Effect Of Interfacial Friction On Impact Energy Absorption Capacity Of High-strength Fabric Structure

The bulletproof property of body armor made of fiber-reinforced compositehas always been a hot topic of research in the field of military. The fabric madeof the light-weight and high-strength fiber-reinforced composite also has thesame properties, so it is widely used in body armor and other fields that easilyoccurs impacts. In the factors that influence ballistic impact property of bodyarmor，interfacial friction is one of the important factors that can’t be ignored. Inthis paper,interfacial friction was explored.In this thesis, the ballistic impact process of a high-strength plain-weavefabric with various friction conditions were simulated by using LS-DYNA finiteelement analysis models; the effect and its mechanism of interfacial friction onimpact energy absorption of the high-strength fabric were investigated throughcomparison of residual velocity of projectile, energy transfer within the impactsystem, stress distribution and deformation of the fabric. Results show thatinterfacial friction is helpful to improve impact energy absorption of fabric;fabric can absorb more energy with increased interfacial friction. Interfacial friction not only induce frictional sliding dissipated energy but also improveimpact energy absorption of fabric through increasing yarn strain energy andyarn kinetic energy. With increased interface friction, the frictional slidingdissipated energy does not change significantly, however, yarn strain energy andyarn kinetic energy increase substantially with increased interfacial friction.Mechanism of the effect of interface friction is that yarn-yarn friction preventlateral movement of yarns, more yarns are therefore involved in the impactprocess and impact energy absorption of fabric is increased; projectile-fabricfriction prevent lateral movement of yarns that directly contact with projectile, itdistribute larger stress in the peripheral of the contact zone and thereby delayyarn failure and increase fabric energy absorption; the friction between fabriclayers prevent relative movement between yarns of adjacent layers, it reducelateral movement of the yarns in the contact zone and increase energy absorptionof fabric. The factors of number of layers and the size of fabric are alsoinvestigated in this thesis. Results show that combined effect of interfacialfriction is not simple summation of the effect of each type of friction that workindividually; regardless of fabric size, the effect of interfacial friction on impactenergy absorption of fabric are the same. Based on the deep study of interfacefriction that affect the ballistic impact property of high-strength fabric, it wasachieved how the yarn-yarn friction, layer-layer friction and projectile-fabricfriction affect ballistic impact property of body armor during impact. Theresearch provides an important basis to promote bulletproof property of body armor and has important significance to the optimization of body armorprotection ability.