simulation of nonlinear behaviour of rc joints with 180°-hook under varying axial load

in this study, an analytical model for predicting the nonlinear behaviour of exterior reinforced concrete (rc) beam-column joints under varying axial load has been developed. the main focus was on the assessment of effect of axial load variations on response of rc joints. according to experimental evidences, it can significantly affect nonlinear behaviours, i.e. bond mechanism and shear failure of rc beam – column joints. to simulate these nonlinearities, a joint model including a rotational spring in the joint core and some rotational springs in other parts has been developed. the joint spring characteristics could be computed using proposed principal tensile stress - rotation relation in the joint core. a new methodology was also developed to consider the effects of the axial load variations in determining characteristics of rotational springs. the verification results showed that the proposed model would accurately predict the experimental response of joints under varying or constant axial loads.