体-壳混合单元与实体单元在构架强度计算中的对比分析

Analysis of calculation of frame strength comparing carbody and shell in-one with solid car-body

采用体单元与体-壳混合单元分别对某型地铁车辆构架进行数值模拟,模拟计算中针对体单元与壳单元自由度不同的问题,使用多点约束法(MPC)在体壳单元接触面建立连接。计算结果表明,两者的位移与应力分布情况一致,体-壳混合单元与实体单元位移值大小相同,但最大应力强度值小于实体单元,最大相对误差为8.3%,处于精度允许范围内,两者均满足构架静强度要求。

This paper carries out the numerical simulation of a metro vehicle truck frame by using the car-body and the car-body +shell hybrid element. In the simulation calculation, the multi-point constraint method (MPC) is used to establish the connection between the shell element contact surface and the shell element with different degrees of freedom. The results show that the displacement and stress distribution of the two are consistent. The displacement value of the carbody+ shell hybrid element is the same as that of the solid element, but the maximum stress intensity is smaller than the car-body solid element. The relative maximum error is 8.3%, which is within the allowable range of accuracy. Both satisfy the static strength requirement of the truck frame.