Integration of Machine Tool Accessibility of Support Structures with Topology Optimization for Additive Manufacturing

Accessibility by machine tools for the removability of support structures is a very important aspect to consider when deciding the part design and build orientation of a part in a metal-additive manufacturing process. In this paper, machine tool accessibility of the support structures is considered in a compliance minimization topology optimization model. This was achieved by including a new support accessibility filter in addition to a previously existing support structure optimization filter within a classic density-based compliance minimization model. The design of the part is optimized so that the support structures built for the part are completely accessible in a pre-defined direction mimicking a ram-type EDM tool for support-structure removal. To date, the application of support accessibility has not been addressed in previous publications related to the inclusion of design for additive manufacturing constraints within topology optimization. With this new addition, we were able to achieve high stiffness part designs with fully accessible support structures.