Experimental study on concrete-filled stainless steel tubular stub columns under axial compression load

Abstract

Axial compression tests were conducted on twenty-four concrete-filled stainless steel tubular (CFSST) stub columns with circular and square cross sections to study the performance. The failure modes, loaddisplacement curves, loadstrain curves, and the effects of stainless steel tube wall thickness and concrete compressive strength on the axial compression capacity of the specimen were investigated. The finite element (FE) models were established to study the failure mechanism of columns with different cross sections types and the restraining effect of steel tube on concrete. The results indicated that the stress development and failure mechanism of CFSST stub columns with square cross sections are more complex compared with the CFSST stub columns with circular cross sections. In addition, a formula for calculating the axial compressive bearing capacity for CFSST stub columns was proposed by regression analysis and theoretical derivation. The formula had high accuracy and its calculation results were more consistent with the experimental data.