大跨悬索桥非线性随机静力分析

Nonlinear stochastic static analysis of long-span suspension bridge

大跨度悬索桥结构具有显著的几何非线性行为,且存在材料特性、几何尺寸的随机性.先对缆索采用较小抗弯刚度参数的梁单元,对悬索桥进行确定性的几何非线性分析;然后采用响应面法进行非线性随机静力分析;最后针对1座大跨悬索桥,计算了在竖向活载作用下材料、几何尺寸的随机性对主梁跨中位移的影响.结果表明,结构随机性的影响十分明显.

Geometric nonlinear behaviors are very significant in the long-span suspension bridges, and the uncertainties of the material, the physical dimension, etc. greatly influence the structural response of the suspension bridge. The beam element with small EI is used for the certain analysis of the suspension bridge. Based on the response surface approach, the non-linearity of the suspension bridge is researched. Finally, the mid-span deflection of a long-span suspension bridge under the vertical live load is analyzed when the elastic modulus of cables and hangers are assumed to be random correlated variables. Numerical results show that the randomness has a significant effect on the mid-span deflection.