为了研究大跨度铁路斜拉桥的索-梁相关振动,基于拉索非线性振动理论,开发了有限元索动力单元,该单元在静力计算中为普通直杆单元,动力特性计算中可以计算拉索局部自振频率,动力时程计算中可以计算拉索非线性振动与整体结构振动的相互作用;编制了计算程序,建立了大跨度铁路斜拉桥有限元模型,同时使用索动力单元模拟斜拉索,最后研究了列车通过斜拉桥时梁、塔的带动下拉索发生索-梁相关振动的特性。结果表明:对于大跨度铁路斜拉桥,列车在设计速度范围内通过桥梁时索-梁相关振动不会导致拉索产生大幅振动。
In order to investigate cable-beam vibration in large span railway cable-stayed bridge,the cable dynamic element of finite element was developed based on the nonlinear vibration theory of cable.This element was an ordinary link element when static analysis,it could calculate the partial natural frequency of the cable in cable-stayed bridge in dynamic characteristic analysis.Meanwhile,the interaction between cables'nonlinear vibration and the global bridge vibration in dynamic time history analysis was calculated.A computing program was developed,and the finite element model of a large span railway cable-stayed bridge was built,the stayed cables were simulated by cable dynamic element.Finally,the characteristic of cable-beam vibration when train passing the cable-stayed bridge was investigated by the program.The results show that for large span railway cable-stayed bridge,cable-beam vibration cannot cause large vibration of the cable when train passing the cable-stayed bridge in the range of design speed.