混凝土斜拉桥主梁的非稳态温度场与应力场分析

按非稳态温度场问题的热平衡控制微分方程和弹性力学平面应变问题的计算理论,应用变分原理给出了温度场和应力场的有限元计算列式。根据结构热分析和热应力分析的单向耦合特点提出了在同一有限元模型上按时间差分顺序耦合求解斜拉桥主梁温度场和应力场问题的方法,编写了计算机程序;并计算分析了一混凝土斜拉桥的主梁截面内温度分布和应力分布,对比了温度实测值,得出了几个重要的结论,对同类桥梁的设计具有实际参考价值。

Analysis of unsteady temperature gradient and thermal stress field for concrete girder of cable-stayed bridge

Based on the governing differential equations of unsteady temperature field and the elasticity theory of plane strain problem, finite element equations of temperature gradient and thermal stress field are given by the variation principle. Considering that thermal analysis and thermal stress analysis are unilaterally coupled, solution of applying time difference is conducted for a same finite element model in sequence. Temperature gradient and thermal stress of the concrete girder in a cable-stayed bridge are calculated by developed method. According to the distribution of the temperature and the stress field, some conclusions which have important significance for design of this kind bridge are obtained.