预应力混凝土刚构U型梁的受力性能研究

摘要

基于实体退化法,对预应力混凝土刚构U型梁的受力性能问题进行了研究.建立了实体退化单元基本模式,推导了实体退化单元的坐标表达式和位移场表达式,并得到了相应的法向力、弯矩、扭矩和剪力的内力表达式,同时基于四参数屈服准则等考虑了混凝土的材料非线性.对预应力混凝土刚构U型梁实例进行了分析,结果表明,实体退化单元能有效地模拟预应力混凝土刚构U型梁,随着加载量增大,预应力钢筋在普通钢筋屈服后应力增长迅速.研究结论可供工程设计参考.%Based on degraded solid element method,the mechanical behavior of prestressed concrete rigid frame U beam is studied.The analytic models of degraded solid element is set up and the expressions of coordinates and displacement fields are derived.Then the internal force expressions of normal force,bending moment,torque and shear force are obtained.At the same time,the material nonlinearity of concrete is considered based on the four parameter yield criterion.Through the example analysis of prestressed concrete rigid frame U shaped beam,it is shown that the prestressed concrete rigid frame U shaped beam can be efficiently modeled by the degraded solid element.With the increase of the load,the stress of the prestressed steel bar increases rapidly after the yield of the ordinary steel bar.The research conclusions can be referred to the engineering design.