Numerical modeling of the geometrical defects of an origami-like sandwich core

Folded cores have recently been developed for sandwich applications. The numerical determination of the out-of-plane properties of these cores requires the resolution of a stability problem. Therefore, the sensitivity of these structures to geometrical defects has to be investigated. Since the ultimate objective is to optimize the geometry of the folded cores, the defects must be defined from the folding process itself. This paper focuses on the numerical modeling of consistent geometrical defects based on a simulation of the folding process. The defects thus generated greatly influence the out-of-plane stiffness of the core because the folded edges do not remain straight. The numerical results agree well with defects observed on an actual core as well as with the global out-of-plane response. (C) 2011 Elsevier Ltd. All rights reserved.