大跨度铁路斜拉桥非线性时域抖振分析

通过脉动风速场模拟，获得了桥梁结构时域化风荷载，在此基础上，采用大跨度桥梁抖振的时域分析法，以一大跨度铁路斜拉桥为工程背景，对大跨度铁路斜拉桥抖振的非线性行为进行了分析．分析中综合考虑了结构几何非线性和气动非线性，其中结构几何非线性因素包括拉索垂度、内力引起的梁-柱效应及结构大变位等，气动非线性因素包括攻角效应、自激力等．非线性运动方程采用双重迭代法求解，以提高迭代的收敛性．非线性时域抖振分析和线性分析结果的比较表明，非线性因素会增大结构的抖振响应．

Nonlinear Time Domain Buffeting Response Analysis for Long-Span Railway Cable-Stayed Bridge

Based on the time domain wind loads obtained by wind field simulation, the nonlinear behaviors of bridge buffeting were investigated by the buffeting analysis method for long-span bridges. In the investigation, a long-span railway cable-stayed bridge was regarded as an example, and both structural geometric nonlinearity and aerodynamic nonlinear factors were taken into account simultaneously. The geometric nonlinear factors include cable sag, beam-column effect and large structure displacement, and the aerodynamic nonlinear factors are wind incidence angle effect and self-excited force. The nonlinear kinetic equation of a bridge structure was solved with the double iteration method. The comparison between linear and nonlinear analysis results shows that the nonlinear factors can result in a great buffeting response of long-span railway cable-stayed bridges.