The influence of size-dependence effect on residual stress of annular component in selective laser melting via numerical modelling and experiments

The prediction and management of residual stress in the selective laser melting (SLM) process are of paramount importance, particularly for thin-walled structures, as elevated levels of residual stress can lead to various defects, including cracks, and adversely impact the fatigue performance of components. To mitigate this issue, it is crucial to not only select appropriate process parameters but also to understand the effects of size-dependence on the evolution of residual stress. This study examines the influence of size-dependent factors, such as middle diameter, wall thickness, and part height, through a systematic methodology that incorporates numerical simulations and experimental investigations of the SLM process applied to annular components. The results indicate that an increase in part height results in a more uniform distribution of residual stress, with the stress concentration at the base being greater than that at the top. Additionally, variations in middle diameter do not significantly affect the peak value of the von Mises residual stress. As the middle diameter of the annular component increases, the residual stress at the inner wall position primarily increases, while the residual stress at the outer wall remains relatively unchanged. Moreover, the stress distribution along the side and cross-section of the annular components becomes more uniform with an increase in wall thickness. These findings offer practical guidelines for the manufacturing of metallic thin-walled annular components with a more uniform distribution of residual stress utilizing SLM technology.