Finite Element Modeling of Crumpling of Metallic Thin Foil

Abstract

Crumpled metallic thin foils are very promising as weight‐saving and energy‐absorption materials that can easily be fabricated. To achieve practical industrial applications, it is necessary to improve the understanding of the process of crumpling and the mechanical behavior of crumpled materials considering their complex internal structures. Herein, two possible strategies for computational simulations of crumpled material under closed‐die compression are presented for the first time. The first one entails computations performed at the scale of the foil (direct method), while the second one considers the structure as a continuum with porosity. The analysis performed shows that the continuum‐based approach is more suitable for representing the macroscopic mechanical behavior of crumpled materials with the relative densities ranging from 2% to 40%. An additional benefit is the low computational cost and high efficacy of the porous continuum approach. However, the direct method is shown to be the preferable computational tool when the internal structural patterns changes need to be adequately reproduced, e.g., for a better prediction of the mechanical response under complex loading conditions.