形函数时变性对汽车公路梁桥竖向耦合振动影响分析

Effect of time variability of element interpolation function on vehicle-bridge vertical coupling vibration of highway beam bridges

采用梁单元离散公路梁桥,每辆汽车由多刚体模型模拟,将汽车与桥梁视为相互作用的整体系统,建立汽车-梁桥耦合时变系统的竖向振动方程。引入三次Hermite插值形函数,考虑车桥相互作用引起的梁单元形函数时变性,推导出形函数时变性在车桥耦合振动方程中的贡献值,并编制计算程序。通过具体算例分析梁单元形函数时变性对汽车-梁桥竖向振动响应影响。计算结果表明,在高速行车的车桥振动分析中,梁单元形函数时变性对公路梁桥竖向耦合振动影响显著,模拟计算时应予以考虑。

The highway beam bridge was modeled by beam elements,the car was simulated by multi-body model, vehicles and the bridge were taken as an interactive system,and then the vertical vibration equation of the vehicle-beam bridge coupling time-varying system was established.A three order Hermite interpolation function was introduced,and the time variability of the beam element interpolation function （TVEIF ）,caused by the vehicle-bridge interaction,was considered.The contribution of TVEIF to the equation of the bridge-vehicle system was deduced and a program was compiled.The effect of TVEIF on the vertical vibration response of the vehicle-beam bridge system was analyzed through a specific example.The results show that the effect of TVEIF on the vehicle-bridge coupling vertical vibration of highway beam bridge is significant when the vehicles are crossing the bridge with high speed,so it should be considered in vibration simulation calculation for vehicle-beam bridge coupling systems.