斜拉桥在多车辆作用下的动力响应分析

Analysis of Dynamic Responses of Cable-Stayed Bridge Under Action of Multiple Vehicles

为研究车辆偏载和车辆间距对斜拉桥动力响应的影响,以福建长门大桥(主跨为550m的双塔双索面混合梁斜拉桥)为背景进行分析。基于有限元法和动力平衡原理分别建立车辆和桥梁2个子系统的力学模型和振动微分方程。根据2个子系统之间位移协调条件和动力相互作用力相等的原则,利用ANSYS编写迭代计算的APDL命令流求解车-桥系统的振动微分方程。考虑不同偏载程度和车辆间距情况,分析桥梁结构的动力响应,结果表明:随着偏载程度的增大,桥梁结构动力响应在总体上增大,个别指标有一定的波动性和随机性;随着车辆间距的增大,桥梁结构动力响应在总体上减小。

To study the effect of vehicle eccentric loading and vehicle spacing distances on the dynamic responses of cable-stayed bridge, the Changmen Bridge （a hybrid girder cable-stayed bridge with double pylons, double cable planes and with a main span of 550 m） in Fujian was taken as an example and was analyzed. Based on the finite element method and dynamic equilibri um principle, the mechanical models and vibration differential equations for the two subsystems of the vehicles and bridge were respectively built. On the principle that the compatible displace- ment conditions and dynamic interaaetive forces of the subsystems were equivalent, the ANSYS was used to compile the APDL command stream for iterative calculation, the vibration differential equations for the vehicle-bridge system were solved and in consideration of the different eccentric loading degrees and spacing distances of the vehicles, the structural responses of the bridge were analyzed. The results of the analysis indicate that with the increase of the eccentric loading de- gree, the dynamic responses of the bridge increase on the whole, in which some of the individual indices may have certain fluctuation and randomness and with the increase of the vehicle spacing distance, the dynamic responses of the bridge decreases in general.