A Comprehensive Methodology for Cost Reduction in Additive Manufacturing Through Simultaneous Topology and Build Orientation Optimization

Abstract

Additive manufacturing and topology optimization technologies enable the design and fabrication of highly complex components with the potential for significant weight savings in the aerospace and automotive industries. Recent research has begun to adapt topology optimization for additive manufacturing, which has different design constraints and cost-driving factors compared to traditional manufacturing methods. However, current topology optimization methods approach cost minimization from a narrow perspective, lack realistic validation of results, and do not effectively integrate structural and orientation design. This thesis develops a novel topology and build orientation optimization approach for additive manufacturing, capable of simultaneously considering structural performance and additive manufacturing cost. A comprehensive cost metric uses four physical properties to model cost during optimization: build height, surface area, overhang area, and support structure volume. These objectives are derived as differentiable functions and rigorous sensitivity analysis is completed to enable efficient gradient-based optimization. Additionally, a novel build orientation initialization scheme prevents convergence to suboptimal solutions, avoiding the need to repeat the optimization from different starting points. The developed method is extensively verified through academic and industry-level numerical test cases, showing that the multi-objective approach generates designs that cannot be obtained with existing methods. Slicer software is used to measure material use, printing time, and post-processing metrics, demonstrating real-world cost savings of the optimized designs. The relationship between optimization objectives and slicer metrics changes significantly depending on the additive manufacturing method. This highlights the importance of customizing the objective function to effectively reduce cost, which can only be accomplished with the proposed comprehensive approach. By considering all cost objectives simultaneously, the proposed method reduces material use by 11-29% and print time by 12-54% compared to a sequential topology and build orientation optimization considering only overhang area.