Behavior of Square Concrete-encased CFDST Members under Pure Torsion
To study the behavior of square concrete-encased CFDST members under pure torsion,a calculation formula for torsional bearing capacity was proposed.The ABAQUS was used to establish the model of square concrete-encased CFDST members,the working mechanism of the members under pure torsion and the important parameters affecting the bearing capacity of the members were analyzed.Finally,the pure torsion calculation formula was proposed by the superposition method.The whole process of stress can be divided into three stages:elastic stage,elastoplastic stage,plastic stage.In the elastic stage,the members were subjected to synergistic force,and an interaction force was generated,but it was relatively small.In the elastoplastic stage,the outer concrete was separated from the steel tube and no interaction occurs.The working mechanism of members under pure torsion was analyzed,and the outer steel tube's strength,diameter and diameter thickness ratio were important parameters affecting the torsional bearing capacity of the members.The deviation between the calculated value of the pure torque formula obtained by the superposition method and the simulated value of the finite element was within basically 10%,and the formula was relatively reliable.The square concrete-encased CFDST members have good torsional bearing behavior,and the pure torsional formula proposed in this paper based on the superposition principle can better calculate its torsional bearing capacity.
square concrete-encased CFDST memberspure torsionfinite element analysisworking mechanism
万方数据
维普
