车辆-路面-桥梁系统竖向振动分析

VERTICAL VIBRATION OF VEHICLE-PAVEMENT-BRIDGE SYSTEM

视车辆、路面体系和桥梁为整个系统,将车辆模拟成弹簧和阻尼器连接的多刚体,沥青路面层视为Kelvin模型及其上的无限长梁,混凝土路面和主梁一起模拟成Euler-Bernoulli梁。应用弹性系统动力学总势能不变值原理和形成矩阵的"对号入座"法则,建立了系统的竖向运动方程;并运用协方差等效方法模拟了车轮随机输入非平稳时域模型。研究了弹性支承下的车辆-路面-桥梁耦合系统的振动特性。计算表明:在其他条件相同时,混凝土路面层所对应的冲击系数约为沥青路面层所对应冲击系数的1.35倍;刚性支承对应的冲击系数约为弹性支承对应冲击系数的1.60倍,但当车速大于33.4m/s时,橡胶支座对冲击系数的影响就较小。

The vehicle, pavement and bridge are considered as an entire system. The vehicle is modeled as a multi-rigid body connected by springs and dampers, the asphalt pavement as Kelvin model and boundless beam, the concrete pavement and bridge as a Euler-Bernoulli beam. Vertical vibration equations of the system are formulated by means of the principle of total potential energy with a stationary value in elastic-system dynamics and the ＇set-in-right-position＇ rule for formulating matrices. The covariance equivalence method is used to establish the unsteady model of wheel random inputs. The dynamic responses for the coupling vehicle-pavementbridge system with elastic supports are researched. The results show that when other parameters are idential, the impact factor to the concrete pavement is aboutl.35 times of that to the asphalt pavement; the impact factor to the rigid bearing is about 1.60 times of that to the rubber bearing, and when the velocity increase to more than 33.4m/s, effect of the rubber bearing to the impact factor is small.