Measurements of shear characteristics of textile composites

The paper is devoted to experimental study of shear strength and shear modulus of three types of 3D textile composites based on different reinforcing fibres and matrices and made by various technologies, as well as 2D glass fibre/epoxy plastic (GFRP) with lay-up of (±45°). Correct measurement of shear properties of 3D textile composites is a complex problem due to the lack of the planes of weak shear strength and high structural heterogeneity of the materials. These features of 3D textile composites make it problematic to use a set of shear tests developed for unidirectional and laminated composites and forced to call a special attention to the shear tests of isotropic materials. Shear properties of the composites studied are measured by nine different shear tests, including Iosipescu method and its modification, Asymmetric Four-Point Bending (AFPB). It was done by a comparative analysis and evaluation of suitability of the shear tests applied for 3D textile composites and 2D GFRP/Epoxy with lay-up of (±45°).