连续梁在行驶车辆作用下的动态反应

把桥梁和车辆看作两个分离体系,把车辆视为二维非线性模型,并考虑到桥面的路面不平度影响,应用虚功原理和模态叠加法分别建立振动方程,在车辆与桥梁接触点采用接触力和位移协调的条件,利用迭代技术求解二者之间的相互作用力。以一座三跨连续梁为例,计算了该桥的动挠度曲线和相应的冲击系数。结果显示车辆在边跨行驶时中跨跨中截面的冲击系数要远大于车辆在中跨行驶时的冲击系数,桥梁在车辆动荷载作用下的冲击系数与车辆动力特性、车速、桥梁动力特性以及路面不平度等密切相关,仅仅看作桥梁基频的函数是过于简化的。

Dynamic response of continuous girder bridge under moving vehicular loads

Bridge and vehicle were treated as two separate systems,vehicle was modelled as 2D nonlinear model,the effect of road surface roughness was considered,their dynamic equations were developed by virtual work theory and mode superposition theory,their uncoupled equations were solved separately by an iterative procedure while the geometrical compatibility condition and equilibrium condition of the interaction forces between bridge and vehicle were satisfied. The dynamic response of continuous girder bridge under moving vehicular loads was studied.The results show that the impact parameter when vehicle moving on side span is larger than the one when vehicle moving on middle span,the impact parameter is related to those factors,such as the dynamic properties and velocity of moving vehicle,the roughness of road profile and the dynamic properties of bridge,it is too simplified to take the impact parameter only as the function of the nature frequency of bridge.4 figs,14 refs.