to compare the performance of them with the performance of some popular methods. Copyright © 2003 John Wiley & Sons, Ltd.     

The iterative group implicit algorithm for parallel transient finite element analysis

The Iterative Group Implicit (IGI) algorithm is developed for the parallel solution of general structural dynamic problems. In this method the original structure is partitioned into a number of a subdomains. Each subdomain is solved independently and therefore concurrently, using any traditional direct solution method. The IGI algorithm is an extension of the Group Implicit (GI) algorithm, and similarly to that method compatibility of the interface degrees of freedom is restored using a mass averaging rule. However, unlike the GI algorithm, in the IGI algorithm an iterative procedure is devised to restore equilibrium at the interface degrees of freedom. The IGI method has the same algorithmic characteristics as the underlying solution method used to solve each subdomain. Furthermore, the solution obtained by this method, once the iteration converges, is the same as the one obtained if the subdomain solution method is used to solve the whole structure. Numerical studies are carried out which demonstrate that the performance of the IGI algorithm is superior to that of the GI algorithm both in terms of accuracy and efficiency. Finally, the IGI method is highly modular and scalable, and therefore very well suited for distributed and parallel computing. Copyright © 2000 John Wiley & Sons, Ltd.     

Binary spatial partitioning of the central‐difference time integration scheme for explicit fast transient dynamics

This paper proposes a generalization of the explicit central‐difference time integration scheme, using a time step variable not only in time but also in space. The solution at each element/node is advanced in time following local rather than global stability limitations. This allows substantial saving of computer time in realistic applications with non‐uniform meshes, especially in multi‐field problems like fluid–structure interactions. A binary scheme in space is used: time steps are not completely arbitrary, but stay in a constant ratio of two when passing from one partition level to the next one. This choice greatly facilitates implementation (via an integer‐based logic), ensures inherent synchronization and avoids any interpolations, necessary in other partitioning schemes in the literature, but which may reduce numerical stability. The mesh partition is automatically built up and continuously updated by simple spatial adjacency considerations. The resulting algorithm deals automatically with large variations in time of stability limits. The paper introduces the core spatial partitioning technique in the Lagrangian formulation. Some academic numerical examples allow a detailed comparison with the standard, spatially uniform algorithm. A final more realistic example shows the application of partitioning in simulations with arbitrary Lagrangian Eulerian formulation and fully‐coupled boundary conditions (fluid–structure interaction). Copyright © 2008 John Wiley & Sons, Ltd.     

轮轨磨耗状态下悬挂参数失效对车辆动力学性能影响

为了研究悬挂参数失效对车辆系统动力学性能的影响,建立高速车辆系统动力学模型和悬挂参数失效模型,针对新轮轨、磨耗后轮轨进行轮轨接触几何关系和动力学仿真计算,分析当悬挂参数正常工作和失效时,车辆动力学性能的变化。结果表明：与新轮轨相比,轮轨磨耗状态下的等效锥度、滚动圆半径差和左右轮轨接触角度差变大;轮轨磨耗造成蛇行失稳临界速度下降,运行平稳性和曲线通过能力变差;悬挂系统失效方式不同,对车辆系统动力学的性能和车体的动态响应影响程度不同;车辆的悬挂参数优化应考虑轮轨磨耗的影响。     

异形易碎小型固性物料的转运料装置构型设计与特性试验研究

目的 针对一种易碎异形小型固性物料的添加需求,开发一种物料转运料装置。方法 采用瞬态动力学仿真分析方法,运用ANSYS WorkBench软件对小型固性物料受到冲击碰撞进行瞬态动力学仿真分析,研究其可承受的最大转速。通过搭建平台进行实物转运料试验,验证该装置的可靠性和稳定性,得到为达到生产效益最大化的最优转速。结果 仿真结果表明该物料最大承受转速为1 200 r/min,否则物料失效。结论 根据转运物料试验表明该装置结构设计合理,可满足在高速连续状态下转运料的工作要求,且在600 r/min时物料完好数最多,生产效率最高。     

Failure analysis of three reconditioned rail car couplers

Three reconditioned rail car couplers, arbitrarily identified as couplers, failed during service due to cracking of the front face. The three couplers were reportedly upgraded by quenching and tempering to enhance strength and toughness. The objective of this investigation was to determine the mode of crack propagation and the root cause of the observed failures. Verl E. (Bud) Kahle, P.E., was a professional failure analyst for more than forty years. After receiving his Bachelor of Science degree in physical metallurgy from Washington State University 1957, Bud was employed by the General Electric Company at a facility in Hanford, Washington. He later was employed by the Aerojet General Corporation and eventually was head of the Southern Pacific Materials Science Laboratory in Sacramento. After retirement from Southern Pacific he owned and operated his own firm, Kahle Metallurgical Consulting Services, for fifteen years. He came to be known as “the man with the answers” to clients in a variety of industries. Bud was a Life Member of ASM International. Many of Bud’s clients remarked on the high quality of his failure analysis case histories and encouraged him to have them published. After Bud passed away in 1999, his wife, Suzanne, approached ASM International to see if the society would be interested in publishing any of his work. Mrs. Kahle was able to supply a large number of reports, which Bud had carefully archived over the years. Journal of Failure Analysis and Prevention Associate Editor Michael Stevenson read through the collected case histories, selected the ones to be included in this issue, and edited them for journal publication. ASM International wishes to thank Mrs. Kahle for providing these case histories for publication.     

Simulation of wheel–rail contact forces

This paper summarizes the forces that develop in the contact patch between the wheel and rail in a railway vehicle. The ways that these forces govern the behaviour of a vehicle running on straight and curved track are explained and the methods commonly used to calculate and utilize the forces summarized. As an illustration, the results from a computer simulation of a typical UK passenger train are presented and certain aspects examined.     

移动式架车机伸缩托头-托架接触的有限元分析

采用基于接触对的非线性接触分析处理接触问题时,其分析结果更接近工程应用实际,但计算成本比较高且存在不收敛的情况。而自由度节点耦合分析不但能降低计算成本,而且能够保证一定精度。为了探究在一定误差范围内选用自由度节点耦合分析来替代基于接触对的非线性接触分析的可行性,以举升重量为15 t的移动式架车机为研究对象,在ANSYS软件中建立伸缩托头-托架的接触模型与节点耦合模型,在举升高度最大且伸缩托头完全伸出的工况下进行有限元分析,考虑接触刚度系数与摩擦因数对有限元分析结果的影响,分析了2种模型各接触区域等效应力的区别。通过比较2种模型的有限元分析结果可知,2种模型各接触区域的等效应力值存在一定的相对误差,且接触区域内2个接触面的相对滑动程度决定了接触分析的精度。对于精度要求不高的机械结构,可以考虑用自由度节点耦合分析来替代基于接触对的非线性接触分析。     

扭矩扳手检定装置受力杆结构优化分析

利用ANSYS Workbench对扭矩扳手检定装置受力杆进行静力学分析,模拟其对扭矩扳手进行扭矩值检定时受到应力、应变及变形的情况,根据得到的数据对其进行结构优化设计、轻量化设计。