Effect of the inter-fiber friction on fiber damage propagation and ballistic limit of 2-D woven fabrics under a fully confined boundary condition

Abstract

This paper investigates the effect of the inter-fiber friction coefficient on fabric ballistic performance. Firstly, dynamic stress responses within a fabric due to first fiber failure are analyzed. Relations between inter-fiber friction and progressive fiber failure are assessed. Then, ballistic perforation processes of Kevlar KM2 fabrics are simulated using a fiber level micro-approach, the digital element approach (DEA). In this model, each yarn is discretized into many fibers and each fiber is divided into many rod elements. A Monte Carlo process is utilized to assign a unique strength to each element following a bimodal Weibull distribution function. DEA is used to simulate the ballistic perforation processes. A comparative investigation using a broad range of inter-fiber friction coefficients are conducted. Relations of ballistic limits and inter-fiber friction coefficients are presented. Simulation results show that ballistic limit improves as the inter-fiber friction coefficient increases up to a critical value. Beyond that point, ballistic strength decreases slightly as the inter-fiber friction coefficient increases. The inter-fiber friction also changes the ballistic perforation mechanisms.