轴压FRP约束有拐角的方形混凝土短柱的数值模拟研究

Numerical simulation study on FRP confined square concrete short columns with corners under axial compression

采用非线性有限元分析程序ANSYS,选取Shell181单元模拟分层FRP,假定混凝土达到抗压强度后强度不变,对轴压下FRP约束有拐角的方形混凝土短柱受力过程进行了数值模拟。分析表明非线性有限元计算结果与试验结果吻合良好。从FRP对混凝土约束作用的分析可知,FRP对有拐角方形混凝土截面的约束主要集中在角部,FRP对混凝土的约束应力与轴向压应力的关系曲线均呈现出有规律的梯次递进式的变化。从裂缝发展过程看,混凝土开裂主要发生在柱两端,由角部开始再发展到中部。

By using nonlinear FEM program ANSYS,the mechanical behavior of FRP confined square concrete short columns with corners under axial compression were analyzed.Shell181 was selected to simulate FRP layers.It was assumed that the strength of concrete is constant after achieving compressive strength.The nonlinear FEM analysis results are in good agreement with experimental results.The constraint to square concrete section emerges in corners generally.The constraint stress verses axial stress curves trend to a regular and progressive rendering.Concrete cracking takes place in column ends mainly,from corner to center.