针对前桥吊臂开裂问题,通过基于轴承座受力的静强度分析方法对前桥进行仿真,并与传统方法仅考虑冲击加速度静强度仿真结果进行对比,结果表明考虑轴承座受力的静强度分析方法对开裂问题判断准确性较高,对比改进前与改进后前桥强度,发现提高前桥壳体支架位置刚度对整体结构抵抗变形能力影响明显,验证优化方案的可靠性.

某越野车预研项目采用全新开发的轻量化全铝合金车架,纵梁采用内高压成型的创新工艺,复杂承载部件采用铸造铝合金,车架整体进行固熔+人工时效热处理工艺.为行业内首次应用的大型铝合金构件,具有国内先进性,同时具有较高的开发难度.以全铝车架的性能开发为目标,运用仿真分析手段进行分析优化及改进,并通过系列试验验证,最终满足性能开发的目标要求.

针对某型车门下沉问题,通过台架试验获得车门、铰链和车身等各单因素下沉量和车门绞链系统整体下沉量,对单因素下沉量与系统整体下沉刚度进行线性拟合分析,得到车门铰链系统各单因素与系统下沉刚度的相关度排序.对前、后车门分别选取相关度较高的单因素进行优化,最终改进方案的仿真和试验结果证明该方案可有效地提升车门下沉刚度.采用定量分析法可快速找出影响下沉刚度的敏感因素,并能够快速生成优化方案,为新车型设计提供参考.

基于多年采集的全国典型和极限路况试验数据,建立了基于动静态载荷强关联技术的28种极限及典型工况载荷分析方法.利用多体动力学模型提取车架28工况载荷受力情况,与有限元分析相结合,对车架进行刚度和强度分析,为车架结构改进提供依据.

针对越野车外覆盖件抗凹分析流程中考察点多、加载工况复杂、工作效率低的现状,采用TCL/TK语言和基于HyperMesh前处理平台,开发一套简单、高效、便捷的可视化CAE抗凹分析自动化流程.该流程主界面简单,可以按照需求自动完成网格细化、压头创建和工况分析,操作简便.以某越野车发动机盖抗凹分析为例,验证该抗凹分析自动化流程的高效率和分析结果的准确性.

针对汽车A柱上端开裂问题,通过基于道路载荷谱的瞬态疲劳分析方法对车身进行疲劳仿真分析,并与静强度仿真分析进行对比,结果表明基于道路载荷的瞬态疲劳分析方法对开裂问题分析准确性较高.对比改进前、后汽车A柱上端仿真结果,二者分析趋势一致,以疲劳分析方法为主、强度分析方法为辅进行仿真,发现结构搭接面积、零件自身刚度、零件过渡圆滑度对整体结构抵抗变形能力的影响明显,为今后车身立柱上端正向设计提供了参考.

外挂式备胎是高性能越野车的标志性配置,在恶劣的高强度越野路况时,备胎支架及铰链承受较大载荷,故备胎支架及尾门铰链强度应在开发时重点考虑.文中以某越野车外挂式备胎结构的备胎支架为例,充分考虑车身尾部及尾门系统的频率特性,采用振动疲劳频域分析方法进行前期设计及方案优化,经24通道轴耦合可靠性试验验证满足强度耐久性能要求,通过继续试验验证了备胎支架开裂位置与仿真分析风险位置的一致性,进一步验证了振动疲劳频域分析方法在外挂式备胎支架的疲劳分析中的有效性和准确性.

Structural optimization technologies are increasingly applied to lightweight automotive structural design. In a body-in-white (BIW) development project, optimization technologies are applied in three steps that are seamlessly integrated into engineering practice. By following a design-driven approach, an innovative design that was 50.65 kg lighter than the base design was achieved. First, topology optimization was used to investigate the optimal material distribution in a given design space, and helped in extracting the main load path, while considering crashworthiness, NVH, and static stiffness performance requirements. In the second step, the effective design of a beam cross-section and feasible joints was carried out based on optimization technology and expert knowledge. In this step, the deep involvement of manufacturing process experts on stamping and joint connection feasibility analysis increased the chance of success remarkably. The sensitivity analysis, topography optimization, and gauge optimization of the created draft 3D BIW frame comprised the last step before finalizing the initial design. The new design was validated by full load case simulations, including full vehicle crashworthiness analysis, mode frequency, and body mount point dynamic stiffness analysis, and BIW stiffness and component attachment stiffness analysis. The validation results indicate that the new BIW design achieves the performance goal, while being 13.3% lighter than the base design.

转向摇臂在进行零部件台架试验时,在最大输出扭矩情况下,需要满足1000万次的疲劳寿命.对台架试验中转向摇臂进行结构性强度分析.通过有限元仿真分析,还原台架试验过程,预测应力集中位置,预估结构疲劳寿命.通过试验对标,修正仿真模型,最终实现转向摇臂的结构优化.

为实现某大型水平轴风力机塔筒法兰螺栓的抗疲劳设计,提出基于Schmidt-Neuper模型的疲劳强度校核方法.由单扇面法兰系统刚度分配比例,建立螺栓内力与外界拉力的非线性关系.通过载荷线性插值得到螺栓时序应力,由雨流计数和累积损伤计算得到整圈螺栓疲劳累积损伤分布,并进一步找到最大累计损伤位置.在此基础上,计算并分析螺栓预紧力、螺栓数量与法兰厚度对最大累计损伤的影响.结果表明,所提出的方法和流程在塔筒螺栓疲劳强度分析与校核上具有可行性和有效性.

A general analytical formula of large deflection for annular throttle-slices in shock absorbers was deduced.The Chien-perturbation method was used to derive the stiffness curve equation of a single throttle-slice in shock absorbers.The analytical formula of large deflection for superposed throttle-slices was deduced directly and generalized.The undetermined coefficients of analytical formula were obtained through the finite element method（FEM） and curve fitting.Numerical results show that the analytical formula has satisfactory accuracy.

The fluid-structure interaction(FSI) modeling and solving techniques of shock absorbers are studied.The fluid field grid model of damper valve and the finite element contact model of superposition throttle-slices with higher accuracy are established based on FSI method with multi-solvers.The FSI model of shock absorbers is solved and analyzed combined by finite volume method(FVM) and finite element method(FEM).The speed characteristic and indicator diagram of shock absorbers are obtained.The internal pressure field and velocity field of damper valve are analyzed.The nonlinear dynamic characteristics of superposition throttle-slices are analyzed.The simulation results show that the pressure field of core region of damper valve changes rapidly because of the impact of high speed oil.The velocity of throttle-slices steps when the valve opens and closes.It makes the throttle channel change suddenly,and makes the indicator diagram bend down at the valve-opening point.The fluid field grid model of core region of damper valve and the finite element contact model of superposition throttle-slices have great influence to the accuracy of simulation.The FSI model is closed to the physical reality because of the consideration of turbulent flow of oil and the contact slip and large deflection of throttle-slices.The simulation results are in good agreement with the experimental results.