Mechanical Properties of Stainless-Steel Cables at Elevated Temperature

AbstractInvestigating the mechanical properties of stainless-steel cables at elevated temperatures is important for the fire-resistant design and fire simulation analysis of prestressed structures. Stainless steel cables comprise several stainless-steel wires encircling a core wire in different layers. The overall mechanical capacity of a stainless-steel cable is attributed to the individual properties and collaborative mechanism of the stainless-steel wires. In this study considering the number of layers of a stainless-steel wire, 42 stainless steel cables with 19, 37, and 61 wires were tested under steady-state tension at ambient and elevated temperatures ranging from 100°C to 600°C. The test results show that the cables exhibit typical nonlinear characteristics with a lower proportional limit and no obvious yield plateau. There is no obvious effect of twisting characteristics on the elastic modulus of the cables; however, the ultimate tensile strength and 0.2% proof strength decrease gradually with the increase in the number of wire layers. The reduction factors of the mechanical properties of a stainless-steel material at elevated temperatures obtained as per EN1993-1-2 were higher than those obtained in this study, particularly of the 0.2% proof strength. Equations for the elastic modulus, ultimate strength, 0.2% proof strength, and fracture strain of the cables at elevated temperatures are proposed in this paper. Furthermore, a modified two-stage Ramberg–Osgood model for stainless steel cables at ambient and elevated temperatures is proposed.