Abstract: A large number of experiments have proved that projectile-yarn and yarn-yarn friction have a significant effect on fabric's ability to absorb impact energy. It has been shown that projectile-yarn and yarn-yarn friction is an important factor in affecting the energy absorption properties of fabric in the spherical projectile impact on fabric. However, how the friction plays a role is not well known during flat projectile impact. In this paper, a multi-scale three-dimensional finite element model of fabric is established and combined with LS-DYNA to simulate the flat projectile impact on fabric with four edges clamped. Modeling indicated that yarn kinetic energy and yarn strain energy is the main energy absorption mechanism but sliding dissipated energy is not, however smaller friction help promote mutual movement between yarns,and increase the interaction time between projectile and fabric, which help to improve fabric's ability of energy absorption indirectly. Yarn-yarn friction plays a main role on fabric's ability of energy absorption, while projectile-yarn friction just has weak effect.

Key words: impact, fabric, friction, energy absorption