客车侧翻试验仿真研究

为检验某大型客牟上部结构强度性能，依照GB/T17578-1998《客车上部结构强度的规定》进行了客车实车侧翻试验，在此基础上应用ANSYS／LS—DYNA软件建立客车侧翻试验有限元模型并进行仿真。通过比较，仿真分析与实车试验得到的车身变形趋势基本一致，在数值上仿真结果略高于试验值，从而验证了有限元建模仿真结果的正确性。     

某大型全铝全承载城市客车车体骨架设计开发

建立了某钢制全承载城市客车车体骨架的有限元模型,通过模态试验验证了其准确性。在钢制客车几何模型和有限元模型的基础上进行全铝车体骨架结构转化和灵敏度分析,找出对铝制客车性能参数影响较大的零部件,依据灵敏度分析结果搭建优化设计数学模型,代入基于Opti Struct求解器模块的优化软件中进行迭代优化。实车模态试验验证结果表明,优化后的全铝车体骨架在性能参数不低于钢制车体骨架的情况下,实现了38.5%的轻量化效果。     

基于侧翻试验的客车骨架结构改进

客车上部结构强度越来越引起客车行业的重视。通过建立有限元模型,对某客车上部结构强度进行仿真分析,找出骨架薄弱结构并予以改进,并依据ECE R66法规进行侧翻试验,验证了改进后结构的合理性,更好地保证了乘客的生存空间。     

《客车上部结构强度》等效认证方法之——车身截段准静态负荷试验方法研究

我国正以ECER66号法规为基础，对GB17578-1998（（客车上部结构强度》进行修订，修订版在原标准基础上增加了几种等效认证试验方法，车身截段准静态负荷试验方法是等效认证试验方法之一，这里主要通过车身截段准静态负荷试验与实车侧翻试验进行比较以验证该等效认证试验方法的有效性，同时确认该试验方法的可操作性，为GB17578—1998的修订提供依据。     

基于ECE R66法规的客车侧翻碰撞安全性能的仿真与优化

建立了某型号客车的有限元模型,依据欧洲ECE R66法规要求进行了客车动态侧翻碰撞过程的仿真,评价了该车上部结构的变形及其侵入乘员生存空间的状况,仿真分析结果与试验数据一致性较好,说明该有限元模型是准确的.根据多方案仿真结果,对顶横梁、窗立柱等结构进行改进设计,有效提高了其抗变形能力,改善了该车的侧翻安全性能.     

基于有限元法的大型客车模态分析与结构改进

以某大型客车为研究对象,利用有限元技术建立客车有限元模型对车体进行自由模态分析,得出客车骨架的固有频率和振型;通过对计算结果的分析,指出了该客车骨架设计的不足之处,并提出了改进方案。     

微型客车车身结构正面碰撞特性的数值模拟

研究了某微型客车的有限元建模及数值模拟方法，并对该客车的正面碰撞特性进行了数值模拟分析，最后进行了相应的试验验证。模拟与试验结果吻合较好，表明所采用的数值模拟方法基本正确。该方法可用于该微型客车的开发和改进。     

GL6460L轻型客车的翻滚碰撞安全性

采用有限元仿真分析方法,建立了GL6460L轻型客车的翻滚碰撞安全性有限元模型,应用软件LS-DYNA模拟其车身骨架翻滚过程,验证该客车能满足GB/T17578<客车上部结构强度的规定>的要求.     

紧急制动对客车车体强度的影响

对钢板弹簧悬架和直通大梁式车架的客车的制动载荷进行了模拟，建立了国产某轻型客车的车体结构有限元分析模型，分析了制动载荷对车体强度和刚度的影响。     

基于有限元法的客车顶部安全性试验分析

建立了某轻型客车车体结构详细的有限元模型。按照国标规定的试验要求分析了该轻型客车顶部承受静载荷时结构的整体刚度和各门窗处的开口变形情况。计算结果表明该车的顶部静压刚度良好，同时也验证了利用有限元法进行客车顶部静载安全性虚拟试验的可行性。     

Load Transfer Analysis of a Bus Bay Section Under Standard Rollover Test Using <Emphasis Type="Italic">U</Emphasis>*<Subscript>M</Subscript> Index

Bus rollover accidents are receiving increasing attention due to the associated high fatality rate. In order to improve the bus structural performance during the rollover collision, it is necessary to investigate how the impact force is transferred within the bus superstructure. This paper introduced a method for studying the load transfer behavior of the bus superstructure during the standard rollover test by using the U * _M index. A bus bay section was used as the sample structure to demonstrate the proposed method. The result of the paper reveals that the load transfer analysis based on the U * _M index can provide engineers with the insight of the structural issues and the direction to improve the structural performance, which cannot be accomplished through the conventional finite element analysis.     

Methodology for bus structure torsion stiffness and natural vibration frequency prediction based on a dimensional analysis approach

Engineering bus design requires testing of bus structures prototypes in order to guarantee a certain level of strength and an appropriate static and dynamic behavior of the bus superstructure when exposed to road loads. However, experimental testing of real bus structures is very expensive as it requires expensive resources and space. If testing is done on a scale bus model the previous required expenses are considerably reduced. Therefore, a novel methodology based on dimensional analysis applied to bus structure prediction to evaluate the bus structure static and dynamic performance is proposed. The static performance is evaluated attending to torsion stiffness and the dynamic in terms of the natural vibration frequencies and rollover threshold. A scale bus has been manufactured and dimensionless parameters have been defined in order to project the results obtained in the scale bus model to a larger model. Validation of the proposed methodology has been carried out under experimental and finite element analysis.     

Optimization of bus rollover strength by consideration of the energy absorption ability

Buses are an integral part of the national transportation system of each country. A rollover event is one of the most important hazards that concerns the safety of the passengers and the crew in a bus. In the past, it was observed after the accident that the deforming superstructure seriously threatens the lives of the passengers. Thus, the stiffness of the bus frame is the first thing that needs to be considered. The unfortunate side of strengthening the bus superstructure is that it usually causes the bus weight to increase. This paper presents an efficient and robust analysis method with which to design the bus superstructure for a reduction in occupant injuries from rollover accidents while the weight of the strengthened bus is maintained at the same level. First, the absorbed energy of the bus frame and its components during a rollover were investigated by using a LS-DYNA numerical study. The highest energy absorption region, which is the side section of the bus frame, was found and focused on for the investigation of a means to re-distribute the energy-absorption ability of the side frame component. Then the thickness parameters that were obtained from the re-distribution of the energy-absorption ability were used in the analysis to optimize the design. Finally, a prototype of the bus with a reasonable thickness for the window pillars and the side wall bars, which was based on the optimized parameters, was verified to ensure it satisfied ECE R66. In this paper, an effective usage of materials and an efficient and robust analysis method were presented to design the bus superstructure. Although the optimization process for increasing the stiffness is simple, this study improves the upper displacement by 39.9% and the lower displacement by 49.3% (versus the bus survivor space) while maintaining the bus weight at the existing level.     

超高车辆-桥梁上部结构撞击力的工程计算方法

为了弥补中国在超高车辆撞击桥梁上部结构领域研究的不足,完善其工程设计方法,在超高车辆撞击桥梁上部结构的事故案例调查和精细化有限元分析的基础上,提出了超高车辆-桥梁上部结构撞击的简化计算模型,建立了简化模型的微分方程组,利用数值试验的方法确定了简化模型中的部分参数,从而得出简化计算模型的撞击荷载;为了满足工程设计的需要,在简化模型的基础上提出了形式简单的撞击力设计公式,以表格的形式给出了设计公式中基本参数的主要取值,并将简化模型和设计公式的计算结果与有限元结果进行了比较。结果表明:根据简化模型和设计公式计算得到的撞击荷载与精细有限元模型的计算结果吻合较好,且偏于安全,可为工程设计提供参考。     

基于接触非线性的特大吨位球型支座有限元分析

支座是支承和连接桥梁上、下部结构的重要装置.它将上部结构的恒、活载传递给墩台,并根据计算假定适应或者约束上部桥跨结构产生的水平和转角变位.考虑到上部结构为钢桁架结构,球型支座不仅受力巨大且支点受力复杂.将常规放置在上方的球冠衬板倒置,支座水平滑移面从上方移至下方.根据支座结构和桥梁设计支座技术要求,建立支座有限元模型,运用接触分析更精确地对支座进行有限元分析.有限元计算结果表明,支座受力控制构件平面四氟板与曲面四氟板满足设计要求.     

基于流变理论的基坑回填后地下通道变形数值分析

基于流变理论，运用有限元软件ANSYS建立三维有限元模型，并应用EDP弹塑性模型和西原正夫蠕变模型进行模拟分析，研究地下通道回填后时间效应对土体及结构物的变形规律。结果表明:基坑回填完成后，随着基坑支护距离的增大，地表Z向位移逐渐减小，主体上部结构最大X向位移变化不大，约为0.09 mm。土体沉降和上部结构沉降随时间变化规律基本相同，都表现为最大沉降越来越大，变化速率开始很快，随后越来越慢，最后趋于稳定状态。     

混合动力客车侧面耐撞性分析

建立东风EQ6110HEV6混合动力客车和某MPV有限元模型,基于美国公共交通协会(APTA)对侧面碰撞要求,联合HyperWorks和LS-DYNA软件建立了混合动力客车与MPV侧面碰撞的有限元模型,仿真计算了MPV以40km/h的速度从侧面90°撞击该混合动力客车。以该混合动力客车结构变形、各测点加速度值、乘员生存空间侵入量为评价指标,分析了该混合动力客车侧面耐撞性能,为客车碰撞安全性的判定提供参考。     

基于有限元分析的城市客车扶手杆结构改进

基于国内城市客车扶手杆应用的现状,对顶置电池城市客车扶手结构进行了有限元分析,为扶手整体结构的强度、刚度设计提供理论依据。     

客车蒙皮对侧翻碰撞仿真结果的影响

参照ECE/R66法规和我国GB/T17578-1998法规中的相关试验要求,建立了某6120型高床大客车车身骨架有限元模型和带蒙皮的整车车身有限元模型,通过车身立柱变形量和能量吸收情况两项指标,对比分析客车蒙皮对侧翻碰撞仿真分析结果的影响程度.仿真分析结果表明:客车蒙皮在侧翻碰撞仿真分析中对车身前后端立柱的变形量影响...     

Variable Cross-Section Rectangular Beam and Sensitivity Analysis for Lightweight Design of Bus Frame

Timoshenko beam element of variable cross-section rectangular tube is developed and applied in the lightweight design of bus frame in this paper. Firstly, the finite element formulations of variable cross-section beam (VCB) are derived under the loadsteps of axial deformation, torsional deformation and bending deformation. Secondly, bending deformation experiment and its detailed shell finite element model (FEM) simulation of variable cross-section rectangular tube were conducted; and the proposed VCB, detailed shell FEM and experimental results can be highly consistent. Thirdly, VCBs are used to substitute for parts of the uniform ones in a bus frame. An innovatively lightweight bus frame is obtained and all the performance responses are improved simultaneously. Finally, rollover analysis further shows the advantage of variable cross-section bus frame in crashworthiness design.