【作者】 高祥；

【导师】 张乐乐；

【作者基本信息】 北京交通大学 ， 安全技术及工程， 2008， 硕士

【摘要】 高速运行的列车一旦发生碰撞事故,将会导致车体的破坏,从而引起乘客的伤亡和极大的财产损失,因此高速列车的被动安全性研究受到各国的重视。随着计算机技术的发展以及显式有限元技术的成熟,采用计算机数值方法进行高速碰撞仿真,研究高速列车大变形碰撞特性,进而对车辆结构碰撞特性进行优化,提高列车的被动安全防护技术有着非常现实而重要的意义。本文主要利用有限元分析软件ANSYS/LS-DYNA针对几种典型的列车碰撞情景进行了仿真与分析,并对乘客在碰撞时的响应,进行了简单情景下的二次碰撞仿真与分析。首先,对200km/h铝合金列车车体进行了三维实体建模并使用Hyper Mesh软件进行了网格划分,通过对单元类型,材料模型、接触搜索算法的选择以及载荷的施加建立了车体的有限元模型。其次,对单节车厢与固定刚性墙、可移动刚性墙进行了碰撞仿真。仿真结果分析表明,碰撞时间极短,变形集中在车体前部,车体主体的客室部分几乎不发生变形;碰撞过程中的绝大部分动能被车体前部的一小部分结构所吸收:车体前端加速度最大,从车体前端到后端,其加速度逐渐减小;针对碰撞后的爬车现象可能性进行了分析。另外,通过列车在不同条件下的碰撞仿真,分析了不同初速度,不同材料参数对碰撞结果的影响,发现碰撞速度越大车体塑性变形越剧烈,车体破坏越严重;材料的杨氏模量越大,车体碰撞时的塑性变形越小。最后,利用标准假人模型在简单场景设置条件下进行二次碰撞仿真计算,并根据有关伤害指标分析比较了假人模型头部、胸部可能的伤害程度。更多还原

【Abstract】 The crash accident of train brought great damage to vehicles and property. Seriously, some passengers will be injured and lost their life in accident. So the passive safety of high-speed passenger vehicles is important and should be highly considered. With the development of computer technology and explicit finite element method, it is possible the numerical simulation of high-speed crash will be come true. The researches which are about the crash characteristics of high-speed crash with the large deformation will be practical and useful to improve the passive safety of high-speed passenger vehicles.Based on ANSYS/LS-DYNA, several classical crash processes of vehicles and the response of passengers with the second-crash have been simulated and analyzed.Firstly, according to the design drawing, the three-dimensional model of 200km/h aluminum alloy bodyshell has been set up with the software ANSYS and then it was meshed with the software Hyper Mesh. According to the selection of element types, material model and contact types and load, the finite element model has been finished.Secondly, the frontal crash on single vehicle with fixed rigid and movable rigid wall have been studied. The simulation data indicated that crash time was very short, very large plastic deformation had been produced in the head of bodyshell, little deformation had been produced in the middle, the kinetic energy was mainly absorbed by a few structures, the crash acceleration got max value at the crash location and became smaller from the front to the end of the vehicle, and the possibility of climbing has been analyzed.Furthermore, according to the simulation of different crash conditions, the result of vehicle crash had been analyzed under different initial velocities and material parameters. The conclusion shows that the more initial speed, the larger plastic deformation and the more EX, the less plastic deformation.In the end, the second-crash had been simulated by using the Hybrid III 95% dummy. Damage degree of the head and chest of the dummy has been analyzed and compared with the relative damage index.更多还原