实心和空心钢管混凝土的统一纤维模型

采用纤维模型是进行结构整体分析的一种有效手段,目前已有部分学者给出了实心钢管混凝土的纤维模型计算方法,但是缺乏关于空心钢管混凝土的纤维模型计算方法。为了给钢管混凝土的整体分析提供数值分析手段,在统一强度承载力公式的基础上,给出了实心和空心、圆形和多边形完全统一的基于材料的钢管混凝土纤维模型,并给出了考虑截面形状和空心率影响的约束混凝土的滞回本构及参数取值方法。通过对不同截面形式的钢管混凝土长短柱轴压试验、侧推试验以及滞回试验的比较和分析,证明了基于材料的纤维模型和相关参数取值的适用性。

A UNIFIED FIBER ELEMENT MODEL FOR SOLID AND HOLLOW CONCRETE-FILLED STEEL TUBE

Fiber element method is an efficient method for structural integrity analysis. There are some calculation methods for fiber element model of solid concrete-filled steel tubes( CFST),but rare for hollow CFST. This paper provides a unified fiber element model for CFST columns which is applicable for all solid,hollow,circular and polygon members,based on a unified formula of bearing capacity for CFST. The proposed model is intended to be used as a numerical approach for integrity analysis of CFST structures. The hysteretic constitutive model of confined concrete and some key parameters are also presented with considering effects of shapes of the sections and hollow ratio. The suitability of the material-based fiber element model is verified by comparing the results of axial load tests of long and short columns with different section shapes,to those of pushover tests and cyclic tests.