震损后圆钢管混凝土柱耐火性能有限元分析

Finite element analysis of concrete-filled circular steel tubular columns subjected to post-earthquake fire

为研究圆钢管混凝土柱经历地震损伤后的耐火性能,选取了合理的地震损伤指数及材料本构模型,采用有限元分析软件ABAQUS,对钢管混凝土柱在往复荷载和火灾等不同工况下的试验进行了数值模拟验证。在验证模型可靠性的基础上,利用ABAQUS中的数据传递功能,建立了震损后圆钢管混凝土柱耐火极限有限元计算模型。以圆钢管混凝土典型轴心受压柱为分析对象,对其先后经历地震和火灾作用下的破坏形态、损伤机理进行了分析,研究了损伤指数对圆钢管混凝土柱震后耐火极限的影响。结果表明:震损后圆钢管混凝土柱在高温下的破坏形态是在前期地震损伤基础上的发展和蔓延;地震损伤指数是影响圆钢管混凝土柱震后耐火极限的重要参数,随着地震损伤指数增大,圆钢管混凝土柱的耐火极限有所减小。

In order to study the fire resistance of concrete-filled circular steel tubular columns subjected to postearthquake fire,reasonable seismic damage index and material constitutive model were selected. The finite element( FE) model of concrete-filled steel tubular columns under cyclic loading and fire was developed by finite analysis software ABAQUS. The FE model was verified with corresponding experimental tests. On this foundation,using data transfer function in ABAQUS,the finite element model for fire resistance of concrete-filled circular steel tubular columns after earthquake was established. Taking the typical axial compression member of circular concrete-filled steel tubular column as analysis object,the failure mode and damage mechanism of member subjected to post-earthquake fire were analyzed. The influence of damage index on the fire resistance of concrete filled circular steel tubular columns was studied. The results shown that the failure mode of concrete-filled circular steel tubular column under high temperature is developed and spread on the basis of the early earthquake damage. Damage index is an important parameter affecting the fire resistance of the concrete-filled steel tubular column subjected to post-earthquake fire.With the increase of damage index,the fire resistance of concrete filled circular steel tubular columns decreases.