【作者】 安忠海；

【导师】 袁卫宁；

【作者基本信息】 长安大学 ， 结构工程， 2009， 硕士

【摘要】 随着社会的进步,车辆运行速度不断加快,车流密度日益增加,车辆载重也逐渐增大。高速行驶的车辆对所通过的桥梁产生动力冲击作用,使桥梁发生振动,直接影响桥梁的工作状态和使用寿命。因此,对车辆一桥梁动力相互作用进行综合研究,是合理进行桥梁设计的需要。目前,国内外对于铁路桥梁研究的较多,取得了很大的成果,对于公路桥梁的研究却相对落后,无论是实验研究还是有限元分析只是停留在对构件的研究阶段。本文总结已有的桥梁振动理论和动力有限元理论,利用大型有限元软件SAP2000建立了曲线钢—混凝土结合梁桥的全桥有限元模型,通过对该桥的静力分析、模态分析和考虑车速、车道和车辆数量的车辆荷载时程分析,对桥的动力性能进行了研究。分析表明:利用SAP2000建立了全桥有限元模型,分析桥梁的动力性能是可行的。桥梁的低阶振型起主要作用,但不能忽视高阶振型的影响;考虑了动力荷载空间分布的Ritz向量分析方法能够在模态分析中得到更精确结果;对于曲线弯梁桥,弯扭耦合作用影响明显;动力效应显著的提高了外箱梁和内箱梁底板的应力差;车辆以不同的速度在中车道行驶时,外箱的动力效应更明显;车辆在不同车道行驶时,内箱上部桥面板所受应力方向作用不同;车辆的行驶车道对桥梁的动力作用影响明显;车辆在外车道行驶时,对内箱的动力影响较大;在车辆行驶激发的桥梁振动中,由于桥面板和钢箱梁的材料不同,两者的振动频率不一样,两者的振动并不是一致的;两辆车在桥梁上行驶时,桥梁的动力效应比一辆车在行驶时大,尤其是箱梁底板应力的动静比提高最大。更多还原

【Abstract】 With the advancement of society, the vehicle speed is accelerating, the traffic density is intensifying, and the vehicle load is also gradually increasing. The bridge vibration which generated by the high-speed vehicles influences the work status and life of the bridge.Therefore, the synthetic study of the vehicle - bridge dynamic interaction is necessary to the bridge design. At present, most of the domestic and foreign researches focus on the railway bridges .The research about the highway bridge including both of the experimental study or the finite element analysis remain in the component analyzing period.This paper summarizes the existing bridge vibration theory and dynamic finite element theory, using the large-scale finite element software SAP2000 to establish full-bridge finite element model of the curvilinear steel - concrete composite girder bridge. Through static analysis, modal analysis and time-history analysis considering speed, lane and vehicle number of the bridge, the dynamic performance of the bridge were studied.Analysis showed that: it is feasible to use SAP2000 to establish a full-bridge finite element model and to analyze the dynamic performance of the bridge. The bridge’s low-level vibration mode contributes a major role, but the impact of higher-order vibration mode can not be ignored. the.The Ritz vector analysis method considering the spatial distribution of dynamic load presents more accurate results.For bending curve girder bridge, the coupling impact of bending and torsion is obviously. Dynamic effect significantly increased stress difference between the outside box girder and the inside box girder.When the vehicles travelling on the middle lane at different speeds , the dynamic effect of the outside box girder is more obvious.The stress direction on bridge deck above the inside box girder varies to the different lanes on which the vehicles are travelling. When the vehicles travelling on the outside lane ,dynamic effect of the iutside box is more obvious.For the bridge vibration stimulated by the vehicles, because of the different materials used in the plates and the steel box girders, the vibration is not consistent. The dynamic effect on the bridge by two cars is greater than single car, especially the dynamic-static ratio of the stress on the box backplane increases most.更多还原