CFRP加固混凝土梁抗弯有限元模拟

Finite element analysis of concrete beams strengthened in flexure with hybrid anchored strap of CFRP

纤维增强复合材料(CFRP)因其高强、轻质、耐腐蚀等特点逐渐取代了传统的加固材料,被广泛应用于混凝土加固结构中。对于外贴FPR加固钢筋混凝土梁,发生剥离破坏是常见的破坏形态。为模拟CFRP加固梁的剥离破坏过程,探究其破坏机理,采用ABAQUS软件建立了FRP加固梁的三维精细化有限元模型,选取合适的材料模型,充分考虑了CFRP布条带与混凝土界面间的黏结滑移关系,对2根未加固及2根CFRP粘贴加固的试验梁进行了非线性有限元模拟,与试验结果比较表明:所建立的模型能够合理预测各试验梁跨中挠度、CFRP应变和钢筋应变随荷载的变化曲线、裂缝发展情况以及抗弯承载力和破坏模式,均与试验结果吻合较好,其中,极限荷载模拟值与试验值的相对误差在5%以内;通过CFRP与混凝土之间滑移范围的变化,可以清楚了解界面剥离发生、发展的过程,进而模拟出纯粘贴加固梁的中部剥离及混凝土压碎典型破坏模式。

Fiber reinforced polymer(CFRP)is widely used in reinforced concrete structures because of its high strength,light weight and corrosion resistance.In order to simulate the stripping failure process of CFRP reinforced beams and explore its failure mechanism,ABAQUS software is used to establish a fine finite element model,and the appropriate material model is selected considering the bond slip relationship between CFRP strip and concrete interface,two unreinforced and two CFRP reinforced test beam nonlinear finite element simulation is constructed.Compared with the experimental results,it is shown that the simulation model can predict the variation curves of mid-span deflection,CFRP strain and steel strain with load,crack development,flexural capacity and failure mode of each experimental beam,and the relative error between the simulated ultimate load and the experimental value is within 5%.Based on the variation of slip range between CFRP and concrete,the occurrence and development process of interface stripping can be clearly understood,and then the typical failure modes of central stripping and concrete crushing can be simulated.