Experimental study of yarn friction slip and fabric shear deformation in yarn pull-out test

Single yarn pull-out test is a model experiment method to research the mechanical properties of fabric under impact. This study aims to understand the yarn pull-out mechanism and fabric shear deformation behavior of Kevlar 49 plain fabric by using the single yarn pull-out test combined with the digital image correlation method. The load-displacement curve contains typical physical phenomena such as crimp extension, crimp swap, frictional slip of yarn, and fabric deformation behavior. In the static friction stage, the pull-out load increased nonlinearly with the displacement, and the crimp extension of the pulled warp yarn occurred gradually. In the kinetic friction stage, the load decreased undulately until the warp was pulled out. Moreover, the fabric shear deformation sharply increased in the static friction stage, then decreased slowly during the kinetic friction stage. It was found that fabric shear deformation was still apparent after the yarn was completely pulled out.