Abstract：To investigate the mechanical behavior of box concrete filled steel tubular specimens under pure torsion, 13 model specimens were analyzed by ABAQUS. The stress changes of concrete, section steel and reinforcement during cracking and failure were discussed. Based on the traditional superposition principle of bearing capacity, the torsional bearing capacity of steel reinforced concrete members was improved. The results show that the stress changes of different concrete specimens are similar before cracking. When the specimen reaches the limit state, the steel tube and part of the stirrups yield basically, and the steel bar with longitudinal stress is not yielded with the cracks of cracked concrete developing in the direction of 45 degrees. The error between calculated bearing capacity and numerical simulation value is small, which proves that the improved bearing capacity superposition method is reasonable with accurate correction coefficient.
2018, Vol. 39 
