车辆荷载作用下斜拉索参数振动分析

Parametric vibration analysis of stay cable under vehicle load

当外部荷载激励的频率与斜拉索自身的频率呈一定倍数关系时,斜拉索便会发生参数振动,产生非常大的位移响应,会给车辆、行人、桥梁以及拉索本身带来非常严重的灾害,这一现象也引起了学者和社会各界的高度关注。以某超大跨度斜拉桥作为研究对象,采取ANSYS有限元分析法,考虑车桥耦合以及桥面不平顺等因素,研究斜拉索在车辆荷载作用下发生大幅值参数振动的可能性。研究表明,由于斜拉桥有限速要求,若桥面上车辆都在规定时速内行驶,斜拉索不会发生大幅值参数振动。

When the frequency of external load excitation is proportional to the frequency of the cable,the cable will have parametric vibration and produce a very large displacement response,and will bring very serious disasters to vehicles,pedestrians,bridge and cable,which has attracted the attention of scholars and the public.Taking a super-span cable-stayed bridge as the research object,this paper adopts ANSYS finite element analysis method to study the possibility of large value parametric vibration of cable-stayed cable,considering vehicle-bridge coupling and deck irregularity and other factors.Due to the speed limit requirement of cable-stayed bridge,the research shows that if the vehicles on the bridge are running at the specified speed,the displacement excitation of the cable will not cause large parametric vibration of the cable.