大跨径钢管混凝土拱桥非线性静风稳定性

针对大跨径钢管混凝土拱桥的特点，对其空气静力失稳问题作了理论和数值计算分析。基于虚功原理对钢管混凝土拱桥几何非线性问题的有限元分析方法进行了描述，推导出切线和割线刚度阵；在综合考虑静风荷载与结构非线性影响的基础上，利用增量法和内外两重循环相结合的方法寻找各级风速下结构变形平衡位置，并精确求解大跨径钢管混凝土拱桥静风稳定性；通过数值全过程分析得到了结构失稳行为的全过程变形曲线和失稳临界风速，并编制了相应的计算程序。实桥数值分析计算结果表明，其静风失稳为桥面弯扭耦合的失稳形态。

Aerostatics Stability of Long-span Concrete-filled Steel Tube Arch Bridge

Based on the characteristics of the bridge, the aerostatics instability of long-span concrete-filled steel tube arch bridge is analyzed. The finite element analysis method for the geometry non-linearity problems of the bridge is described on virtual work principle, the tangent and secant stiffness matrixes are derived. Considering the nonlinear influences caused by structure and aero- statics load, a finite element procedure combined with increment method and the inner-outer iteration method is proposed for determining the aerostatics stability. The equilibrium position of the structure deformation under each wind velocity and the critical velocity of the structure can be get accurately in this method. The numerical calculation results show that the instability conformation is the lateral-torsional buckling instability form. 1 tab, 8 figs, 7 refs.