Evaluating Residual Stress in 3D Printed Parts

Residual stresses play an important part in layer-by-layer fabrication process of additively manufactured parts adversely affecting the mechanical properties and dimensional accuracy of the finished parts. In this work an experimentally validated simulation model for Digital Light Processing (DLP) 3D printing was developed to investigate residual stresses and shape distortion. Hole-drilling method was used in combination with two-dimensional subset-based digital image correlation software to quantify residual stresses in the 3D printed samples. An experimentally validated Finite Element Analysis (FEA) simulation model was developed to predict residual stresses formed during the layer-by-layer deposition. A nonlinear constitutive model involving the frontal photopolymerization was established. A parametric study was carried out using the FEA based simulation model.