Programmable Multistable Perforated Shellular

Abstract

Developing bistable metamaterials has recently offered a new design paradigm for deployable structures and reusable dampers. While most bistable mechanisms possess inclined/curved struts, a new 3D multistable shellular metamaterial is developed by introducing delicate perforations on the surface of Schwarz's Primitive shellular, integrating the unique properties of shellular materials such as high surface area, stiffness, and energy absorption with the multistability concept. Denoting the fundamental snapping part by motif, certain shellular motifs with elliptical perforations exhibit mechanical bistability. To bring the concept of multistability to a single motif, multistable shellular motifs are developed by introducing multilayer staggered perforations that form hinges and facilitate local instability. Adopting an n‐layer staggered perforation (n hinges) design leads to a maximum 2n−1 stable states within one shellular motif during loading and unloading. Three‐directional multistable shellulars are attained by extending the perforation design in three orthogonal directions. Harnessing snap‐through and snap‐back behaviors and self‐contact, the introduced multistable perforated shellulars exhibit strong rigidity both in loading and unloading, and enhanced energy dissipation. The introduced design strategy opens up new horizons for creating multidirectional multistable metamaterials with load bearing capabilities for applications in soft robotics, shape‐morphing architectures, and reusable and deployable energy absorbers/dampers.

Strut‐Based Cellular to Shellular Funicular Materials

“…[ 22 ] The shellular surface can also be perforated to impart programmable multistability and create deployable mechanical metamaterials. [ 23 ]…”

“…[22] The shellular surface can also be perforated to impart programmable multistability and create deployable mechanical metamaterials. [23] The multifunctional properties of cellular materials are mainly governed by the architectural and topological features of their nano/micro/meso-structure and the force-flow within their elements rather than merely depending on the properties of their constituent materials. [1,24] In fact, designing the architecture of cellular solids makes it possible to extend the property space of known materials, which can be visually demonstrated by 2D or 3D graphs, showing how their properties (e.g., density, Young's modulus, and yield stress) correlate with each other.…”

Minimal Surface‐Based Materials for Topological Elastic Wave Guiding

“…[ 1,2 ] For example, cellular materials have been extensively investigated due to their ability to tailor a broad range of material properties and to pursue multifunctionality. [ 3–6 ] In this context, minimal surfaces have emerged as promising platforms for continuous‐based material designs. [ 2,7–11 ] Minimal surfaces are characterized by zero mean curvature and provide an efficient tessellation of space.…”

“…[ 2,7–11 ] Minimal surfaces are characterized by zero mean curvature and provide an efficient tessellation of space. These shell‐based materials, also referred to in the literature as “shellular materials”, [ 4,5,12 ] exhibit high stiffness and strength at ultralow densities, [ 4–6 ] and ensure lower sensitivity to stress concentrations with respect to truss‐based cellular materials. The characteristics of minimal surfaces lead to materials with superior functionalities such as energy absorption, thermal management, and biomimetic designs, among others, which make them attractive solutions for applications in aerospace, civil, mechanical, and biomedical engineering.…”

“…The characteristics of minimal surfaces lead to materials with superior functionalities such as energy absorption, thermal management, and biomimetic designs, among others, which make them attractive solutions for applications in aerospace, civil, mechanical, and biomedical engineering. [ 5,6,9–11,13,14 ] While most prior investigations focus on static and strength properties, a few studies have been devoted to dynamic properties that leverage the periodic geometry of most minimal surfaces. These include for example the existence of frequency band gaps.…”