Solid mechanics based design and optimization for support structure generation in stereolithography based additive manufacturing

Support structures are typically required to hold parts in place in various additive manufacturing processes. Design of support structure includes identifying both anchor locations and geometries. Extensive work has been done to optimize the anchor locations to reliably keep part in position, and minimize the contacting area as well as the total volume of the support structures. However, relatively few studies have been focused on the mechanical property analysis of the structure. In this paper, we proposed a novel design optimization method to identify the anchor geometry based on solid mechanics theory. Finite element analysis method is utilized to study the stress distribution on both the support structure and main part. Particle Swarm Optimization (PSO) algorithm with a novel constraining handling strategy is employed to optimize the design model. A gradient descent local search algorithm is utilized to quickly locate the global solution in the vicinity explored by PSO. The developed optimization framework is deployed on a bottom-up projection based Stereolithography process. The experimental results show that the optimized design can efficiently reduce the material used on support structure and marks left on the part.