基于高强度钢成形的车身轻量化研究
发布时间：2019-05-15 02:15
【摘要】：伴随着人类社会的快速发展,汽车也承担起了越来越多的社会责任,节能、排放、安全相关的法规越来越严格,轻量化技术是满足上述三个法规的有效方法,采用高强度钢板不仅可以达到轻量化而且能满足碰撞安全性。本文主要以高强度钢板为研究对象,主要工作如下:1)以典型热成形零件B柱加强板为例,采用数值模拟的方法对热成形过程进行了研究。通过热-力相变-耦合概述了成形时温度场分布和应力场分布规律;同时以成形结束后温度场的分布是否符合马氏体的转变温度,来判断热成形模拟的可靠性。成形结束后的零件抗拉强度为1456MPa,硬度为479HV,总结了板料初始加热温度、冲压速度对成形结束后温度场和应力场分布的影响,得出了本次B柱加强板热成形模拟的工艺参数组合:初始加热温度850℃、冲压速度200mm/s。2)以高强度钢板成形为例,研究成形历史对碰撞仿真精度的影响。以某汽车纵梁内板为研究对象,通过利用试验设计方法和遗传算法对成形工艺参数进行优化求解,通过利用result mapper工具将成形模拟结果映射到碰撞模型中。以碰撞力和吸能值为评价指标,分析成形后零件的厚度分布、塑性应变分布对碰撞仿真仿真精度的影响。结果表明:考虑冲压成形历史与不考虑成形历史的吸能误差达到11.7%。3)以热冲压件为例,研究热冲压件在耐撞性方面的应用。以不同材料组合的纵梁结构为研究对象,通过对比碰撞后的碰撞力峰值和吸能值,表明在碰撞力峰值增加幅度不大的情况下,其吸能值增加47.8%,相比传统的通过利用诱导槽来增加吸能效果相比,具有明显的优势。以B柱为研究对象,通过简化侧面碰撞模型,引入与整车类似的边界条件,提高模型的可靠性,通过减少热成形B柱的厚度,与原模型进行对比分析,结果表明在侧碰工况下,侵入量和侵入速度都有改善,同时质量减少0.92kg。
[Abstract]:With the rapid development of human society, cars have also assumed more and more social responsibilities, energy saving, emissions, safety related laws and regulations are becoming more and more strict, lightweight technology is an effective way to meet the above three laws and regulations. The use of high strength steel plate can not only achieve lightweight but also meet the collision safety. In this paper, the high strength steel plate is taken as the research object, the main work is as follows: 1) taking the typical hot forming part B column reinforced plate as an example, the hot forming process is studied by numerical simulation. The distribution of temperature field and stress field during forming is summarized by thermal-mechanical phase transformation-coupling, and the reliability of thermal forming simulation is judged by whether the distribution of temperature field after forming is in accordance with the transformation temperature of martensite. The tensile strength and hardness of the parts after forming are 1456 MPA and 479HV. the effects of initial heating temperature and stamping speed on the distribution of temperature field and stress field after forming are summarized. The process parameter combination of hot forming simulation of B column reinforced sheet is obtained: initial heating temperature 850 鈩，
本文编号：2477239
[Abstract]:With the rapid development of human society, cars have also assumed more and more social responsibilities, energy saving, emissions, safety related laws and regulations are becoming more and more strict, lightweight technology is an effective way to meet the above three laws and regulations. The use of high strength steel plate can not only achieve lightweight but also meet the collision safety. In this paper, the high strength steel plate is taken as the research object, the main work is as follows: 1) taking the typical hot forming part B column reinforced plate as an example, the hot forming process is studied by numerical simulation. The distribution of temperature field and stress field during forming is summarized by thermal-mechanical phase transformation-coupling, and the reliability of thermal forming simulation is judged by whether the distribution of temperature field after forming is in accordance with the transformation temperature of martensite. The tensile strength and hardness of the parts after forming are 1456 MPA and 479HV. the effects of initial heating temperature and stamping speed on the distribution of temperature field and stress field after forming are summarized. The process parameter combination of hot forming simulation of B column reinforced sheet is obtained: initial heating temperature 850 鈩，
本文编号：2477239
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