小型客车碰撞特性研究

Research on the Collision Characteristics of Mini Bus

汽车安全性是现代汽车设计的基本出发点之一为了提高汽车的安全性，人们采用了各种各样的主动和被动安全措施，但从根本上来说，车辆的碰撞是不可避免的，所以车辆本身的碰撞特性才是最终的安全性能决定因素本文旨在通过研究现有结构的碰撞动态特性，改进车辆结构，达到最佳的吸能特性，从而提高车辆的安全性研究中采用的方法是有限元计算，工具软件是ＡＮＳＹＳ／ＬＳ－ＤＹＮＡ３Ｄ模型的建立是以张家港牡丹客车厂生产的ＭＤ６６０１型客车为原形，这种车是以货车底盘改装的，车架的吸能占７０％以上，所以本文重点考虑了车架和保险杠，把其它部分作为集中质量加在车架上通过计算得出了碰撞过程的位移量、转角、撞击力、冲量、能量吸收等量的时间历程曲线，分析这些曲线即可对车辆的碰撞安全特性进行评价研究发现碰撞行为有它的一般规律：碰撞时间在１００ｍｓ以内，变形集中在碰撞接触点附近，撞击力可达车重的上百倍，碰撞过程接近平动等观察碰撞变形图可以知道车架各处的变形情况。

Security of automobile is one of the principle of modern automobile design.Various kinds of initiative and passive measures are taken to improve automobile security. But the collision of vehicle cannot be avoided radically, so the collision characteristics of vehicle itself is the final determinant of security. To get the best energy absorbing characteristics and improve security,the dynamic characteristics of collision for structure in existence is studied. The finite element simulation with software ANSYS/LS DYNA3D is carried out. The original model is MD6601 bus of Peony Bus Factory, the bus is refit from truck chassis, energy absorbing of the chassis is more than 70% of total energy, so the frame and bumper are studied stressly, other parts are taken as point mass and put on the frame.The displacement,rotation,force,impulse,energy absorbing curves are obtained from calculation,and security evaluation can be made from analyses of the curves. The commonly collision law is that impact time is within 100ms; deformation centralizes on the point of impact; impact force can reach 100 times that of vehicle weight. Deformation at different points can be known from observation of deformation figure, and it is easy to improve bad structure. Accuracy of software calculation is validated.