脱空缺陷对钢管混凝土滞回性能的影响分析

EFFECT OF SPHERICAL-CAP GAP ON HYSTERETIC BEHAVIOR OF CONCRETE-FILLED STEEL TUBULAR COLUMNS

在充分考虑往复荷载下钢材的包辛格效应、混凝土损伤累积以及刚度退化的基础上,合理选择构件各部件的单元类型以及部件之间的接触模型,建立反复荷载下带球冠形脱空缺陷的钢管混凝土压弯构件的有限元模型。有限元算例结果表明,计算的破坏模态和侧向荷载(P)-侧向位移(Δ)滞回关系曲线与试验结果总体上吻合良好。在此基础上,结合典型构件的有限元模型对带球冠形脱空缺陷的钢管混凝土压弯构件的滞回特性进行全过程分析,并对带球冠形脱空缺陷构件的钢管与混凝土之间的相互作用机理进行分析。

The paper developed a nonlinear finite element analysis（ FEA） model of concrete-filled steel tubular（ CFST） columns with spherical-cap gap under cyclic loading,where the Bauschinger effect of steel,the damage accumulation and stiffness degradation of core concrete under cyclic loading were all taken into consideration. The FEA model was verified by comparing with previous test results,and it showed that the predicted result generally agreed well with the test ones in terms of failure modes and P-Δ hysteretic curves. Based on the FEA model of typical members,the hysteretic behaviour of the CFST columns with spherical-cap gap was analyzed during the whole loading process,and the mechanism of interaction between the tube and concrete of members with spherical-cap gap was also analyzed.