Developing Topology Optimization with Additive Manufacturing Constraints in ANSYS®

Abstract

Topology Optimization is an effective technique to optimize structural design and to minimize waste. Additive manufacturing (AM) is potentially a great approach to fabricate the complex organic geometric features of these optimized designs. However, topology optimization without considering manufacturing constrains may result in topologies that are expensive and difficult to manufacture. In order to satisfy the constraints imposed by AM processes, this paper proposes a topology optimization methodology using the compliance minimization approach with a constraint on overhanging surfaces. Compliance of a body is approximated through a finite element analysis procedure. To constrain the gradient and converge towards a structure without overhang surfaces, a function has been developed to estimate the overhang sensitivities. The gradient of the compliance with respect to densities are penalized using the determined overhang sensitivities. To introduce a reliable platform for research, as well as solving the resulting constrained topology optimization problems, a topology optimizer has been developed in ANSYS® using ANSYS Parametric Design Language (APDL). Using a conventional topology optimization method, the results of two different case studies solved by the developed APDL program are shown. Finally, an implementation of the proposed topology optimization methodology with AM constraints is used to solve a problem. The result is a structure that does not need support material to be manufactured.