摘要
索桥是大变形柔性组合结构,其受力分析属于几何非线性问题,求解较复杂。本文应用有限元方法,结合索桥结构特征,提出三节点二次曲线元与直梁单元相结合的混合有限元模式。由Reissner广义变分原理导出有限元运动方程。用Newton-Raphson方法求解有限元平衡方程,用FORTRAN-77语言编制了相应的计算程序。并以跨距为200米的索道桥为实例进行几种载荷作用下的静力分析计算。计算结果与实测值对比显示出很好的一致性。表明混合有限元模式是有效的。
Cable-bridge is combined structure consisting of flexible cable with large deformation. Its deformation has geometric nonlinear property. To study it is difficult. In this paper, using finite element method and considering structural characters of cable-bridge, the authors present method combining quadratic curve elements and straight beam elements in one modal. The finite element kinetic equation is built up using Reissner's generalized variational principle. The finite element equilibrium equations are solved with Newton-Raphson scheme. Computer programs are written in FORTRAN-77. . As a practical example, calculation and analysis for the span 200 meters' cable-bridge in several load cases are done.Calculating results are good coinciden twith experimental results. It is shown that the mixed finite element modal is correct.
