Adaptive stiffness in lattice metastructures through tensile-buckling inspired topology morphing

Sundararaman, Venkatesh; McHale, Ciarán; O'Donnell, Matthew P.; Chenchiah, Isaac V.; Weaver, Paul M.

Abstract

This paper explores the use of simultaneous tensile buckling of unit cells to induce a transformation in lattice topology. Under tension, unit cells undergo passive transformation from a rectangle-like to a triangle-/pentagon-like topology, with an associated change in the effective stiffness properties. This behaviour is investigated through finite element analysis and experiments, with analytical results providing insights into the observed behaviour. The analysis identifies (i) that the initial unit cell topology (rectangular) is dominated by membrane effects, (ii) the transformation phase is associated with negative stiffness, and (iii) once formed, the new topology (triangular/pentagonal) exhibits increased stiffness in both compression and tension. Finite element analysis confirms that the unit cell behaviour is also preserved in lattices. Under tension, the lattice undergoes a seven-fold increase in stiffness as it transitions from its initial to the new topology, with a regime of negative stiffness during this transformation accounting for approximately 82% of its total elastic deformation. This new approach to elastically tailor the nonlinear response of (meta-)materials/structures has the potential to contribute to the development of novel tensile energy absorbers.

• Journal Article Type: Article
• Acceptance Date: Dec 26, 2023
• Online Publication Date: Dec 29, 2023
• Publication Date: Mar 1, 2024
• Deposit Date: Jan 4, 2024
• Publicly Available Date: Jan 5, 2024
• Journal: International Journal of Solids and Structures
• Print ISSN: 0020-7683
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 289
• Article Number: 112637
• DOI: https://doi.org/10.1016/j.ijsolstr.2023.112637
• Keywords: Applied Mathematics; Mechanical Engineering; Mechanics of Materials; Condensed Matter Physics; General Materials Science; Modeling and Simulation
• Public URL: https://uwe-repository.worktribe.com/output/11548944
• Additional Information: This article is maintained by: Elsevier; Article Title: Adaptive stiffness in lattice metastructures through tensile-buckling inspired topology morphing; Journal Title: International Journal of Solids and Structures; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.ijsolstr.2023.112637; Content Type: article; Copyright: © 2023 The Author(s). Published by Elsevier Ltd.