碳纤维布加固复合受力钢筋混凝土箱梁抗扭性能的非线性有限元分析

采用有限元方法对碳纤维布加固钢筋混凝土构件进行非线性分析,是对有限的试验研究的有效补充和进一步深入探讨。根据4根碳纤维布加固钢筋混凝土箱梁的试验研究结果,建立了合理的三维有限元模型,对碳纤维布加固钢筋混凝土箱梁在弯剪扭复合受力下的抗扭性能进行了非线性有限元分析。计算得到的扭矩-扭转角关系曲线、钢筋和碳纤维布的应变曲线以及界面粘接单元的恢复力曲线等与试验结果吻合较好,可以较好地模拟碳纤维布加固箱梁的受扭性能。进一步通过对7根数值梁的计算结果分析,提出碳纤维布加固钢筋混凝土箱梁在复合受力下的剪扭相关性符合直线方程。

NONLINEAR FINITE ELEMENT ANALYSIS ON TORSIONAL BEHAVIORS OF FRP STRENGTHENED RC BOX BEAMS UNDER COMBINED LOADINGS

Based on experimental results of four reinforced concrete box beams strengthened with fiber reinforced polymer (FRP), a 3-D finite element model was established and the nonlinear finite element method was used to study the torsional behaviors of FRP strengthened reinforced concrete box beams under combined loadings of bending moment, shear and torque. The numerical results of torque-twist angle relationships, strains in steel bars and FRP, forces of interfacial element showed good agreement with the experimental results. This indicates that the nonlinear finite element method can simulate the torsional behavior of FRP strengthened box beams. Further investigation was conducted with respect to the shear-torque behavior of FRP strengthened reinforced concrete box beam. The calculated results of seven numerical box beams indicated that dimensionless correlation of shear and torque strength of FRP strengthened RC box beams under combined bending, shear and torque was linear.