A self-constraint strengthening mechanism and its application to seashells

Abstract

A self-constraint strengthening mechanism for multilayered brittle materials is proposed. The strengthening is a result of the self-constraint of the individual layers on each other, and no additional reinforcements are needed. The proposed model predicts that when individual brittle layers are stacked and properly “glued” together with a weak interphase, each layer will be ensured a minimum tensile strength, regardless of the flaw size in the individual layers. Estimation of the minimum strength using this model yields an apparently close agreement with the measured values for one type of nacreous structure reported in the literature. It is also predicted that low-strength ceramic sheets, which might be produced by some low-cost fabrication techniques, can be used to construct high strength man-made nacreous ceramics.