Prediction of mechanical properties of light gauge steels at elevated temperatures

Abstract

The deterioration of the mechanical properties of yield strength and modulus of elasticity is considered as the primary element affecting the performance of steel structures under fire. However, the variation of mechanical properties for light gauge and high strength steels at elevated temperatures is not known. Steels with thicknesses less than 1 mm and yield strengths greater than 500 MPa are commonly used in Australia. Therefore, an extensive experimental study into the deterioration of mechanical properties for both low and high strength light gauge steels under elevated temperatures was conducted to derive accurate reduction factors for mechanical properties in fire safety design. This study included light gauge cold-formed steels with three steel grades and six thicknesses from 0.4 to 1.2 mm. This paper presents the details of the experimental study, the results, the empirical equations for the reduction factors and a stress–strain model at elevated temperatures.