某蓄电池支架开裂分析和优化

针对某车型蓄电池支架在路试过程中出现开裂的问题,利用有限元法对支架总成进行强度和模态分析,对开裂原因进行排查。分析结果表明支架总成1阶模态固有频率过低,且开裂位置存在较大的应变能集中,导致支架总成发生共振开裂。根据分析结果对蓄电池支架总成进行优化,其1阶模态固有频率明显提升,开裂处应变能集中情况显著改善。路试证明支架未再次发生开裂,优化后的支架总成满足车型开发要求。     

泵车底盘副水箱安装支架有限元分析与结构改进

某工程车在可靠性道路试验发动机怠速过程中由于副水箱抖动厉害而出现开裂的现象。本文运用Pro/ENGINEER软件建立副水箱及安装支架的三维模型,运用有限元仿真平台ANSYS Workbench对副水箱安装支架进行强度失效原因分析,并根据分析结果改进安装支架结构形式,经试验验证了结构与方法的正确性。     

某车型发动机悬置后支架优化设计和疲劳分析

针对某车型发动机在振动强化试验中悬置后支架出现开裂的问题,建立悬置后支架有限元模型并进行应力分析,发现应力分析结果与试验结果一致,且原支架结构应力集中现象非常明显,主要分布在侧筋根部;用OptiStruct对悬置后支架进行拓扑优化设计,结果表明拓扑优化材料应主要布置在底部和侧筋.在此基础上,通过4种优化方案的对比得到质...     

基于MSC Nastran的汽车ESP安装支架优化与设计

为提升汽车ESP安装支架的动力学性能,利用MSC Nastran对其进行强迫运动分析.分析支架系统的共振频率和加速度的最大增益特性,并根据分析结果对原始模型进行优化设计,提升ESP支架性能,从而保证车辆在各种状况下行驶的稳定性及安全性.使用仿真和台架试验的方法验证优化后的支架性能,二者结果非常接近,表明该仿真方法可为ESP支架的优化设计提供参考.     

基于LS-DYNA的汽车保险杠碰撞仿真研究

以显式动态有限元理论为基础,对汽车保险杠的碰撞进行了计算机仿真研究.作者根据台车碰撞试验对汽车吸能装置的要求及设计的汽车保险杠的结构尺寸,用Pro/ENGINEER建立了碰撞体及保险杠的仿真模型,用ANSYS对模型作了前处理,调用LS-NYNA 求解器ls970进行了求解,最后用LS-PREPOSTD作了后处理,并对仿真结果进行了分析.通过仿真可预测出汽车保险杠发生碰撞时受力、变形和吸能情况,从而为保险杠的优化设计提供了依据.     

汽车前保险杠缓冲吸能结构低速碰撞仿真分析

在低速碰撞中对某车型的汽车保险杠进行仿真分析,对保险杠模型进行简化,利用HyperMesh建立有限元模型,再提交给LS-DYNA进行计算,使用HyperView对碰撞结果进行处理得到相关响应参数,并对响应参数进行结果分析,进而确定在汽车保险杠发生低速碰撞时其最主要吸能的部件以及吸能部位的响应特性,为保险杠设计提供理论基础。     

面向汽车转向系统NVH性能的分析与设计流程

提出一种面向汽车转向系统NVH性能的分析与设计流程,简述转向系统振动的激励源,针对转向柱总成进行模态分析与试验对比,并结合提升转向柱与仪表板安装横梁总成NVH性能的工程实例,进一步针对转向柱安装支架进行静强度分析与结构优化,该方法在奇瑞某车型开发中得到较好的应用.     

维修电工电气管道安装工程常见问题及对策

由于受到技术水平、制度、人员等因素的制约,维修电工电气管道安装中存在问题,常见问题主要体现在没有执行规范标准,安装质量控制不严,管道支架、系统噪音存在问题.为应对这些问题,提高安装质量,需要采取相应对策,执行维修电工电气管道安装规范标准、加强安装质量控制、提高管道支架安装质量、减缓管道安装噪音,并提高维修电工安装人员素质.     

基于Revit的支架族开发与应用

支架的安装是基于建筑物的空调、给排水、强弱电等系统,由于涉及系统多、各系统管线复杂、设计图纸信息不 充分,以及支架的安装对建筑物的主体结构依赖性强,后续安装时增加安装难度,浪费安装空间。利用BIM 技术进行有效综 合与深化设计,预先对机电系统进行模拟安装,解决施工难点,节约管线与支架材料,增加建筑净高,对综合管线进行碰撞检 测。实现可视化的协同设计变更,有利于各专业进一步的深化设计,简化施工程序,更有利于施工现场的管理与缩短工期,从 而节省成本。本文运用BIM 技术,对支架的安装,设计以及施工的综合优化,可视化模拟进行了说明。     

基于行人下肢防护的前保险杠改进分析

利用有限元方法,建立了小腿冲击器与汽车前部结构的碰撞模型,用以评价某款车保险杠系统对小腿损伤的影响。通过增加吸能部件、副保险杠加强板等方式减轻行人下肢的损伤,并通过正交试验设计研究了吸能部件的材料、吸能部件前后面之间的距离、副保险杠加强板的厚度以及副保险杠加强板前后面之间的距离对行人下肢损伤的影响。研究结果表明,经正交试验设计后的前保险杠系统能有效地减小小腿冲击器的胫骨加速度以及膝关节弯曲角度,使得下肢保护指标满足Eu-roNCAP法规要求。优化设计后的前保险杠系统更好的防护行人下肢的损伤。     

Evaluation of a knee-kicker bumper design for reducing knee morbidity among carpet layers

Carpet layers have a high prevalence of occupational knee morbidity. One of the main causes is that they need to frequently 'kick' the bumper on the rear end of the knee kicker with one knee when laying a carpet. Considering the bumper's marked effects on kicking force transmission and safety, this study aims to improve the design of the knee-kicker bumper by reducing the risk factors. An improved pendulum-type impact-testing platform was designed as an evaluative apparatus, with the impulse and the coefficient of restitution serving as evaluative criteria. The newly developed bumper has improved firmness from drilled blind holes and an increase in effective forward force of 15%-138%, which implies lower operational demands and a lighter knee burden (i.e., less kicking energy results in the same work efficiency), and a softer contact surface that enhances operating comfort. The newly designed kicker was positively reviewed by subjects.     

Crash simulation of bumpers

In the United States, Federal regulation FMVSS 215 (General guide for substantiation of compliance with FMVSS 214 and 215 CFR 581: Bumper Standard, pp. 9–81) requires that impact data of the front and rear bumpers of cars be furnished for each make of vehicle. In this paper, the crash data of two bumper beams are analyzed by simulated computer models using the ABAQUS (Hibbitt, Karlsson and Sorensen, Inc., Providence, RI, Version 4-5-17IB) program. The salient feature of the automatic time incrementation scheme is used. Inelastic large deformation is considered. Although sectional properties of the two beams and the initial impact condition are the same, the technique used in selecting convergence tolerance is quite different due to the differences in configuration. With due consideration good convergence can be achieved in less than 100 time increments. Economically this compares very favorably to the actual testing during the initial development process. The merits of crash simulation study are twofold: (i) providing economical evaluation of bumper capability; and (ii) serving to establish methods for comparing one bumper to another for initial development purposes.     

基于MSC Nastran的后视镜模态频率优化

为解决试验车搓板路试验中外后视镜垂向抖动问题,建立外后视镜有限模型,对该有限元模型与实物动力学一致性进行验证,证实有限元模型可用,将后视镜有限元模型装配在车门进行模态分析,找到垂向抖动原因,采用应变能法识别出设计弱点,对弱点进行优化,最终解决后视镜抖动问题.     

Crashworthiness design for functionally graded foam-filled bumper beam

Automotive bumper beam is an important component to protect passenger and vehicle from injury and damage induced by severe collapse. Recent studies showed that foam-filled structures have significant advantages in light weight and high energy absorption. In this paper, a novel bumper beam filled with functionally graded foam (FGF) is considered here to explore its crashworthiness. To validate the FGF bumper beam model, the experiments at both component and full vehicle levels are conducted. Parametric study shows that gradient exponential parameter m that controls the variation of foam density has significant effect on bumper beam’s crashworthiness; and the crashworthiness of FGF-filled bumper beam is found much better than that of uniform foam (UF) filled and hollow bumper beam. The multiobjective optimization of FGF-filled bumper beam is also performed by considering specific energy absorption (SEA) and peak impact force as the design objectives, and the wall thickness t, foam densities ρ_f1 and ρ_f2 (foam densities at the end and at mid cross section, respectively) and gradient exponential parameter m as design variables. The Kriging surrogate modeling technique and multiobjective particle swarm optimization (MOPSO) algorithm were implemented to optimize the FGF-filled bumper beam. The optimized FGF-filled bumper beam is of great advantages and it can avoid the harmful local bending behavior and absorb more energy than UF filled and hollow bumper beam. Finally, the optimized FGF-filled bumper beam is installed to a passenger car model, and the results demonstrate that the FGF-filled bumper beam ensures the crashworthiness performance of the passenger car while reduces weight about 14.4% compared with baseline bumper beam.     

视觉引导的搬运机器手位置测量研究

为提高工作效率,满足搬运机器手自动化抓取汽车保险杠的需要,研究了基于结构光视觉原理的保险杠抓取点位置测量方法。该方法通过对相机拍摄图像进行图像处理,识别出投射在保险杠平坦区域的激光光斑中心点;利用透视变换原理对获取的激光光斑图像进行矫正,最后结合像素标定结果计算得到汽车保险杠抓取点沿图像X轴方向偏移量和高度信息。现场实验结果表明：该测量方法稳定性能好,测量误差小于±3mm,可以实现对汽车保险杠的非接触测量,实时引导搬运机械手准确抓取汽车保险杠,给自动化行业提供一种简单准确的定位识别系统和方法。     

基于行人保护FLEX-PLI腿型的车辆前结构改进分析

欧盟新车评价规程Euro NCAP中的TRL腿型验算即将被FLEX-PLI腿型验算替代，所以针对前者开发的某款车型在使用新标准验算时不能得到满分。运用计算机仿真对该车型前端结构进行改进：去除前保险杠吸能泡沫；重新设计W形结构的下腿部保护横梁，在碰撞点对应位置增加与FLEX-PLI腿型宽度相同的加强筋，加大下腿部保护横梁与前保横梁的距离；改进导风板局部结构。对改进后前端结构进行FLEX-PLI腿型验算，达到得分为满分的目标。     

循环队列中的头尾指针设计

本文研究了一种基本的数据结构--循环队列,讨论了循环队列的四种头尾指针的设置方法对入队、出队算法实现的影响,说明要写出简单出入队算法的关键在于头尾指针初值的设置,总结了四种头尾指针约定下合理的初值设置和出入队算法.