Shear strength of fibrous sheets: An experimental investigation

This study of the shear strength of fibrous sheets first measures the in-plane shear strengths of various samples, including woven and nonwoven fabrics and paper, using a custom-made apparatus attached to an Instron tester. The structure of the apparatus and the measurement procedures are introduced in this article. The tested shear strength values are then compared with theoretical predictions from an earlier work. Discrepancies and possible causes are analyzed. Load-elongation curves for both tensile and shear are compared for individual fabrics and between fabrics. The relationship between the anisotropy of fabric tensile strength and the ratio of tested and predicted shear strength is explored. Also, the effect of fiber movement during textile deformation is examined. Finally, the original Tsai-Wu theory used for shear strength prediction of anisotropic materials is modified for application to the fibrous sheets, and the new predictions are provided for comparison.