Numerical simulation of application effect of FRP on torsional-flexural behavior of RC columns

Abstract

Regarding to significant effects of torsional loads as well as axial and flexural loads on columns under earthquake loads, strengthening and confinement of the concrete columns with Fiber Reinforced Polymer (FRP) layers is accounted as an appropriate technique to enhance the torsional strength of the column. In the present paper, the numerical simulation of torsional performance of the columns, flexural and axial loads are simultaneously considered. The experimental results from the authors on columns with and without FRP reinforcement with different configurations are used to validate the numerical results. Finite element method and software ABAQUS are applied for simulation. The behavior of concrete is simulated using damaged plasticity model and the behavior of the steel is defined with coordination of yield and ultimate points using bilinear model. Whereas the cyclic loads are applied to the column, the kinematic hardening is used and also the effects of large deformations on the behavior are considered. Moreover, the nonlinear static analysis is applied and the displacement based loads are applied to the models in accordance with experimental loads. The numerical and experimental results are compared and shows less than 5% error.