Experimental and numerical studies on hysteretic behaviour of stainless steel welded box-section columns

Eight specimens were tested under cyclic loading to investigate hysteretic behaviour of stainless steel welded box-section columns. Failure modes, plastic development capacity, energy dissipation and ductility of the specimens were studied, and the influence of the width-to-thickness ratio as well as the axial load ratio on the hysteretic behaviour were analyzed. The test results obtained herein were used to validate finite element (FE) models, which were subsequently employed for parametric investigations to generate further data about the hysteretic behaviour of such columns over a wide range of parameters including the width-to-thickness ratio, the axial load ratio and the slenderness ratio. The FE results were utilised to assess whether codified classification limits of cross-section in 1993-1-4 +A1 (2015) are also applicable for stainless steel columns subjected to combined constant axial force and cyclic loading. The test results indicate that with larger width-to-thickness ratio the hysteresis curve becomes less plump, the ductility coefficient and the plastic development capacity are smaller; whilst effects of the slenderness ratio are not significant; the influence of the axial load ratio on the plastic development capacity is related to the width-to-thickness ratio. In addition, it is found that EN 1993-1-4 could be conservative for the classification of the stainless steel welded box-section columns class 3 and class 4 cross-sections , whereas it could be unsafe for the classification of the stainless steel welded box-section columns class 1 cross-section.