Mesures de champs pour des essais de cisaillement sur des renforts tissés

Abstract

The mechanical behaviour of dry woven fabrics as composite reinforcements is investigated using optical strain measurements during pure shear tests performed on a picture frame device. This optical measurement technique has many advantages, including the absence of contact with the sample. A change in lens allows measurements at different scales, from a whole sample (macroscopic measurement), to a few unit patterns only (mesoscopic measurement). On top of that, the out of plane displacement may be obtained by a stereoscopic method, using two symmetric points of view. Thus, detailed description of a pure shear test may be conducted, leading us to explain the forming of wrinkles within the woven sample, concluding the test.