钢桁结合梁斜拉桥非线性稳定性分析

Nonlinear Stability Analysis of Steel Truss Combined Beam Cable-stayed Bridge

基于几何和材料双重非线性理论,该文研究了连续钢桁结合梁多塔斜拉桥裸塔状态和成桥状态风荷载作用下结构非线性稳定性,并探讨焊接残余应力对桁架结构稳定承载力的影响。结果表明:风荷载作用下,裸塔状态和成桥状态风荷载作用下结构非线性稳定安全系数均大于6,非线性稳定系数比线弹性稳定系数约折减40%～50%,材料非线性比几何非线性对非线性稳定的影响大;同时,焊接残余应力对稳定系数影响较大,最大折减13%。

Based on the dual nonlinear theory of geometry and material,the article analyzes the nonlinear stability of continuous steel truss combined beam multi-pylon cable-stayed bridge under the wind load of the naked pylon and finished bridge,and discusses the influence of residual welding stress on the stable carrying capacity of truss structure.The result makes clear that the stable security coefficients of structural nonlinearity are all larger than 6 under the wind load of the naked pylon and the finished bridge,the stable coefficient of nonlinearity reduces about 40%~50% than the linear elastic stable coefficient,and the material nonlinearity more greatly influences the nonlinear stability than the geometry nonlinearity.Also the residual welding stress more greatly influences the stable coefficient and the maximum reduction is 13%.