Finite Element Modeling of Ceramic Green Part Warping Induced by Shrinkage During the Stereolithography Printing Process

The shrinkage strain, occurring upon UV curing and aging, leads to non-uniform dimensional changes that can compromise the part’s final geometry. This study investigates the deformation of green parts during the stereolithography process. Based on experimental measurements, a finite element model (FEM) is developed to account for different phenomena contributing to the structural distortion of the part, like polymerization shrinkage and the adhesion between the part and the build platform during printing. In addition, the time dependency of the degree of conversion is also considered to integrate the aging of green parts, and elastoplastic material behavior is also considered to include non-reversible deformations. This novel model makes it possible to predict stress generation during the stereolithography process and simulate part warping over time. The resulting simulations provided a numerical validation for part shapes observed experimentally, as well as insights to better understand the deformation mechanisms and optimize the dimensional fidelity of stereolithography-manufactured components.