局部集中质量接触单元法在梁式桥梁体与桥台碰撞问题模拟中的应用

近年来,模拟碰撞问题的接触单元法已经广泛运用于桥梁碰撞问题当中。其中集中参数接触单元法把碰撞两物体各自简化成质点,无法表达出碰撞应力波的传播现象;另一类Watanabe和Kawashima接触单元法,其碰撞单元的刚度是一种仅为满足精确模拟碰撞过程而采用的虚拟刚度,并无物理意义。针对梁式桥梁体与桥台的碰撞问题,该文首先提出一种新的碰撞问题模拟方法—局部集中质量接触单元法,然后详细地介绍了其在梁式桥梁体与桥台碰撞问题模拟中的应用,并通过试验验证了该方法模拟梁体与桥台碰撞的合理性。最后将该方法与两种接触单元法进行了比较,说明了该方法在模拟梁体与桥台碰撞问题中的优势。

APPLICATION OF CONTACT ELEMENT METHOD FOR LOCAL LUMPED MASS TO COLLISION SIMULATION BETWEEN GIRDER AND ABUTMENT OF BRIDGES

In recent years, some kinds of contact element methods for simulating collision issues have been widely used in the field of bridge collisions. One of them is the Lumped Parameters Contact Element Method (LPCEM), which simplifies a collision object to be two particles respectively. Consequently, the collision stress wave propagation phenomenon cannot be exhibited. Another one is the Watanabe & Kawashima Contact Element Method (WKCEM), whose contact stiffness is the virtual stiffness made for the accurate simulation of collision processes, but has no physical meaning. For the collision simulation between the girder and abutment of girder bridges, a new method, i.e. the Contact Element Method of Local Lumped Mass (CEMLLM), was put forward and introduced first. Then its applications in the collision simulation between the girder and abutment of girder bridges were discussed in details, and its rationality was verified by an experiment. At last the CEMLLM was compared with the other two methods to illustrate its advantages in the collision simulation between the girder and abutment.