Behaviour and design of square steel tubular slender columns at low temperatures

Abstract

The paper reported an experimental and numerical study on the low-temperature compression behaviour of square steel tube slender columns (SSTSCs). Thirteen SSTSCs were tested at low temperatures of 20, −30, −60, and − 80 °C. The SSTSCs with different slenderness ratios eventually failed in global buckling. The experimental results indicated that reducing the temperature from 20 °C to −80 °C improved the ultimate compressive capacity (P_uT) of SSTSCs by over 10 %, but had marginal influence on the ductility (DI) and failure modes. The increasing slenderness ratio compromised the compression behaviours of SSTSCs with the reduced P_uT and DI ratios. The established finite element models (FEMs) were validated by 13 SSTSCs test results at low temperatures. After validations, additional 104 FE results were obtained by a more extensive parametric study, e.g., low temperatures, slenderness ratios and width-to-thickness radios. Moreover, the applicability of the design curves in Eurocode 3, AISC 360–16 and GB50017 for SSTSC prediction was checked by these experimental and FE results, with prediction-to-test ratios of 0.90, 0.99 and 0.88, respectively. Validations indicated that three different codes could provide reliable and slightly conservative predictions on the P_uT under low-temperature compression