【摘要】 同时考虑作用在斜拉桥主梁、索塔以及斜拉索上的气弹自激力、抖振力和各构件相互之间以及各阶模态之间的耦合效应,基于随机振动的高效算法——虚拟激励法,给出了直接应用随机振动方法计算大跨斜拉桥抖振内力响应的分析过程.以某大跨斜拉桥为例进行了多工况抖振内力分析,结果表明:作用在索塔以及斜拉索上的气弹自激力和抖振力使结构与侧向运动有关的内力普遍增大;高阶模态的参与可能使结构各方向的内力显著增大,因此必须确保足够数量的参振模态.更多还原

【Abstract】 Based on the accurate and highly efficient PEM (pseudo\|excitation method), a framework for performing the buffetinginduced structural internal force analysis of longspan cablestayed bridges is presented. The buffeting forces acting on the deck, the towers and the cables are all taken into account. The correlation terms between all buffeting forces and between all participant modes are also involved in the computation. With a longspan cablestayed bridge taken as an example, the computation results show that: the structural internal forces associated with the lateral movement of the bridge will increase when the windgust acting on the towers and the cables are included. And the structural internal forces over the whole bridge may considerably increase when higher modes are included in the modesuperposition analysis, therefore sufficient modes must be used in the structural analysis.更多还原