移动车辆荷载作用下梁桥的强迫振动分析

Analysis of the forced vibration of the beam bridge under the load of moving vehicles

桥梁在移动车辆荷载作用下的振动分析是工程设计中有待进一步解决的问题之一。采用单自由度弹簧质量模型对梁桥在移动车辆荷载作用下的动力响应问题进行了分析,给出了不同车速情况下的简支梁桥跨中动扰度的时程曲线,并与采用无限自由度模型方法的近似解进行了比较,计算结果几乎一致。文章对直观地了解桥梁与车辆耦合系统的动力特性的基本现象和机理有一定的参考价值。

To get an exact solution of the forced vibration of the beam bridge under the load of moving vehicles is difficult in the engineering design. In this paper, the dynamic response problem of the beam bridge under the load of moving vehicles is analyzed by using a single-degree-of-freedom spring-mass model. A calculation example is presented,and the maximum dynamic deflection of the beam bridge under the conditions of different speeds of a vehicle is calculated and compared with the approximate solution which is based on the infinite-degree-of-freedom model. The calculation results by the two methods are nearly unanimous. This study is valuable to the understanding of the dynamic properties of the bridge-vehicle coupling system.