Minor-axis flexural buckling of Q1100 ultra high strength steel welded I-section columns

This paper presents an experimental and numerical investigation into the minor -axis flexural buckling behavior of Q1100 ultra high strength steel (UHSS) welded I -section columns. A total of 8 column specimens, spanning two different sections, were tested. Finite element (FE) models were developed to replicate the experimental observations, and these models were subsequently employed in a parametric investigation that encompassed a wider range of specimen geometries. Concurrently, a comprehensive evaluation of the buckling curves outlined in European, North American, Australian, and Chinese codes was performed through rigorous reliability analyses. Furthermore, this study conducted a comparative analysis between the effective width method (EWM) and the modified direct strength method (DSM) for slender cross -sections. Based on the outcomes of the reliability analyses, revised buckling curves are proposed, which are specifically aimed at enhancing the design provisions for addressing minor -axis flexural buckling in Q1100 ultra high strength steel welded I -section columns.