Effects of Net and Solid Skins on Self-Supporting Lattice Structures

Multi-functional capabilities of Lattice materials allow them to be used in weight bearing applications, impact absorption and heat dissipation. Previously, the range of cellular materials was limited by constraints in traditional manufacturing technologies. This situation has been mitigated by advances in additive manufacturing (AM) techniques, which allows the manufacture of complex parts directly from three dimensional CAD models. However, other manufacturing difficulties emerge with AM techniques. Such difficulties exist with metallic components produced with selective laser melting (SLM). The need for support could compromise the quality of the lattice being built since it is difficult to remove such structures. Lattices requiring little or no support are better suited for SLM. A method was recently developed to fit such lattices to complicated three dimensional domains and consist of an approach to improve the performance of the trimmed lattices with solid and net skins. In this paper, we investigate the influence of these skins on the stiffness of Body-Centred Cubic (BCC) and Double-Gyroid (Dgyroid) lattices via finite element analysis. Including a net skin on the BCC lattice improved its stiffness as the thickness of the skin was increased. The stiffness of Dgyroid lattice was insensitive to a net skin. However, solid skins improve the performance of both lattice types.