Preparation Of Woven/Knitted Mixed Knitting And Study Of Ballistic Performance

In order to improve the ballistic performance of woven plain fabric,many researchers found that the friction between yarns is one of the factors affecting the bulletproof performance of woven plain fabric.In this research background,the plain weave mixed fabric is prepared by introducing the mixed fabric into the plain weave fabric with physical methods.The binding effect of the mixed fabric on yarns is tested by drawing experiment,the bulletproof mechanism of the mixed fabric is further studied by dynamic penetration experiment,and the penetration resistance is analyzed by comparing the finite element simulation with the real experimental data.It also provides a feasible scheme and a theoretical basis for mass production of the new type of body armor.Some progress has been made in this research,mainly in the following aspects:(1)It is possible to improve ballistic performance by introducing a mixed weave structure into plain weave fabric to limit yarn fluidity.The yarn-pulling experiment showed that the restraint between yarns was increased by 4 times by the plain/plain stitch loop structure.The bullet-penetration test showed that the bulletproof performance of the plain weave fabric was significantly better than that of the plain weave fabric,and the bulletproof limit and energy absorption of the plain weave/warp grip fabric increased by 21.7% and 50%.Images obtained from high-speed cameras show that secondary deformations are generated near the intersection of the main warp and the introduction of the mixed fabric structure,which is used to slow stress concentration and contribute to energy dissipation during ballistic events.This conclusion provides a foreshadowing for further research on the factors affecting the penetration resistance of the composite structure.(2)For the warp grip structure,the effects of the distance between the warp grip structures and the number of roots of the meridional grip structure on the energy absorption mechanism were studied.Projectile penetration experiment results show that the energy absorption effect of plain weave fabric can be improved by holding structure.In addition,narrowing the distance between holding structures can effectively increase the energy absorption effect.The number of roots of the warp holding structure and the energy absorption effect conform to the principle of decreasing marginal effect,that is,the increase of energy absorption increases first and then decreases with the increase of the number of roots of the holding structure.This conclusion provides a theoretical basis for reducing the holding distance and preparing denser mixed woven fabrics.(3)The mixed braided fabric with different surfaces was prepared.Through the breaking experiment,it was found that the fabric with different surfaces had the dynamic response speed of the plain fabric,and the breaking force was increased by 300% compared with the plain weave fabric.It is also found that the fabric has the longest displacement,which means that it has a longer protection time.Through the projectile penetration experiment,it is found that the fabric with different surface structure has better ballistic protection performance,which increases the energy absorption by 50% compared with the plain weave fabric.It has the structural stability of the plain weave fabric,the rapid diffusion of energy in the interwoven structure alleviates the stress concentration,and has the good inter-yarn restraint effect of knitted fabric,which can capture the projectile and prolong the contact time between the projectile and the fabric.This also provides the possibility for the subsequent mass production of new body armor.