采用非线性有限元方法对混凝土梁FRP粘胶层的界面力学性能进行参数化研究,并将所得的界面应力与解析解对比,吻合较好.在此基础上建立了CFS/GFS混杂加固梁界面有限元模型,并将其与双层CFS加固梁进行数值对比研究,结果表明:混杂加固可以有效地控制纤维布末端的界面剪应力,并且界面正应力也有所降低,这种加固方式具有优良的界面混杂效应.文中还就荷载、胶层弹性模量、胶层厚度、纤维布宽度对界面力学性能的影响进行了对比分析,计算结果表明:随着荷载与胶层弹性模量的增加以及胶层厚度的减小,端部界面应力成比例增加,而纤维布宽度在一定范围内变化时,端部应力基本上没有变化.
In this paper, the nonlinear finite element method is adopted to perform a parameterized analysis of the mechanical performances of concrete-to-FRP ( Fiber-Reinforced Polymer) interface, indicating good accordance of the simulated interfacial stresses and the analytical ones. Then, the interfacial finite element models of the beams respectively with hybrid strengthening ( CFS-GFS ) and two-layer strengthening ( CFS-CFS ) are established and compared, demonstrating that the hybrid strengthening is an effective method with good interfacial hybrid effect because it can control the interfacial shear stress at the FRP end and can decrease the interfacial normal stress. Moreover, the effects of such parameters as the load, the Young's modulus and thickness of the adhesive as well as the FRP width on the interfacial mechanical performances are comparatively analyzed, finding that, with the increase in load and Young's modulus and with the decrease in adhesive thickness, the interfacial stresses at the beam end proportionally increase, while keep constant when the FRP width changes in a certain range.