某斜拉桥拉索损伤对其动力特性的影响研究

摘要

本文以某特大斜拉桥为工程背景,基于有限元软件,结合桥梁原始设计资料,建立了桥梁动力计算模型,对斜拉桥拉索损伤进行模拟研究.通过拉索有效面积的变化对斜拉桥拉索损伤进行模拟,分析不同拉索损伤下斜拉桥自振频率的变化规律,得出斜拉桥拉索损伤对竖向弯曲振型影响较大,而对侧向弯曲和扭转振型的影响较小的结论.同时,也认识到长索区拉索损伤对斜拉桥低阶振型影响较大,相反,短索区则对斜拉桥高阶振型的影响较大.%Taking a super cable-stayed bridge as background and combining with the original design information, a bridge calculation model is set up based on finite element program to simulate influence of cable damage on dynamic characteristics. The law of the dynamic characteristics with different damage is studied through the decrease of the lasso effective area. It can be conclude that the influence of cable damage has bigger influence to vertical bending mode than that on lateral bending and twisting vibration model. It is also realized that the change of higher modes is bigger when long lasso damage, on the other side, the change of lower modes will be large when the lasso damaged is in short area.