Exploring Damage in Mechanical Metamaterials

Since the advent of composite materials, engineers have continuously sought ways to enhance mechanical performance and damage tolerances through the combination of different material compositions. Recently, this pursuit has intersected with the fields of mechanical metamaterials and traditional fracture mechanics. In this talk, we will explore the use of mechanical metamaterials as bonding interfaces, with the potential to replace bulk adhesives. We will emphasize the need for new testing methods within a fracture mechanics framework, focusing on critical design parameters such as stretching, bending, and unit cell dimensions [1]. Our investigation into the toughness of these architected interfaces addresses their structural integrity and the propagation of damage. Through theoretical and numerical models, we predict compliance and failure loads, demonstrating that specific cell geometries can effectively control damage and enhance failure loads [2]. Furthermore, we employ modeling with micropolar elasticity to gain deeper insights into these complex materials. In a proposal of an enhanced elastic foundation theory, validated via double cantilever beam configurations, we incorporate micropolar behavior to clarify size effects [3]. In addition, we examine damage mechanics in mechanically stable Maxwell lattices, applying topological principles to regulate fracture in kagome lattices. By representing these lattices as networks of harmonic springs, we demonstrate that topological principles can effectively manage crack propagation. This multifaceted approach provides a comprehensive understanding of how mechanical metamaterials can revolutionize bonding interfaces and broader material applications.

Keywords: Mechanical metamaterials; Bonding; Adhesive; Homogenization; Fracture;
Maxwell lattices

References

[1] A. E. F. Athanasiadis, M. A. Dias, M. K. Budzik, “Can confined mechanical metamate-
rials replace adhesives?”, Extreme Mechanics Letters 48, 101411 (2021).

[2] M. L.S. Hedvard, M. A. Dias, M. K. Budzik, “Toughening mechanisms and damage
propagation in Architected-Interfaces,” International Journal of Solids and Structures,
288, 112600 (2024).

[3] A. E.F. Athanasiadis, M. K. Budzik, D. Fernando, M. A. Dias, “On micropolar elastic
foundations,” European Journal of Mechanics – A/Solids, 105, 105277 (2024).