A contribution to the analysis of the intrinsic shear behavior of fabrics

Abstract

The in-plane shear behavior of textile performs is the most studied mechanical property because this mode of deformation is necessary for forming on double curvature surfaces. The resulting mechanical behavior is complex and specific considering the possibilities of relative movements between yarns and fibers. Two main tests are used: the hinged framework or ‘picture frame’ and the tensile test at 45° or ‘bias test’. Nevertheless, the results obtained by different labs using these two tests on the same fabric can be significantly different. Using a simplified analytical model of the picture frame test and a specific instrumented picture frame that enables us to track and adjust yarns tensions and to measure the strain field through optical measurements, this article analyzes and explains the origin of these discrepancies and concludes in dealing with the association between the experimental test used and the intrinsic in-plane shear behavior of a fabric.