A Strain Based Non-linear Finite Element Analysis of the Exterior Beam Column Joint

Abstract

The aim of the present work is to study the behavior of an exterior RC beam-column sub assemblage in a building frame. A nonlinear analysis is carried out up to the yielding of the reinforcement both in compression and tension zone subjected to monotonic loading. The analysis up to the failure of the exterior beam-column joint is carried out using a FE based numerical model. A strain based nonlinear finite element analysis program is developed using 2D plane stress formulation, modified compression field theory, concept of equivalent principal strains, smeared rotating crack approach and secant stiffness formulation in MATLAB environment. The concrete is modeled as four node isoparametric plane stress element and the reinforcement as two node bar element with two degrees of freedom at each node. A perfect bond is assumed at the interface between the concrete and the reinforcement. The load-deformation behavior of lower column, upper column and the beam is measured and compared with the linear ANSYS model and are in well agreement. Subsequently the variation in stresses and strains in the beam column joint are obtained for nonlinear zone and are presented and discussed.