Model Development for Residual Stress Consideration in Design for Laser Metal 3D Printing of Maraging Steel 300

Design optimization of laser metal 3D printed structural components requires prediction of build-process induced residual stresses that vary with part geometry and affect distortion and support requirements during the build. Finite element residual stress state evaluation is not feasible within the computational constraints of iterative optimization. Alternatively, a simplified theoretical model is presented for predicting the residual stresses induced during Selective Laser Melting of maraging steel. Furthermore, a Design of Experiments (DOE) approach is implemented to verify the theoretical model and develop a response surface suitable for design optimization. The DOE uses cantilever geometry with length, thickness, and fillet radius as variables and shows overhang length to have the greatest influence on residual stresses. Geometries with high stiffness lead to lower deformations and tend to retain high stresses. The presented model can predict the trend of residual stresses for different geometries and can be used in shape optimization.