基于可靠性优化设计的乘用车侧面碰撞安全性研究

The passenger vehicle side impact is a kind of traffic accidents with high frequency. However, the existing side impact regulations are based on collision test under certain conditions; it can not fully measure the safety performance of vehicle side impact. Thus, the focus of this project is on improving the reliability of the passenger vehicle’s side collision resistant performance. The research makes full use of finite element simulation and real vehicle test method. It is proposed to achieve some breakthroughs on the following technologies; they are the extracting techniques of the main features of deformation area, the reliability optimization design of passenger vehicle side impact and the evaluation system of vehicle side impact. The project will take full use of the statistics database of actual traffic accidents investigated in Changsha City. The probability of side impact location is considered as random variables. The characteristic parameters extracted from the deformation area are treated as design variables. The injury value of the side impact passenger is considered as the evaluation indicator. Then, a large number of finite element simulation combined with optimization design method is conducted to get the best parameter values that meet the reliability requirements. The mutual integration of finite element simulation and reliability optimum design is to be realized. Finally, the project will form a comprehensive system that measures the passenger vehicle’s safety performance during side impact, and it will promote the development of automotive safety technology.

乘用车侧面碰撞是发生频率最高的交通事故之一，而现有的碰撞法规都是在某些特定条件下进行碰撞试验的，它并不能全面衡量车辆的侧面碰撞安全性能。本项目围绕乘用车侧面碰撞安全的可靠性展开研究。采用有限元仿真模拟和实车试验相结合的方法，拟在已有研究成果的基础上重点实现以下技术突破：1）乘用车侧面碰撞变形区域主要特征提取技术研究；2）乘用车侧面碰撞可靠性优化设计研究；3）乘用车侧面碰撞评价体系研究。项目以“长沙市深入调查交通事故数据库”为基础，研究乘用车侧面碰撞各情况出现的概率，以侧碰变形区域提取的特征参数作为设计变量，以侧碰过程中乘员的损伤值作为评价指标，进行大量的有限元仿真模拟并结合优化设计方法，从而得到满足可靠性要求的最佳参数值，实现侧碰有限元仿真与可靠性优化设计的相互集成，最终形成一套能全面衡量乘用车侧面碰撞安全性能的系统，促进汽车安全技术的发展。

乘用车侧面碰撞是造成人员伤亡最多的交通事故形态之一。现有的汽车碰撞安全法规都存在一定的局限性，不能全面评价车辆侧面碰撞的安全性能。项目通过有限元仿真分析与实验相结合的方法，研究薄壁梁结构参数的对其吸能特性的影响规律，并通过台车试验对典型薄壁梁的吸能特性进行验证。在乘用车侧面碰撞事故调查的基础上，将可靠性理论应用于乘用车侧面碰撞安全性研究，对车身侧围关键部件的相关参数进行可靠性优化设计，研究表明在乘用车侧面碰撞过程中可靠性优化设计使得质量减少的同时使得吸能量增大，且各输出响应值都远离约束边界，优化结果达到可靠性要求。项目提出在驾驶员侧前车门内板处增加防护衬垫和在驾驶员侧A、B柱之间的车顶纵梁处增加头部安全气囊两种防护措施，并建立了相应的有限元模型。将头部安全气囊和防护衬垫有限元模型一起集成到侧面碰撞乘员损伤模型中进行碰撞分析，研究表明侧面碰撞乘员头部损伤指标HIC值、胸部肋骨压缩变形量RDC、胸部粘性指标VC和骨盆损伤指标CAIF都降至最低限定值以下，从理论上证明了所提措施的有效性，同时将乘员的综合伤害评估值WIC降低了17.137%，有效的降低了乘员综合损伤，提高了乘用车侧面碰撞安全性。该项目提出的乘用车侧面碰撞可靠性优化设计方法及乘员防护措施可用于汽车企业的技术革新，并可为我国制定更加合理的汽车碰撞安全标准提供参考。