Topology Optimization and Additive Manufacturing of Lower Arm of a Robotic Manipulator

In this paper, topology optimization was implemented in the design phase to achieve a lightweight and structurally sound design of a robotic part while taking into account manufacturing constraints. Three different Computer-Aided Engineering (CAE) software packages were selected: SolidWorks-TOSCA, HyperWorks-OPTSTRUCT and Abaqus-TOSCA. The topology optimization was performed using the most popular numerical method, namely Solid Isotropic Material with Penalization (SIMP). A qualitative analysis was conducted on the different software tools by comparing their execution time, ease of use and optimization results. The problem of reducing mass by 80% and maximizing the stiffness of the lower arm of a robotic manipulator, while being subject to a relevant loading force, boundary conditions and manufacturing constraints was studied. A well-known case study that is a rudimentary prismatic solid was considered to define the user-specified design space. Each optimized design was fitted using GeoMagic Design X software that allows to create fully parametric CAD solids and free-form surfaces from polygon mesh data resulted after optimization. Three parametric 3D models were then generated. Finally, three CAD models were validated through finite element analysis. One of them was selected and its physical prototype was produced by additive manufacturing. As perspective, it will be experimentally controlled by 3D scan.