斜拉桥地震响应非线性时程分析

Nonlinear Time-Domain Analysis of Seismic Responses of Cable-Stayed Bridges

基于有限单元法 ,推导出多自由度结构体系在地震作用下的增量形式的运动方程 ,建立了大跨度斜拉桥的地震激励模型。考虑结构的几何非线性 ,采用增量动力平衡迭代格式的Newmark β法进行非线性时程分析 ,并以某主跨 36 0m的斜拉桥为例进行了线性、非线性动力分析 ,验证了方法的可行性 。

The incremental motion equations of a M DOF structural system excitated by seismic waves are formulated based on FEM, and a seismic response model for cable stayed bridges are proposed. Due to the geometric nonlinearity of the structure, the Newmark b method is used in the nonlinear time domain analysis. A bridge with 360 m main span is taken as an example to verify the feasibility of the method used in the study. The analysis of the bridge shows that the geometric nonlinearity of long span cable stayed bridges is not neglectable.