考虑正面碰撞特性汽车前纵梁轻量化设计分析  

Lightweight Design and Analysis of Car-Body Front Longitudinal Based on Frontal Impact Characteristics

作　　者：崔华丽 李峰 于华[2] CUI Hua-li;LI Feng;YU Hua(Institute of Intelligent Manufacturing,Zhengzhou University of Economics and Business,He'nan Zhengzhou 450000,China;School of Material Science&Engineering,He'nan University of Science and Technology,He'nan Luoyang 471000,China)

机构地区：[1]郑州经贸学院智慧制造学院,河南郑州450000 [2]河南科技大学材料科学与工程学院,河南洛阳471000

出　　处：《机械设计与制造》2023年第8期158-161,共4页Machinery Design & Manufacture

基　　金：河南省高等学校青年骨干教师培养计划项目(2018GGJS212)。

摘　　要：前纵梁承载和吸收车辆正面碰撞的能量,保证安全性的前提下,可以通过厚度减薄实现轻量化。针对前纵梁的结构特点,采用强度等效减薄理论开展轻量化设计;在分析传统强度等效减薄公式的基础上,考虑材料变化后,相关的参数因素、残余应力、尺寸偏差和屈强比因素的影响,对公式进行修正;对某车型前纵梁开展优化设计,材料由DP590提升为DP780;对优化后的成形工艺进行分析;根据C-NACP正面碰撞要求,建立前纵梁总成碰撞分析模型,获取总吸能和承载力参数变化,并采用整车正面碰撞对比分析,以验证优化后零件的碰撞安全性。结果可知:根据修正公式,厚度由1.6mm减薄至1.4mm,实现轻量化减重12.5%;轻量化后,总成的能量吸收有较大提升;结构的最大承载力由346kN降低到322kN,降低了7.45%,表明整个过程的载荷呈现变缓的趋势,对于乘员保护是有利的;试验与模型分析结果对比,侵入量最大值分别为159.56mm和166.73mm,误差为4.5%,基本一致,表明结果的可靠性。分析结果表明修正强度等效减薄公式是有效的,为此类设计研究提供重要参考。The front longitudinal beam can bear and absorb the energy of vehicle frontal collision,and realize lightweight through thickness reduction on the premise of ensuring safety.According to the structural characteristics of the front longitudinal beam,the strength equivalent thinning theory was used to carry out the lightweight design.Based on the analysis of the traditional strength equivalent thinning formula,considering the influence of the relevant parameters,residual stress,size deviation and yield ratio afier the change of material,the traditional strength formula was modified.The optimization design of the front longitudinal beam of a certain vehicle was carried out,and the material was upgraded from DP590 to DP780.The forming process after optimization was analyzed.According to the requirements of C-NACP frontal collision,the front longitudinal beam assembly collision analysis model was established,and the total energy absorption and bearing capacity parameters were obtained to verify the collision safety of the optimized parts.The results show that:according to the modified formula,the thickness is reduced from 1.6mm to 1.4mm,achieving lightweight weight reduction of 12.5%.After lightweight,the energy absorption of the assembly is greatly improved.The maximum bearing capacity of the structure is reduced from 346kN to 322kN,reducing by 7.45%,indicating that the load in the whole process is slowing down,which is beneficial to occupant protection.Compared with the results of model analysis,the maximum intrusion volume is 159.56mm and 166.73mm respectively,and the error is 4.5%,which is basically consistent,indicating the reliability of the results.The analysis results show that the modified strength equivalent thinning formula is effective,which provides an important reference for such design and research.

关 键 词：白车身 前纵梁 正面碰撞 强度等效 安全性 模型 试验 

分 类 号：TH16[机械工程—机械制造及自动化] U464.138.2[机械工程—车辆工程]