基于惯性释放原理的新能源车车架结构分析*
【摘要】为提高新能源车车架强度分析精度,在考虑了地面摩擦力与轮荷关系的前提下,基于多体动力学联合有限元分析方法建立了刚柔耦合整车数字样机及虚拟台架试验模型,对整车在多工况下的运动状态进行了模拟,并提取了各承载工况下车架连接点处的载荷。以所提取载荷作为车架边界载荷输入,利用惯性释放法对车架进行了强度分析,并根据分析结果对高应力区域结构进行优化设计及试验验证。结果表明,惯性释放法能有效避免边界条件对分析结果造成的影响,可得到较合理且符合实际的车架应力分布状态。
孙辉1 沈保山1 王新超1 陆永能2,3 员征文2,3
1. 221004;2. 221004; ( 徐州徐工汽车制造有限公司,徐州 徐工集团江苏徐州工程机械研究院,徐州3. 221004)徐工集团高端工程机械智能制造国家重点实验室,徐州
主题词:车架 多体动力学 惯性释放 结构优化U469.72 A 10.19620/j.cnki.1000-3703.20170069中图分类号: 文献标识码: DOI:
Structural Analysis of New Energy Vehicle Frame Based on Inertia Relief
Sun Hui1, Shen Baoshan1, Wang Xinchao1, Lu Yongneng2,3, Yun Zhengwen2,3 1. Xuzhou XCMG Automobile Manufacturing Co., Ltd, Xuzhou 221004; 2. Jiangsu Xuzhou Construction Machinery ( Research Institute, XCMG, Xuzhou 221004; 3. State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, XCMG, Xuzhou 221004) Abstract To improve the accuracy of structural strength analysis results of new energy vehicle frame, based on【 】simulation analysis of multi- body dynamics combined with finite element method, a rigid- flexible coupling digital vehicle prototype and a virtual bench test model were established, considering the relationship between friction forces of the ground and wheel loads, the motion state of the vehicle under multiple road conditions was simulated, and the loads at connection points of the frame under each load condition was extracted. Inertia relief method was applied to analyze frame strength using the load extracted above as frame boundary load input, the structure of the high- stress region was optimized and the simulation results were verified by experiments according to the results of the strength analysis. The experimental results show that using the inertial relief method can avoid the influence of boundary conditions on the finite element analysis results, rational and realistic frame stress distribution state can be obtained.
Key words: Vehicle frame, Multi-body dynamics, Inertia relief, Structure optimization
1 前言
车架作为整车的基体和主要承载部件,在实际工作过程中承受着复杂的外力作用[1],所以车架的强度和刚度在车辆总体设计中十分重要,而进行车架强度分析是车架结构设计改进的基础。传统的车架强度分析通常建立起轮胎与地面的连接关系,并在连接点处建立约束关系,但约束点反力及反力矩会严重改变结构实际受力状态[2- 3],造成应力结果奇异。为解决边界问题对分析 结果造成的影响,诸多学者对惯性释放在结构分析中的应用进行了研究[1- 5],但这些研究虽然在边界约束问题上取得了进步,但因未考虑部件间的非线性接触关系及地面对轮胎载荷的影响,使得分析计算精度较差。
为得到更精确的分析结果,本文基于惯性释放法联合多体动力学建立了整车刚柔耦合模型,在考虑了地面摩擦力与轮荷关系及车架与货箱等组件之间接触关系的前提下,对某新能源车车架进行了强度计算,并根据计算结果对车架高应力区域结构进行了优化,通过试验