Investigating Simulation Approaches for Distortion in Thin-Walled Components During the Selective Laser Melting Process

Abstract

The inherent challenge of part distortion during the Selective Laser Melting (SLM) process remains a significant concern, especially for thin-walled structures. Various simulation strategies predict part distortion before 3D printing, saving material, time and cost. This work focuses on simulation methodologies for predicting distortion in thin-walled components. We used single-layer, multi-track meso-scale simulation, incorporating Gaussian heat flux and accounting for phase and material property changes, to predict inherent strains. We compared distortion predictions for square, cylindrical, and single-walled structures using four approaches: isotropic yield strain, thermal shrinkage strain, experimental strain, and meso-scale-obtained strains. The results showed that isotropic yield strain, while tending to overestimate distortion, was suitable for generating qualitative distortion profiles for symmetric thin-walled structures such as single-walled, square, and cylindrical ones. It also proved valuable for comparative studies in part-level simulation with distinct geometrical parameters. For square-walled structures, width was identified as the primary driver of distortion, with increasing width leading to a nearly linear increase in distortion. Cylindrical thin-walled structures exhibited lower deformation compared to square sections. Increasing diameter and height increased distortion, while distortion slightly decreased when thickness increased from 0.5 to 2 mm. In single-walled structures, wall width was the dominant factor affecting distortion.