风荷载作用下斜拉桥概率有限元分析

随着桥梁跨径的增大,风对桥梁结构的作用也越来越重要,而桥梁结构的抗风性能评价涉及到许多不确定性因素:设计风速、结构几何物理参数以及风与结构的相互作用的不确定性等。从结构几何特性以及三分力系数两个方面来讨论不确定性参数对结构静力抗风性能的影响,利用MonteCarlo数值模拟与有限元相结合的方法进行参数不确定性分析,并得到影响关键截面响应的敏感性参数;利用抖振反应谱理论计算了长江上某拟建公路大桥在成桥状态的抖振响应,同时考虑静风、脉动风作用,利用一次二阶矩(First OrderSecond Moment,FORM)方法计算主梁跨中截面可靠度指标。

Probabilistic finite element analysis of cable-stayed bridges under wind

The wind speed,geometric and material properties,interaction between wind and structure are uncertain during the design of long span bridges.The effects of uncertain parameters, including geometry, drag coefficient, lift coefficient,pitch coefficient, are important in assessing the behavior of bridge under wind. Probabilistic finite element method was employed in analyzing the effects of uncertain parameters on bridges, in which buffeting response of bridges under fluctuant wind was calculated with response spectrum method. The reliability index of the main girder of a bridge was calculated with first-order second-moment(FORM).