碳纤维布加固混凝土框架静力非线性分析

从Euler梁控制微分方程出发,采用力插值函数和五结点Cotes积分推导了五区段变刚度梁单元刚度矩阵;通过比较分析,选择合适的混凝土应力-应变模型以模拟横向纤维箍对混凝土的约束效应,采用带下降段的四折线型弯矩-曲率本构模型并对其下降段刚度作了合理修正,分析了单元的刚度状态及状态转换。对试验框架进行的数值模拟表明,分析结果与试验结果吻合良好。

Nonlinear static analysis of concrete frames strengthened with CFRP sheets

Based on the governing differential equations of Euler beams,the stiffness matrix of varying stiffness beam elements is deduced using the force interpolation functions and the Cotes scheme with five integration points.By comparative analyses,a stress-strain model is selected to simulate the concrete confined with CFRP wraps.The moment-curvature relationships are simplified and the quadrilinear form with curvature-softening behaviour was properly corrected.The stiffness state and its transition are also analyzed.Numerical analyses of frame experiments are carried out,and the numerical results agree well with the results of tests.