综合经典力学与有限元的汽车三维碰撞事故再现分析方法

Once vehicle collision accident occurs, it cannot be replayed veritably. Because of this irreversible characteristic, it is difficult to determine some factors such as travelling speed or travelling direction before collision accurately after accidents occur. Furthermore, the description of the accident plot provided by accident parties may be different even contradictory from each other. Thus, it is difficult to distinguish accident responsibility. Combining the classical mechanics with the finite element method to analyze this theme, there will be a theoretical significance on several aspects, such as improving the level of accident reconstruction, distinguishing accident responsibility and reducing accident disputes. The calculation results of classical mechanics can provide the initial kinetic parameters to finite element collision simulation. The finite element analysis method can realize microscopic simulation of the process of collision and deformation. In addition, by comparing simulate deformation with actual deformation, the validity of accident reconstruction can be verified. Based on the theory of classical mechanics, collision dynamics model and rolling trajectory model of automobile three-dimension collision accident will be constructed. According to finite element simulation experiments of automobile collision, automobile's collision velocity, deformation, Von strain and kinetic energy will be analyzed, by finite element analysis method. The synthetical method of classical mechanics and finite element for accident reconstruction will be proposed. According to accident cases, the model and method can be tested and verified. The project applicant has long been engaged in accident reconstruction analysis. With these work experience and research foundation, the project applicant has ample research reserve of this project in aspects of model constructing, finite element collision simulation and case analysis.

汽车碰撞事故一旦发生，便不可能真实重演。该不可逆特性使得事故发生后，诸如碰撞前行驶速度或行驶方向等因素难以准确确定，甚至出现当事人对事故情节各执一词的情况,给事故责任认定带来不便。综合经典力学理论与有限元分析方法开展本研究，在提高事故再现分析水平，明确事故责任，缓解事故纠纷等方面意义重大。经典力学模型的计算结果能为有限元碰撞仿真提供初始动力学参数；而有限元分析能对碰撞及变形过程进行微观仿真，且仿真变形与实际变形的对比还有利于验证事故再现的有效性。本项目拟基于经典力学理论，构建汽车三维碰撞事故的碰撞动力学模型及翻滚轨迹模型；利用有限元分析方法，进行汽车碰撞仿真实验并分析碰撞速度、变形、应力及动能等因素；提出碰撞事故再现的经典力学与有限元结合法；依据事故案例进行模型方法验证。申请人具有长期从事事故再现分析的工作经验与扎实的研究基础，在模型构建、有限元碰撞仿真及案例分析方面，具有充分的研究储备。

汽车三维碰撞事故是较为复杂的事故形态。长期以来，对于该类碰撞事故的再现分析理论与方法尚不完善。现有研究大多基于单一理论体系进行再现分析，如经典力学原理或有限元分析方法，各自均存在一定的应用局限性。因此，有必要将经典力学与有限元相结合，研究提出一套综合再现分析方法以克服各自的局限性。.本项目针对汽车三维碰撞事故，基于经典力学原理，研究构建了该类事故的三维碰撞运动参数动力学计算模型，构建了描述汽车三维翻滚运动轨迹的四棱柱翻滚模型与六棱柱翻滚模型。基于有限元分析方法与ANSYS软件，通过构建汽车有限元模型并进行碰撞仿真实验，对碰撞速度、能量、变形及应力分布进行分析，总结提出了面向汽车碰撞事故再现分析的经典力学与有限元结合法。通过事故案例再现分析与结果对比，验证了模型与方法的有效性。.研究提出的经典力学与有限元结合法，使得原本单纯基于经典力学模型无法获得的碰撞变形、能量损失、应力分布及碰撞过程速度变化等重要信息得以再现；使得原本单纯基于有限元方法碰撞初始速度获取困难、轨迹再现难以实现等局限性得以弥补。研究构建的汽车三维碰撞动力学参数计算模型，实现了碰撞接触瞬间与分离瞬间竖向速度、纵倾角速度、侧翻角速度的互逆运算。构建的汽车三维翻滚运动的四棱柱翻滚轨迹模型与六棱柱翻滚轨迹模型，实现了汽车三维翻滚运动过程中，任一时刻车辆空间位置及姿态的计算与翻滚过程汽车轨迹的再现。.项目研究成果在再现分析事故发生过程、揭示碰撞变形形成机理及能量转化规律等方面具有重要的理论借鉴意义；在交通事故处理及责任认定等交通安全管理方面具有重要的实际应用价值与推广应用前景。