Tensile stress-strain models for wire and arc additive manufacturing of carbon steels

This paper aims to investigate and develop stress-strain models for wire arc additive manufacturing (WAAM) carbon steels, providing a clear understanding of their mechanical behaviour. A comprehensive dataset comprising over 700 worldwide WAAM carbon steel tensile coupon test records from open literature was analysed. The dataset considered a variety of feedstock wires, post-treatments, surface conditions, deposition strategies, coupon extraction angles, and material thicknesses. Analysis revealed that stress-strain curves of WAAM carbon steels exhibited varying yielding responses, either discontinuous yielding with a distinct yield plateau or continuous yielding without one, depending on the feedstock wire grades and coupon extraction angles. Three tensile stress-strain models were proposed, alongside predictive expressions or recommended values for the input material parameters. These models accurately capture the stress-strain responses of WAAM carbon steels and are suitable for incorporation into analytical, numerical and design models for WAAM steel structures.