Geometric modeling of lattice structures for additive manufacturing

Purpose: In this paper a consistent approach to geometric modeling of optimized lattice structures for additive manufacturing technologies is proposed. Design methodology: The proposed method applies subdivision surfaces schemes to an automatically defined initial mesh model of an arbitrarily complex lattice structure. The approach has been developed for cubic cells. Considering different aspects, five subdivision schemes have been studied: Mid-Edge, an original scheme proposed by the authors, Doo-Sabin, Catmull-Clark and Bi-Quartic. A generalization to other types of cell has also been proposed. Findings: The proposed approach allows to obtain consistent and smooth geometric models of optimized lattice structures, overcoming critical issues on complex models highlighted in literature, such as scalability, robustness and automation. Moreover, no sharp edge is obtained and consequently, stress concentration is reduced, improving static and fatigue resistance of the whole structure. Originality/value: An original and robust method for modeling optimized lattice structures was proposed, allowing to obtain mesh models suitable for additive manufacturing technologies. The method opens new perspectives in the development of specific CAD tools for additive manufacturing, based on mesh modeling and surface subdivision. These approaches as well as slicing tools are suitable for parallel computation and therefore allows the implementation of algorithms dedicated to graphics cards.