Finite element modeling of RC shear walls strengthened with CFRP subjected to cyclic loading

Abstract

This paper presents a numerical modeling of RC shear walls using ANSYS finite element program. The objective of this research is to study the effect of using FRP sheets to enhance the seismic behavior of RC shear wall buildings designed according to old code provisions. These structures exhibit a number of structural problems such as insufficient shear reinforcement and poor concrete confinement at the boundaries. The walls were subjected to monotonic and reversed cyclic loading up to failure.In this research, response of FRP-retrofitted RC shear walls subjected to lateral loads is studied using the general-purpose finite element code ANSYS. The numerical modeling is first validated against available experimental results from the literature. A total of seven wall specimens from two experimental programs were modeled and analyzed under monotonic and reversed cyclic loading. The FRP sheets are used in both the vertical and horizontal directions of the walls to enhance stiffness, flexural strength, shear capacity, ductility and concrete confinement of the walls. The analytical results show that FRP material is effective in eliminating the brittle shear failure mode in walls with insufficient shear reinforcement. The numerical outputs in terms of load–displacements are in good agreement with the experimental results. Keywords: RC shear walls, Seismic behavior, Monotonic loading, Cyclic loading, CFRP sheets