Strengthening of circular austenitic stainless steel tubular columns with CFRP under eccentric loading: Experimental and numerical investigations

This study investigates the structural behavior of CFRP-wrapped circular stainless-steel tubular (CSST) columns subjected to combined axial compression and bending loads. Eighteen cold-formed stainless steel tubular specimens with varying diameter-to-thickness ratios, CFRP wrapping configurations, and load eccentricities were tested experimentally. Results reveal that CFRP wrapping significantly enhances the load-bearing capacity and ductility of CSST columns by mitigating local buckling and delaying failure. Finite element models were developed and validated using ABAQUS software to complement experimental findings. A comprehensive parametric study explored additional factors influencing structural behavior. Based on the combined experimental and numerical results, a design model was proposed by incorporating the effect of CFRP wrapping into the Continuous Strength Method (CSM) framework. The proposed model demonstrated high accuracy in predicting failure loads and moments, offering a practical approach for the structural design of the strengthened CSST. This work advances the application of CFRP in enhancing the performance of structural stainless-steel components.