多点锚固预应力CFRP带加固T梁的有限元分析

采用非线性有限元分析程序ABAQUS对无粘结体外预应力CFRP片材加固简支钢筋混凝土T形梁后进行数值模拟,该模拟梁共4根分别为3根梁侧对称加固,1根为梁底加固均为四点波形齿锚固预应力CFRP带。对比结果显示,数据模拟与试验结果在构件屈服以前的承载力、变形以及极限承载力吻合程度较好,构件屈服以后的变形差别较大,因此,可在一定程度上有效替代试验分析方法。依据吻合程度最好的TL3参数设计了“两点锚固”和“四点锚固”的模型进行模拟分析。通过对锚固点数及加固量改变的对比分析可知,依据加固构件的弯矩改变各段加固量及布置锚固点数的方法既可以保证加固效果不降低,又可以节约CFRP材料。

FEM analysis of RC T-beams strengthened with unbounded pre-stressed CFRP belts anchored on multiple points

Four simply supported reinforced concrete T-beams strengthed with externally unbonded prestressed CFRP belt were simulated by nonlinear finite element analysis using the general purpose commerical program ABAQUS. Three beams were strengthed on each side symmetrically and one beam was strengthed on bottom based on a four-point tooth waveform anchor.The analytical results show good agreement with test results on flexural capacity, elastic deformation, and ultimate flexural capacity.However the inelastic deformation of the analytical simulation has significant discrpency with that observed in the test.Therefore, to some extent, the finite element analysis can be an effective alternative to the experimental test. Based on the parameters of TL3 beam which shows the best match between the finite element analysis and the test, "two-point anchoring" and "four-point anchoring" models were designed and simulated. By comparing the results of "two-point anchoring" and "four-point anchoring" models, the method for changing the amount of CFRP and the number of anchor points based on the moment of member can not only ensure non-reduction of strengthing effect, but also can save CFRP material.