Topology and Printing Orientation Optimization of Orthotropic Material for Additive Manufacturing

Mechanical properties of 3d printed polymers have witnessed remarkable improvements as a result of optimization in topology and raster orientation. This study proposes and evaluates a strategy to deal with stiffness maximization of structures in elastic region subjected to global volume and compliance constraints. This work also presents a unique approach to dealing with local constraints, specifically stresses along and perpendicular to the fibers of the printed structures (principal material axes). A modified SIMP (modified solid isotropic material with penalization) method is used with the method of moving asymptotes (MMA) as the optimizer. A detailed description of the formulation and sensitivity analysis are discussed. 2D structures are then analyzed in the numerical examples section. The method can also be used for 3D structures, as the formulation derivation is general. Results show that this method is effective for producing manufacturable 3D printed structures that avoid stress concentrations.