Analytical model for beam column joint in RC frames under seismic conditions

Beam column joint in reinforced concrete (RC) frames is a crucial zone, the integrity of which is essential for the satisfactory performance of the whole structure. A new analytical model has been proposed to identify the shear behaviour of joint panel zone. Joint panel zone has been idealised as 2D element subjected to in-plane shear and normal stresses. The shear response of the joint core has been characterised by shear stress - shear strain (deformation) relationship established by softened truss model theory. Inelastic behaviour associated with the slip of longitudinal reinforcement anchored in the joint is represented through bar slippage model. The effect of cyclic load on the total response of the structure is obtained through proper hysteretic modelling of beam, column and joints. The behaviour of joints has been studied by carrying out non-linear dynamic analyses on experimental sub-assemblages under cyclic loads. Good correlation between predicted and test results were obtained.