Numerical simulation for local buckling behaviour of HSS welded I-section columns under axial compression

In this study, the local buckling behaviour of high-strength steel (HSS) welded I-section stub columns under axial compression is investigated using finite element method, which is verified against previous experimental results. Finite element analysis is carried out to investigate the influences of the width-to-thickness ratios of plates, slenderness, and steel grade on local buckling load and ultimate load of HSS welded I-section stub columns under axial compression. The results show the width-to-thickness ratios of plates have significant influences on the stress ratios σcr/fy and σu/fy. The stress ratio σcr/fy decreases as the slenderness and steel grade increase. The influences of steel grade and the slenderness on the stress ratio σu/fy of stub columns are not obvious. Current guidance for predicting the local buckling load and ultimate load of HSS welded I-section columns is evaluated. The results show that Eurocode 3, ANSI/AISC 360-16 and GB 50017-2017 are slightly overestimated for predicting the local buckling load and ultimate load of HSS welded I-section columns. More accurate empirical models for estimating the local buckling load and ultimate load of HSS welded I-section columns are suggested. The reliability analysis of Eurocode 3, Shi et al.’s model, and the proposed models is performed according to EN 1990. •The influence of the width-to-thickness ratio of plates on the local buckling stress is significant.•Eurocode 3, ANSI/AISC 360-16 and GB 50017-2017 are slightly overestimated for the local buckling load and ultimate load.•More accurate empirical models for the local buckling load and the ultimate load are suggested.