Compressive behaviour of high-strength steel cross-sections

The recent increase in the use of high-strength steels (HSSs) in modern engineering practice necessitates a deeper understanding of their structural response. Given that HSS design specifications are largely based on a limited number of test data and assumed analogies with mild steel, their applicability to HSS sections needs to be assessed. In the work reported in this paper, finite-element models were developed and validated against experimental data of hot-finished S460 and S690 grade steel stub columns. Parametric studies were conducted to generate a large volume of structural performance data over a wide range of cross-section slenderness values and aspect ratios. On the basis of the results, the suitability of the Eurocode 3 (EC3) class 3 slenderness limit and the effective width equations for HSS sections were assessed. Aiming to account for element interaction effects, which are not considered in EC3, an effective cross-section method applicable to HSS slender sections was developed. Finally, the continuous-strength method was extended to stocky S460 sections, for which overly conservative strength predictions were observed. The reliability of the proposed design methods was verified according to annex D of the Eurocode structural design basis (EN 1990).