Design and additive manufacturing of cellular lattice structures

The concept of designed cellular lattice materials is motivated by the desire to put material only where it is needed for a specific application. From a mechanical engineering viewpoint, a key advantage offered by cellular materials is high strength accompanied by a relatively low mass. These materials can provide good energy absorption characteristics and good thermal and acoustic insulation properties as well. Designed cellular structures typically exhibit strong structure strength per unit weight than typical foam structures. However, due to their complexity, these structures are often difficult to generate using existing CAD packages. Furthermore, metallic additive manufacturing techniques, such as selective laser melting process which shows the great capability to fabricate strong and lightweight metallic lattice structures, are still facing certain process limitations in terms of the geometrical capability and support structure requirement for the fabrication of cellular lattice structures. This paper presents an efficient approach to generate and design periodic lattice structures and investigates the manufacturability of some selected structures using selective laser melting (SLM) process. The design of cellular structures is based on image-based algorithms to efficiently generate implicitly defined periodic lattice structure and rapidly construct volume and surface meshes. The experimental investigation on the SLM fabrication has studied the effects of unit cell type and cell sizes on the manufacturability of some typical cellular structures.