移动车辆荷载作用下简支箱梁动力特性的数值分析

摘要

By comparing various moving load models, a dynamic analyzing model is put forward, which applies single free mass-spring to simulate moving vehicle.The models for vehicle-bridge coupled vibration of mass-spring and roiling-mass are established by using the finite element analysis software in this paper.The dynamic response effects of both models are compared under three different moving speeds, and the reliability of the mass-spring bridge model is verified.The analysis results show that the proposed mass-spring bridge model conforms to the actual driving conditions of vehicles.The midspan displacement of the simple-supported box girder bridge is maximum and their time-path changes for dynamic displacement are sinusoidally alike; the mid-span speed and the vertical acceleration of the vehicle-bridge coupled vibration system have been greatly influenced by the moving speed.%通过比较不同移动荷载模型的差异,提出了采用单自由度质量-弹簧模拟移动车辆荷载的动力分析模型,运用有限元软件分别建立了质量-弹簧和滚动质量的车桥耦合模型,并比较了三种移动速度下两种模型的跨中动力响应结果,验证了质量-弹簧车桥耦合模型的可靠性.计算结果表明:提出的质量-弹簧车桥耦合模型更符合车辆实际行驶状态;简支箱梁桥的跨中挠度最大且动位移的时程变化呈类正弦波形;车桥耦合系统的跨中速度及竖向加速度受移动速度的影响较大.