有粘结预应力混凝土简支梁的非线性有限元分析

对有粘结预应力混凝土简支梁进行了非线性有限元的编程计算,采用平面四边形等参单元模拟混凝土单元,将非预应力钢筋分布到混凝土单元中。考虑材料的非线性,混凝土采用二轴应力状态下的K up fer-G erstle破坏准则。采用弥散裂缝模式,避免在混凝土开裂后重新划分单元。对于力筋的预应力,在相应节点上施加等效预压力。在非线性方程组的解法中运用综合的增量-迭代法,分级加载,在每一级荷载下反复迭代。采用位移增量,求得在各级荷载作用下的各结点位移,将计算结果与试验结果对比,验证所编程序的准确性并进行修正。

Nonlinear Finite Element Modeling of Simply Supported Bonded Prestressed Concrete Beams

A nonlinear finite element procedure used to analyze bonded prestressed concrete simply supported beams was presented.Quadrilateral isoparametric elements were used to simulate concrete.Regular reinforcement was distributed into concrete. The influence of material nonlinearity was considered.The Kupfer damage criterion was utilized.Case of yield of regular reinforcement was treated after crack.Smeared cracking model was used to avoid meshing elements again after cracking.The equilibrium equation was solved by increment-iteration method.Displacement increment was applied as convergence criterion in which displacement of nodes were obtained at every-step of loads.The nonlinear analysis results of the model are compared with the tested results which proves the accuracy of the procedure and amends the procedure.