Folded textured sheets

Abstract

By introducing a 'local' texture to thin-walled sheets, the 'global' mechanical properties of the sheets can be favourably modified. In this paper we explore the intriguing mechanical properties of Folded Textured Sheets, by way of two examples. The fold patterns allow the sheets to undergo large deformations, as well as change their global Gaussian curvature without stretching the material. Furthermore, both example sheets share the remarkable property that their Poisson's ratio under bending is of opposite sign to that under extension. The properties of the sheets were studied using a simple numerical model, where the folded sheets are represented by a pin-jointed framework; this captures the key deformation modes.