CFRP加固RC梁静载荷效应的有限元模拟

Finite Element Simulating of Load Effects of CFRP-strengthened RC Beams

目的应用非线性有限元方法模拟碳纤维复合材料(CFRP)加固钢筋混凝土(RC)梁承载过程中结构的载荷效应(挠度、应力应变和承载力).方法以4根CFRP加固RC试验梁的抗弯试验为依据,讨论了三维有限元分析模型的建立,包括:混凝土、钢筋、CFRP及CFRP和混凝土界面等单元的选择及本构关系原理,并选择了合适的裂面剪力传递系数.采用商业有限元计算软件ANSYS,模拟了4根CFRP加固RC梁加载的全过程.结果有限元模拟破坏承载力与实际破坏载荷基本接近,误差可控制在15%以内;有限元模拟压区混凝土、受拉钢筋、CFRP应变与实际测量应变在受拉钢筋屈服前基本一致;有限元模拟跨中挠度与试验测量挠度基本吻合.结论证明有限元方法可较好的预测CFRP加固RC梁的静载荷效应.

Abstract The load effects of carbon fiber reinforced polymers（CFRP） strengthened reinforced concrete （RC）beams are simulated with the nonlinear finite element method when the structures bear the load, Based on the flexural experiment of 4 pieces of CFRP strengthened RC beams, the building of three-dimensional finite dement model are discussed, which includes： elements choosing and the constitutive principle of concrete, steel, CFRP and CFRP-concrete interface and the choosing of the proper coefficient of interface shearing force transmission. The experimental simulation of the flexural property for the beams is completed with the commercial nonlinear finite element software of ANSYS. It is shown that the simulation results and the measuring results of strains for compressive concrete, tensile steel, CFRP laminates and mid-span deflection, ultimate flexural bearing force are nearly consistence, and this proves the validity of finite element simulation.