碰撞工况下列车爬车机理与控制方法

Since the train collision accidents are usually unpredictable, it is difficult to obtain the collision boundary conditions, which brings a lot of trouble for the train collision simulation. Under this background, different numerical simulation methods are adopted in this project. The approximation expression between the collision boundary conditions and the train overriding degree is proposed according to the large-scale simulations. Therefore, with the help of this approximation expression, the collision boundary conditions can be calculated from the train overriding degree. Besides that, from the simulation results, the main influence factors on the train overriding degree are pointed out. The vehicle pitching movement and the interactive relationship between the vehicle system dynamics and structural crashworthiness are also fully studied. Moreover, the vertical buckling mechanism of the anti-climber is analyzed and its structure is optimized according to the multi-objective optimization. The researches in this project can reduce the risk of vehicle overriding during a train collision and promote the development of the passive safety of rail vehicles.

由于列车碰撞事故通常不可预知，碰撞发生时的边界条件难以全面获取，给碰撞事故调查以及过程再现分析带来了极大的困扰。为此，本项目融合现有数值计算方法，针对列车碰撞的潜在边界条件开展大范围碰撞仿真计算，构建碰撞边界条件与列车爬车程度之间的近似代理模型，从而根据碰撞事故发生后的爬车程度结合现场调查反演列车碰撞时的主要边界条件，再现列车碰撞爬车的动态过程。通过模拟列车不同程度的爬车运动，揭示诱发列车碰撞爬车的主要影响因素，分析纵向碰撞力引发的车辆点头运动对爬车程度的影响，阐明碰撞过程中车辆整体运动状态与局部结构压溃变形的相互作用关系，进而揭示防爬器垂向屈曲失效的机理以及失效后车体底架强刚度区域与相邻车辆上部弱刚度区域碰撞、加剧车辆爬车的发展过程。在防爬器结构优化设计的基础上，提出列车吸能结构基于耐碰撞性与稳定性的协同优化设计理念，为控制列车碰撞爬车程度、减少人员伤亡提供有效途径，具有重要科学意义。

由于列车碰撞事故通常不可预知，碰撞发生时的边界条件难以全面获取，给碰撞事故调查以及过程再现分析带来了极大的困扰。为此，本项目融合了现有数值计算方法，建立了多刚体列车碰撞模型和有限元列车碰撞模型，基于列车碰撞的潜在边界条件开展了大范围碰撞仿真计算，再现了列车碰撞爬车的动态过程。通过模拟列车不同程度的爬车运动，揭示了诱发列车碰撞爬车的主要影响因素，包括列车碰撞速度、碰撞列车之间的差异性、车钩缓冲器的失稳、吸能式防爬器的垂向弯曲等。此外，分析了纵向碰撞力引发的车辆点头运动对爬车程度的影响，阐明了碰撞过程中车辆整体运动状态与局部结构压溃变形的相互作用关系，进而揭示了防爬器的垂向弯曲失效以及失效后车体底架强刚度区域与相邻车辆上部弱刚度区域碰撞、加剧车辆爬车的发展过程。在此基础上，从压溃顺序、几何截面、芳纶蜂窝填充、结构参数优化等多角度对现有吸能器开展了多目标优化设计，大幅度提升了吸能器的耐碰撞性能。本项目的研究为控制列车碰撞爬车程度、减少人员伤亡提供了有效途径，具有重要科学意义和工程价值。