Generally, beam–column joints are assumed rigid while evaluating the performance of reinforce concrete (RC) structures. Post-earthquake reconnaissance and experimental studies have confirmed that joint failure can significantly affect the performance of the structure and ignoring this effect might lead to misleading results. Consequently, in this study, a new model is proposed to consider the effect of the joint, and also, the shear failure of the beam and column in a nonlinear analysis. For this, the joint was modeled using two axial springs. The characteristics of these springs were determined according to principal tensile stress–shear deformation relation in the joint core. For the joints without transverse reinforcements and with various anchorage of beam longitudinal reinforcement in the joint core, the principal stress–shear deformation relations were suggested. For the joints with transverse reinforcements in the joint core, the effect of transverse reinforcements on the shear capacity of the joint was calculated by an incremental process using Mohr Theory. In order to validate the proposed model, the results were compared to experimental tests conducted by other researchers. The results confirm the reliability of the proposed model in predicting the capacity and the failure mode of the joints.
