（东南大学交通学院  南京  210096）
【提要】  基于CB壳单元，采用层状模型模拟预应力混凝土结构，考虑材料和几何双重非线性效应，有效地模拟了三跨连续斜交箱梁的开裂、屈服和失效的全过程。结果表明，CB壳单元模型对于预应力混凝土箱梁的非线性分析有良好的适应性，对箱梁开裂后的使用性能评估有实际应用价值。基于非线性计算分析了箱梁在开裂后的刚度及裂缝的位置和发展情况，探讨了混凝土和预应力钢筋在斜交箱梁开裂后的应力发展规律，得出了若干有益的结论。
【关键词】  预应力混凝土  斜交箱梁  开裂  非线性  CB壳单元  层状模型
Nonlinear Analysis on Prestressed Concrete Continuous Skew Box Girder/Zhang Feng，Ye Jianshu （Transportation College，Southeast University，Nanjing 210096，China）
Abstract:Using CB shell element and layered model，the behaviors of cracking，yielding and destroying procedures of a threespan PC continuous skew box girder are analyzed considering the material and the geometry nonlinearity. The results show that the CB shell element could describe the nonlinear behavior of box girders well and be valuable to evaluate the serviceability of the cracked box girder. The stiffness and the stress redistribution of the box girder are researched based on the computation.The developing rule of the stress of the concrete and the rule of the steel are researched after the  skew box girder cracking are researched. Some useful conclusion are drawn based on the analysis.
Keywords:prestressed concrete； skew box girder； crack； nonlinearity； CB shell element； layered model
*江苏交通科学研究项目（04Y051）。