上承式钢桁梁桥的刚度分析

Stiffness analysis of deck truss girder bridge of steel

将列车-上承式钢桁梁桥视为一个整体振动系统。上承式钢桁梁桥采用桁段有限元法离散,列车采用具有26个自由度的二系弹簧车辆空间振动模型。应用弹性系统动力学总势能不变值原理及形成矩阵的"对号入座"法则,建立列车-桥梁时变系统的整体振动方程。以车辆构架在桥上实测的蛇形波作为激振源,计算了列车以不同的速度通过上承式桥梁时列车的振动响应,分析结果表明,该上承式钢桁梁桥具有足够的横、竖向刚度。

The train and the deck truss girder bridge were coupled together as one composite system. Deck truss girder bridge was idealized as an assemblage of finite truss element and the vehicle space vibration model of two-stage suspension was used, which has 26 degrees of freedom. The equations of the train and deck truss girder bridges time varying system were set up by using the principle of total potential, al energy with stationary value in elastic system dynamics and the＂set in right-position＂rule for forming structural matrices. By taking the actual measured snake-like oscillations of bogie as excitation sources, the vibration responses of train and bridge were calculated when the train had passed through a deck steel truss girder bridge at different speeds. The results show that the bridge has sufficient lateral and vertical stiffness.