Shear Properties of PVDF-Coated Fabrics under Multicyclic Biaxial Bias Extension

Abstract

In this study, the multicyclic biaxial bias extension test using cruciform specimens with 45°-oriented fibers was carried on an advanced biaxial tensile tester, and three different shear loading histories (SLHs) were utilized to estimate shear properties of polyvinylidene fluoride (PVDF)–coated fabrics. The distribution of shear strain in the area of interest was homogeneous according to the results of digital image correlation. The experimental results showed that shear stiffness of coated fabrics decreased from 11.4 to 3.9 kN/m with the improvement of maximum shear stress. The normal stress in the warp and filling directions enhanced the shear stiffness according to the comparison among three shear loading histories. The reduction of residual shear strain indicated that the zero-shear-stress condition contributed to shear deformation recovery. Finally, the deformation mechanism of biaxial bias extension was considered on the basis of experimental observation. In general, this study proposed a specific test method to understand shear properties of coated fabrics used in membrane structures.