Micromechanism of deformation in EMC laminates

Elastic memory composites (EMCs) are receiving more attention in deployable spacecraft industry because they can realize much higher packaging strains without damage and automatically recover to their original shapes when subjected to a specific thermomechanical cycle. Experimental researches have revealed that microbuckling and post-microbuckling responses of compressed fibers in the soft matrix are the primary deformation mechanism of EMCs to realize higher packaging strains than traditional composites. However, a thorough understanding about the deformation mechanism of EMCs has not yet been achieved. This paper presents a new shear/tension microbuckling solution to study the deformation and failure process of EMC laminates under bending. The microbuckling wavelength, critical compressive stress and strain for carbon-fiber/resin EMC laminates are calculated, and different theoretical solutions are compared with the experimental observation. Moreover, the possible failure modes of this type of materials are discussed as well.