Cyclic Shear Test Under Biaxial Loading in Bias Direction: Application to Coated Woven Fabrics
摘要
Coated woven materials are developing for a wide range of applications, but their mechanical behavior is still poorly describing and their shear properties poorly understood. This paper deals with the experimental study of the shear behavior of coated woven materials under cyclic biaxial loading. The aim is to implement the biaxial test in the bias direction, in order to study the shear properties of coated woven materials. We used cruciform specimens with three incisions in each arm. Strain homogeneity in the central part of this specimen had validated by measurements of the strain field, using Stereo Digital Image Correlation (SDIC). Moreover, we carried out a local strain measurements in the useful part of the specimen, using a CCD camera. This enabled us to characterize the variation in the angle between warp and weft, as well as to measure deformation along the warp and weft. These results show a coupling between cyclic shear effects and deformation in both warp and weft directions. Indeed, they reveal an original phenomenon of cyclic ratcheting strain in both warp and weft directions. This phenomenon, which to our knowledge, has not been observed before in woven materials, manifests itself in a systematic increase in strain values in both warp and weft directions with each shear cycle.