Optimizing Overhang Control Using a Density Gradient Based Method - Thermal and Thermo-Fluid Applications
Saad Akhtar – Polytechnique Montréal, Canada
Overhang angle control in additive manufacturing (AM) has gained considerable interest in recent years. While effective post-processing methods exist in several AM techniques, certain processes such as Laser Powdered Bed Fusion find it impractical to add support structures to be removed later. Thus, manufacturability constraints implemented within the topology optimization framework are more appealing for such applications. While a significant recent literature tackles the manufacturability aspect in structural problems, thermal and thermofluid applications have gone largely unnoticed. This presentation demonstrates the implementation of the density gradient based method for overhang angle control in thermal and thermofluid topology optimization applications. Furthermore, the effect of build direction, overhang angle, and the overhang constraint parameters on the cost function and topologies is also examined. The overhang angle constraint is formulated using a density gradient based method integrated over the whole domain and is implemented within the National Research Council Canada’s proprietary in-house diffuse Topology Optimization solver. The results for thermal and thermofluid cases yield interesting physical insights and culminate into robust guidelines for overhang constraint parameters to achieve optimal, manufacturable topologies.