Investigation of Residual Stress Evolution Due to Cyclic Loading by Yield Surface Tracking

Additive manufacturing (AM) technologies, particularly Selective Laser Melting (SLM), enable the production of complex metallic parts directly from powder. SLM, a powder bed fusion process, builds components layer-by-layer using a focused laser source. However, the inherent thermal complexity of the process, characterized by rapid heating and cooling cycles, leads to the formation of significant residual stresses (RS). The magnitude and distribution of these stresses are highly sensitive to process parameters such as laser power, scanning speed, and scanning strategy. Within the context of AM, the most critical of these are macroscopic residual stresses, which can severely impact the structural integrity and fatigue life of as-built components. This work investigates the reduction of these stresses by applying the yield surface tracking technique, an approach traditionally used for studying plastic anisotropy, implemented on an axial-torsional testing machine.