Nonlinear Analysis of Reinforced Concrete Members Subjected to Combined Torsion and Bending Moment

This study aims to develop a torsional behavior model for reinforced concrete (RC) members subjected to torsional moment combined with flexure. In the suggested method, the cross section of an RC member is idealized by using a thin-walled tube consisting of shear panel elements, where the shear flow is developed along its perimeter zone. Those panels are further divided into the compression and tension zones considering the normal stresses induced by flexural moment. The panel elements subjected to combined shear and normal stresses induced by torsional and flexural moments, respectively, are then analyzed by using the softened truss model. The multiple failure criteria are addressed to identify the failure mode and determine the ultimate strength of an RC member. Based on the detailed verifications by comparisons of test results collected from literature with those estimated by the proposed method, it was concluded that the proposed method can capture the torsional responses of RC specimens with a high level of accuracy.