FINITE ELEMENT ANALYSIS ON BEHAVIOR OF HCFHST MIDDLE LONG COLUMNS WITH INNER I-SHAPED CFRP UNDER AXIAL LOAD

In this paper, the behavior of high-strength concrete filled high-strength square steel tube (HCFHST) middle long columns with inner I-shaped CFRP profile under axial load was studied. The finite element analysis models were established by ABAQUS software based on reasonable material constitutive relationship models. The whole process curve of load-deformation was analyzed. In addition, effects of concrete strength, steel yield strength, slenderness ratio, steel ratio and configuration ratio of CFRP on mechanical behavior of middle long columns were studied. On the basis of the parametric analysis, the limit slenderness ratio of middle long columns was obtained. Results show that with the increase of steel yield strength, the bearing capacity increases gradually, but ductility decreases. The higher the concrete strength is, the greater the ultimate bearing capacity is. Effect of steel ratio on the ultimate bearing capacity and ductility is relatively obvious. The ultimate bearing capacity of HCFHST middle long columns with inner I-shaped CFRP profile decreases with the increase of slenderness ratio.