Energy dissipation in functionally two-dimensional phase transforming cellular materials

Yunlan Zhang,David Restrepo,Mirian Velay-Lizancos,Nilesh D Mankame,Pablo D Zavattieri

doi:10.1038/s41598-019-48581-8

Abstract

Phase Transforming Cellular Materials (PXCMs) are periodic cellular materials whose unit cells exhibit multiple stable or meta-stable configurations. Transitions between the various (meta-) stable configurations at the unit cell level enable these materials to exhibit reusable solid state energy dissipation. This energy dissipation arises from the storage and non-equilibrium release of strain energy accompanying the limit point traversals underlying these transitions. The material deformation is fully recoverable, and thus the material can be reused to absorb and dissipate energy multiple times. In this work, we present two designs for functionally two-dimensional PXCMs: the S-type with four axes of reflectional symmetry based on a square motif and, the T-type with six axes of symmetry based on a triangular motif. We employ experiments and simulations to understand the various mechanisms that are triggered under multiaxial loading conditions. Our numerical and experimental results indicate that these materials exhibit similar solid state energy dissipation for loads applied along the various axes of reflectional symmetry of the material. The specific energy dissipation capacity of the T-type is slightly greater and less sensitive to the loading direction than the S-type under the most of loading directions. However, both types of material are shown to be very effective in dissipating energy.

Highlights

Plastic deformation of cellular materials such as metal foams and honeycombs is commonly used for absorbing and dissipating energy because these materials can absorb large amounts of energy per unit mass[1]
They are functionally one-dimensional materials because they exhibit significant solid state energy dissipation only for loads applied along a preferred loading direction
Quasi-static, compressive load-unload tests are used to characterize the response of the S- and T- type PXCMs along the various axes of symmetry for the materials

Summary

Introduction

Plastic deformation of cellular materials such as metal foams and honeycombs is commonly used for absorbing and dissipating energy because these materials can absorb large amounts of energy per unit mass[1]. Each stable or metastable configuration defines a phase at the building blocks level, and the transitions between these building block configurations can be interpreted as phase transformations The ability of these materials to exhibit reversible solid state energy dissipation arises from the storage and subsequent non-equilibrium release of strain energy accompanying the limit point traversals underlying these transitions. Many of the PXCMs cited above are structurally two or three-dimensional materials because they can resist loads applied along arbitrary directions in the plane and space respectively. They are functionally one-dimensional materials because they exhibit significant solid state energy dissipation only for loads applied along a preferred loading direction. The second design is based on a triangular motif and has six axes of symmetry

Methods

Results

Conclusion