矩形钢管混凝土构件纯扭力学性能及设计研究

Research on the behavior and design of rectangular concrete-filled steel tubular specimens under pure torsion

建立矩形钢管混凝土受扭构件的有限元模型,利用现有试验数据验证了该有限元模型的正确性.利用该模型分析矩形钢管混凝土构件的荷载分配比例、组合效应对钢管和混凝土力学性能的影响规律,以及截面高宽比对矩形钢管混凝土构件刚度、承载力和混凝土抗剪强度的影响规律.基于塑形力学原理和机理分析,提出矩形钢管混凝土构件抗扭承载力的简化设计公式.该公式和现有计算公式的精度得到了81个典型有限元算例和现有试验数据的验证.

A finite element （FE） model for rectangular CFST specimen under pure torsion was built at first and the existing data was employed to verify the correctness of the FE model. Then this model was used to perform mechanism analysis. The load distribution ratio of rectangular CFST columns and the influence of ＂composite effect＂ on the behavior of steel tube and concrete were mainly analyzed. Meanwhile, the effect of the aspect ratio on the member stiffness, load - bearing capacity and shear strength of concrete was also analyzed. At last, a simplified calculating formula was recommended for the design of rectangular CFST specimens under pure torsion based on the theory of plastic mechanics and the mechanism analysis. This new formula and the existing formula were verified by 81 typical FE samples and the existing experimental data as well.