综合经典力学与有限元的汽车二维碰撞事故车速再现方法研究

Velocity Reconstruction Method for Vehicle Two-Dimensional Collision Accident based on Classical Mechanics and Finite Element

为了揭示汽车碰撞事故中速度与能量的变化规律,为事故再现与责任划分提供根据,研究车辆碰撞事故的速度再现方法.梳理现有事故,再现经典力学与有限元分析方法,在此基础上提出了综合经典力学与有限元的汽车二维碰撞事故车速再现方法.首先基于经典力学动量公式,计算车辆碰撞接触速度参数;再以该参数为初始值进行有限元碰撞仿真实验;通过不断调整该参数使得碰撞仿真变形与实际变形相符并输出能量值;最后借助经典力学动量、能量及弹性恢复系数关系,验证速度参数.结合一起实际事故案例,验证该方法的有效性.研究表明:分别与PC-Crash及有限元分析结果相比,综合法所得的速度与能量误差均在5%以内;该方法既充分利用了车辆变形信息又在初始碰撞速度相对明确条件下进行有限范围试算,改善事故再现结果可信度的同时提升了再现分析效率.

In order to reveal the variation law of velocity and energy in automobile collision and provide theoretical basis for accident reconstruction and liability division,the velocity reconstruction method of vehicle in two-dimensional collision accidents is studied.On the basis of reviewing the existing classical mechanics and finite element analysis methods for accident reconstruction,the classical mechanics and finite element method for vehicle velocity reconstruction of two-dimensional collision accident is proposed.Firstly,based on the momentum formula,the instantaneous velocity parameters of vehicle collision contact are calculated.Then the finite element collision simulation experiment is carried out with the parameter as the initial parameter.By adjusting the parameters continuously,the collision simulation deformation is consistent with the actual deformation and the energy value is output.Finally,the velocity parameters are verified by the relationship of momentum,energy and elastic recovery coefficient in classical mechanics.An actual accident case is reconstructed and analyzed.Through the comparison of the results,the effectiveness of the method is verified.The results show that,compared with PC-Crash and finite element simulation results,the velocity and energy errors obtained by the combination method are both within 5%.The combination method not only makes full use of vehicle deformation information,but also carries out the finite range trial calculation under the condition that the initial collision velocity is relatively clear,which improves the reliability of the accident reconstruction results and enhances the reconstruction analysis efficiency.