基于桥面不平顺的车桥耦合振动分析

把车辆和桥梁结构看成相互作用的两个子系统,分别建立二者的力学模型和振动微分方程。在求解过程中,通过位移协调条件和两个子系统间相互作用力相等的原则把两个子系统的振动微分方程耦合起来。利用有限元分析软件ANYSYS的二次开发语言APDL编写了求解车桥系统耦合振动微分方程的迭代计算命令流。以桥面不平顺为激振源,分析了主跨为550 m的福建长门大桥当多车辆通过时在各级桥面不平顺情况下的动力响应。计算结果表明,随着桥面不平顺程度的增加,桥梁结构和车体的动力响应均呈非线性增大,其中桥梁主跨跨中位移、主跨最外侧拉索应力和车辆加速度变化显著。

The Analysis on Vehicle-bridge Coupled Vibration Due to Bridge Pavement Surface Roughness

The vehicle and bridge structure are taken as two interactive subsystems, and the mechanics model and vibration differential equations of them are respectively established. During calculation, the differential equations of two subsystems are coupled by the conditions of geometric compatibility and the principle that the interactive forces between the two subsystems are equivalent. The iterative cal- culation command stream to solve coupled vibration differential equations of vehicle-bridge system is com- piled by APDL language for secondary development in finite element analyzing software ANSYS. The road roughness is taken as excitation source and the dynamic responses of Fujian Changmen cable-stayed bridge with main span of 500m are analyzed under road surface roughness for each gra~te when multiple vehicles pass the bridge. The results calculated indicate that the dynamic responses of both bridge structure and vehicle nonlinearly increase with the increment of bridge pavement surface roughness. The variation of displacement at midpoint of main span, the stress of the outermost cabie in main span and vehicle acceleration is significant.