A Model for Analyzing Single Yarn Pull-out Behavior Considering the Contact State of Fabric Interface

A single yarn pull-out model test on Kevlar 49 plain weave fabric was conducted using three yarn pull-out speeds of 100, 500, and 1000 mm/min. The interface contact state during the yarn pull-out process was analyzed. An energy absorption model was proposed that considered the convex–convex and concave–concave contact states of the tensioned yarn interface during the yarn pull-out process. The specific dividing points between static friction and dynamic friction before and after the yarn slips were defined. The peak and trough load values of the load–displacement curve in the dynamic friction stage were extracted. The convex–convex and concave–concave contact states of the interface during the yarn pull-out process were inverted. In addition, the interface shear stress conditions, and linear stress transfer models were established to calculate the strain energy and frictional energy consumption during the yarn pull-out process. The mechanical response state of the yarn pull out was predicted, and the results showed that the friction properties of the fabric interface were not sensitive to the loading rate. The theoretical model was accurate for the energy absorption during the yarn pull-out process. The mechanical response to the load displacement under the three yarn pull-out speeds showed good predictability.