LAUSR

Abstract A new theoretical method is proposed to predict the elastoplastic behavior of three ductile metallic materials, including mild steel Q235, high strength low alloy steel HSLA350, and aluminum alloy AL6061. Using this method, only basic experimental parameters are needed for estimating the pre-necking true stress–strain relation. The evolution of the neck profile of a cylindrical tensile specimen is derived based on experimental measurements. The pre-necking model is able to describe the Luders deformation phenomenon with great precision. It can also provide precise predictions for the pre-necking behavior of structural steels S275, S355, S460, and S690. In addition, the new post-necking model can accurately determine the equivalent stress-strain relation. The complicated analysis of the stress correction factor is avoided in this method. Comparison between our new method and the existing ones is carried out. The accuracy of our prediction is higher than existing methods, e.g., the Hollomon method, the Ludwick method, and the weighted average method (WAM). This work not only provides new insights into the elastoplasticity and fracture of metals, but also holds promise in the design of metal forming.