Topology and build orientation optimization for additive manufacturing considering build height and overhang area

Simultaneous topology and build orientation optimization approaches aim to reduce the cost of additive manufacturing components by minimizing or eliminating overhanging surfaces and support structure volume. However, current methods do not consider build height, which influences additive manufacturing printing time and can vary significantly based on orientation. This paper presents a topology and build orientation optimization approach that considers both overhanging area and build height during optimization to more accurately model additive manufacturing cost. Gradient-based optimization is performed using a novel build height calculation method and an overhang area formulation that is applicable to additive manufacturing processes that print either on a raft or directly on the build plate. A technique is proposed to automatically initialize build orientation design variables to avoid poor convergence behavior. The functionality of the approach is verified on three 3D academic models, with optimization results highlighting a clear trade-off between overhang area and build height. Slicer verification of optimized results yielded up to a 27% reduction in print time for fused deposition modeling by simultaneously considering overhang area and build height rather than only optimizing for overhang area.