Modularity in Lattice structures for Circular Product Design

Abstract

The principles of repair and maintenance, reuse, and repurposing of products in a circular economy aim at further minimizing the environmental impact during the use of products before being processed for recycling. However, studies on lattice structures in various fields focus on mechanical characteristics, design, and manufacturing methods. Lattice structures are known for being lightweight, shock resistant, etc., but repair and maintenance of these lattice structures are rarely investigated. In this study, the repairability of lattice structures is explored to extend product lifespan by enabling multiple Repair & Reuse loops before the recycling loop in a circular economy. The principle of modularity was tested on lattice structures and its impact on the ease of repair, and manufacturing of large-scale lattice structures was analyzed. Modularity is a design principle of subdividing the structure into smaller parts called modules which can be independently created and assembled to form the desired structure.

A hierarchical modular approach was introduced for cuboctahedral lattice structures that proposes assembling desired large-scale structures by using modules that are themselves assembled as a result of interconnecting sub-modules. The design of these unique sub-modules, intraconnection to form modules, and interconnections within these modules involved various prototypes and simulated iterations. The final prototype was fabricated using fused deposition modeling and tested under a quasi-static compression test to validate that there is no/negligible negative impact of modularity on the lattice structure’s mechanical strength. The hierarchical modular approach and its benefits for ease of repair and manufacturing were demonstrated over a fabricated and assembled scaled-down model of an arch-type pedestrian bridge. The product journey of structures built using this approach is illustrated with a focus on ease of manufacturing and the repair & reuse loops. The study concludes with possibilities for future explorations in regards to this study and potential applications of such hierarchical modular lattice structures.