Compressive behavior of CFRP-confined concrete-filled double-skin stainless-steel tube stub columns

Abstract

The axial compression behavior of CFRP-confined concrete-filled double-skin stainless-steel tube (CFDSST) stub columns were investigated through experiments and FE modeling in this study. The typical failure modes, axial load–shortening curves, and strain responses of CFDSST and CFRP-confined CFDSST specimens were determined. The test results showed that CFRP could effectively restrain the local buckling and evidently enhance the compression behavior of the specimens. FE models of the CFRP-confined CFDSST stub columns were established and then validated by comparing with the experimental results. On this basis, FE modeling was used to perform parametric studies. To avoid the local buckling and yield failure of the inner steel tube prior to that of the outer stainless-steel tube, a design model was suggested to calculate the minimum thickness and yield strength of the inner tube. Furthermore, to evaluate the ultimate bearing capacity of the CFRP-confined CFDSST stub columns, a prediction model based on the superposition principle was suggested. The calculation results of the prediction model were consistent with the test and FE results.