Low- and elevated-temperature constitutive model of cold-formed titanium-clad bimetallic steel sections

Abstract

An experiment was conducted to study the mechanical properties of the flat and corner portions of cold-formed TCBS sections at low and elevated temperatures. The predetermined temperatures were set at −80 °C, −40 °C, 20 °C, 200 °C, 300 °C, 400 °C, and 500 °C. The failure modes, stress-strain curves, and key mechanical parameters of TCBS flat and corner couple specimens at different temperatures were obtained based on test results. The TCBS flat and corner specimens failed in ductile mode. The stress-strain curves of the TCBS flat and corner specimens at different temperatures did not show a yield plateau. The strength properties of TCBS flat and corner specimens at low temperatures obviously increased. The strength properties of the TCBS flat and corner specimens generally decreased with increasing elevated temperature. The cold-forming process increased and decreased the strength and ductile properties of TCBS at different temperatures, respectively. Additionally, the mechanical property reduction factors of TCBS flat and corner specimens at different temperatures were compared with those of various structural steels. Moreover, the applicability of the reduction factors for yield strength and elastic modulus provided in current codes was assessed for TCBS flat and corner specimens. Furthermore, the prediction equations of mechanical parameters and constitutive models were proposed for the TCBS flat and corner couple specimens at different temperatures, which provided a basis for designing TCBS structures in low- and elevated-temperature conditions.