汽车碰撞速度分布分析及加速度峰值数字特征计算

Analysis of Vehicle Impact Velocity Distribution and Calculation of Acceleration Peak’s Numerical Characteristics

为给随机碰撞条件下汽车安全系统的优化提供统计学意义上的数据支持,对汽车碰撞时的速度分布和加速度峰值进行研究。先对美国国家公路交通管理局中的碰撞事故数据进行统计,基于统计学分析,借助统计软件SPSS得出碰撞速度概率密度函数;再通过LS-DYNA建立台车碰撞仿真模型,根据碰撞仿真计算的结果来建立碰撞车速与加速度峰值的回归方程;然后利用碰撞速度概率密度函数计算出加速度峰值的数字特征。结果表明:碰撞车速近似符合正态分布,车辆在车速为48.48km/h时发生碰撞的概率最大;利用台车碰撞仿真模型可以复现任意碰撞车速的加速度曲线,解决以往研究中加速度曲线单一的问题,而加速度峰值的数字特征可直接用于优化汽车安全设计中。

In order to provide the statistical data that can be used to improve the automobile safety design under the condition of random collision,the research and analysis of the vehicle impact velocity distribution and the acceleration peak were carried out in this paper.Based on the statistical data from the US National Highway Safety Administration,the probability density function of vehicle impact velocity was obtained by the statistical software SPSS.Then,the finite element model of trolley collision test system was built in LS-DYNA.The regression equation about impact velocity and acceleration peak is obtained with the analysis of simulation results.Finally,the numerical characteristics of acceleration peak are calculated by using the probability density function of vehicle impact velocity already obtained.The results show that the vehicle impact velocity is almost subject to normal distributing and there is the biggest possibility of a crash occurring when the vehicle speed is close to 48.48 km/h.The problem that the acceleration curve is single in the previous researches is solved because the acceleration curve at arbitrary initial velocity is obtained on the finite element model of trolley collision test system.The numerical characteristics of acceleration peak are directly used to improve the automobile safety design.