共查询到19条相似文献,搜索用时 125 毫秒
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前保险杠系统的轻量化可以减小能源消耗,降低成本,但须满足相关碰撞安全标准。在有限元软件HyperMesh中构建前保险杠系统模型,进行低速正面碰撞仿真验证模型的可靠性。定义变量、确定优化目标和约束条件后,创建Kriging代理模型,验证模型正确性。通过NSGA-II算法对代理模型优化求解,选取最优解,并根据仿真结果对最优解进行验证。结果表明:在保证碰撞性能要求的前提下,轻量化效果明显,验证了结构优化的可行性,为后续对保险杠系统的研究设计提供了参考。 相似文献
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以某款Plug-in混合动力电动汽车(Plug-in Hybrid Electric Vehicle,PHEV)的正面碰撞安全性为研究目标,针对设计结构和整车质量的变化可能导致原型车已经匹配好的乘员约束系统无法提供最优保护的情况,基于RBF神经网络算法,对PHEV的正面碰撞乘员约束系统的相关参数进行分析和优化,以降低假人头部、颈部和胸部的伤害值为目标,建立了PHEV的正面碰撞试验乘员约束系统仿真计算模型,通过仿真计算和实车正面碰撞试验,验证了优化后的乘员约束系统具有更好的被动安全性能。 相似文献
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以某乘用车前保险杠系统为研究对象,首先基于加拿大法规CFVSS215建立了正面碰撞和角度碰撞两种工况的保险杠低速碰撞有限元模型。其次从吸能、碰撞器加速度、碰撞器侵入量、横梁变形量和恢复系数几个方面对仿真结果进行分析,结果表明此保险杠在低速工况下具有较好的吸能作用,能很好地保护后部车体,但是恢复能力一般。最后提出改进方案,改进后的保险杠质量降低了21%,两种工况下的恢复系数分别增加了21.95%和96.88%,极大地提高了保险杠碰后恢复能力,而且还实现了轻量化目标。 相似文献
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汽车保险杠碰撞的有限元仿真与优化 总被引:1,自引:0,他引:1
本文以有限元法的系统动力学理论为基础,基于LS-DYNA有限元分析软件,对汽车保险杠与刚性墙的正面碰撞进行了模拟仿真计算,并对计算结果进行分析.以计算结果为依据,对保险杠的结构进行改进,优化其吸能能力.本次研究为保险杠的防撞设计开发提供了理论依据,对深入研究整车正面碰撞的模拟仿真具有重要的参考价值. 相似文献
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考虑汽车低速碰撞中的,使用复杂比例评价方法(COPRAS)对不同截面构型的汽车保险杠的耐撞性能进行综合评估与研究。首先,分别在对中碰撞和角度碰撞工况下,建立等质量的六种不同防撞梁截面构型的保险杠的有限元模型并进行仿真分析,选取碰撞加速度、碰撞时间、保险杠最大变形量和保险杠系统吸收能量为评价指标,然后,使用COPRAS评价方法对六种不同防撞梁截面构型的保险杠的综合耐撞性能进行评估,最后,得到具有最优综合耐撞性能的保险杠设计并进行耐撞性能分析。由此得出,COPRAS方法可以高效、合理地用于汽车保险杠的安全设计。 相似文献
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基于梯度的等效静载荷法的汽车正面碰撞关键结构优化设计 总被引:1,自引:0,他引:1
针对在已有车型的继承式开发中,由于结构尺寸、总布置等因素限制,无法快速准确地进行结构非线性优化设计的问题,提出了一种基于梯度的等效静载荷法与G1-G2设计规则以及载荷传递路径相结合的正面碰撞关键结构优化设计流程:收集对标车型数据,根据G1-G2设计规则,确定满足乘员损伤的最优目标加速度等效双阶梯形波;建立载荷数据库,得到一类车型的碰撞载荷路径百分比分布图;提取基础车型正面碰撞关键部件,以目标波形为指导对其进行必要的截面尺寸优化,并运用ESLMG对其进行厚度优化;将优化后的关键部件放入整车模型中,验证其加速度曲线是否达到目标值。结果表明,优化后的结构特性基本达到目标要求,整车碰撞性能得以改善。 相似文献
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以某款SUV车100%正面碰撞中的主要吸能部件保险杠为例,基于连续变截面薄板(TRB)技术,对保险杠结构进行设计优化,以期达到减少焊点、零件数量、生产工序,以及提高结构吸能能力的目的。研究结果表明:基于TRB技术设计的新型保险杠,刚度增加,在碰撞过程中吸收了更多的能量,降低了整车的变形和加速度峰值,整车的碰撞安全性能得到了改善。 相似文献
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运用 ANSYS/ LS-DYNA 软件对复合板应用于汽车保险杠进行了仿真模拟,根据保险杠低速碰撞试验规范-SAEJ2319,把不同厚度比的 PP/低碳钢复合板保险杠与单层的 PP 保险杠和单层低碳钢保险杠的碰撞性能进行对比,分析所得出的变形,加速度,碰撞应力应变,能量等特征参数后发现复合板的碰撞综合性能较好,其中厚度比为2:1的PP/低碳钢复合板碰撞综合性能最好。为 PP/低碳钢复合板运用于汽车保险杠的可能性提供了参考依据。 相似文献
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This paper presents a dynamically equivalent beam analysis model on pedestrian protection bumper impact instead of a non-linear
finite element impact analysis method. Equivalent beam analysis model was developed by substituting the femur and tibia for
dynamically equivalent Euler beam. Dynamically equivalent forces of bumper beam, upper stiffener and lower stiffener are found
by a finite element analysis results and applied to the Euler beam model of lower legform impactor. This equivalent beam analysis
model was used to obtain a bending angle of lower legform impactor by using finite element beam theory. Peak acceleration
of the tibia was obtained by developing an approximate acceleration equation. A linear interpolation of non-linear finite
element analysis results considering the dimension variation of bumper beam factors affecting the acceleration was used to
get an approximate acceleration equation. The accuracy of this simple analysis model was tested by comparing its results with
those of the non-linear finite element analysis. Tested bumper beam types were press type beam and roll forming beam used
widely in the current car bumpers. The differences of maximum acceleration of the tibia between the two models did not exceed
10% and the bending angle did not exceed 20%. This accuracy is enough to be used in the early stage of bumper beam design
to check the bumper pedestrian performance quickly. Use of equivalent beam analysis model is expected to reduce the analysis
time with respect to the non-linear finite element analysis significantly. 相似文献
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前纵梁是汽车发生正面碰撞时重要的能量吸收结构,对汽车碰撞安全和乘员保护具有重要作用。根据前纵梁结构特点,对其进行简化为薄壁梁结构,采用试验分析和模型仿真相结合的方法对矩形截面前纵梁的吸能特性进行对比分析;试验表明模型仿真结果的准确性。以仿真和试验分析结果的结论作为参考依据,选取影响前纵梁吸能特性的材料、厚度、截面形式、引导槽倾角等作为正交试验的4个因素,截面形式为6水平,其他因素为3水平,设计了L18正交试验表,将结构总质量、碰撞过程最大支反力作为约束,单位质量最大支反力作为目标进行不同截面前纵梁对比分析;分析结果可知:试验分析与建模仿真结果曲线的误差在10%以内,表明模型的准确与可靠性;前纵梁的截面形式为十字形、无设计倾角,材料则选择高强钢,厚度为1.6mm时,前纵梁的吸能性能最优,可以作为实际设计的参考。 相似文献
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Dong-Kyou Park 《Journal of Mechanical Science and Technology》2011,25(12):3107-3114
This paper presents a simple analysis model for bumper barrier impact and new IIHS (Insurance Institute for Highway Safety)
bumper impact instead of a non-linear finite element impact analysis. A dynamically equivalent beam approach was introduced
to simplify the non-linear dynamic bumper impact. For a bumper barrier impact, the equivalent curved-beam element was substituted
for the bumper beam and the bumper foam. For a new IIHS bumper impact, a modified curved-beam element of bumper barrier impact
considering the effect of contoured new IIHS impact barrier was used. The accuracy of this simple analysis model was tested
by comparing its results with those of the non-linear finite element analysis. Tested bumper beam types were press type beam
and roll forming beam used widely in the current car bumpers. The maximum displacement error between the two models did not
exceed 1.95% for a barrier impact and 13.2% for a new IIHS bumper impact. This accuracy is good enough to be used in the early
stage of bumper beam design process. This simple analysis model is expected to reduce the car development time and tests cost
significantly. 相似文献
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前纵梁抵抗弯曲变形的能力直接影响整车碰撞安全性。针对前纵梁进行引导结构优化设计,以提升抵抗弯曲变形能力。基于前纵梁弯曲变形工况,分析前纵梁弯曲变形的截面受力变形模式;外延变形具有最好的弯曲变形承载能力;设计具有外延变形和对称变形交替出现的前纵梁结构,选用开引导槽的结构形式进行优化设计;基于碰撞法规,选取正面100%刚性壁障碰撞和正面40%可变形壁障碰撞进行改变前后的性能验证;选取加速度、变形等指标进行对比分析。结果可知:外延变形承载能力最强,当外延变形和对称变形交替出现时,梁结构承载弯曲变形的能力最强;开设引导槽的间距需要满足外延变形波长和对称变形波长之和的整数倍;从两种碰撞工况前纵梁变形模式来看,改进设计使前纵梁的变形更为稳定,出现轴向稳定变形模式,同时提高了部分吸能特性,提高了整车的耐撞性;分析过程和结果为进一步实车验证提供重要参考。 相似文献
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陈臻 《江苏机械制造与自动化》2014,(1):148-149,156
在汽车保险杠原始结构的基础上,进行了轻量化设计.利用ANSYS/LS-DYNA软件对原始保险杠及其轻量化结构在低速碰撞过程中的动力响应特性进行了数值仿真,结果表明:原始保险杠在低速碰撞条件下应力分布不均匀,而加强筋保险杠和波浪加强板形保险杠耐撞性、能量吸收性更好,其应力分布较均匀,并且波浪加强板形保险杠性能优于加强筋保险杠. 相似文献
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Mechanical Properties Prediction of the Mechanical Clinching Joints Based on Genetic Algorithm and BP Neural Network 总被引:1,自引:0,他引:1
LONG Jiangqi LAN Fengchong CHEN Jiqing YU Ping 《机械工程学报(英文版)》2009,22(1):36-41
For optimal design of mechanical clinching steel-aluminum joints, the back propagation (BP) neural network is used to research the mapping relationship between joining technique parameters including sheet thickness, sheet hardness, joint bottom diameter etc., and mechanical properties of shearing and peeling in order to investigate joining technology between various material plates in the steel-aluminum hybrid structure car body. Genetic algorithm (GA) is adopted to optimize the back-propagation neural network connection weights. The training and validating samples are made by the BTM(R) Tog-L-Loc system with different technologic parameters. The training samples' parameters and the corresponding joints' mechanical properties are supplied to the artificial neural network (ANN) for training. The validating samples' experimental data is used for checking up the prediction outputs. The calculation results show that GA can improve the model's prediction precision and generalization ability of BP neural network. The comparative analysis between the experimental data and the prediction outputs shows that ANN prediction models after training can effectively predict the mechanical properties of mechanical clinching joints and prove the feasibility and reliability of the intelligent neural networks system when used in the mechanical properties prediction of mechanical clinching joints. The prediction results can be used for a reference in the design of mechanical clinching steel-aluminum joints. 相似文献