Three dimensional topology optimization with orthotropic material orientation design for additive manufacturing structures.

Products produced with Additive Manufacturing often have anisotropic microstructures that form material layers are added during processing. Carbon fiber filled polymer deposited in beads with the Fused Filament Fabrication (FFF) process, for example, has been shown to have a highly anisotropic material response. This thesis considers the anisotropic behavior of FFF structures and presents a three dimensional topology optimization method that computes the best anisotropic material distribution and direction for minimum compliance of statically loaded AM structure. The optimization method is applied to single loaded problem, multiple loaded problem, and structures with regions of prescribed solid or void. Results show that printing the structures in different planes yields different minimum compliance of statically loaded AM structure. The opitmization method is applied to single loaded problem, and structures with regions of prescribed solid or void. Results show that printing the structures in different planes yields different minimum compliance, and that the lowest overall compliance is achieved when the applied load vector is parallel to the plan of material orientation. Furthermore, the preferred material orientation generally follows the outer contour of the dense material region for each layer.