Research On The Law Of Energy Dissipation In The Process Of Helmet Bludgeoning

The behind helmet ballistic trauma increases as the protective capability of the helmets and lethal lethality of the weapon increase.In this paper,first of all,the penetration experiment of Kevlar material and resin matrix Kevlar composite laminates were done.The mechanical properties of the Kelvar material when penetrated by the bullet were revealed.The results show that whether the initial state has deformation margin or not has an important impact on the ballistic performance of the protection material.When the Kevlar layer has deformation margin,the penetration resistance of the projectile will be significantly improved.Resin-based Kevlar laminates play an important role in preventing projectile penetration,which is better than the protective material composed of Kevlar with the same thickness.And according to the experimental result,the resin matrix Kevlar composite laminate has a good anti-penetrating ability.Secondly a helmet-head-neck finite element model was established and was simulated by ls-dyna.The dynamic response characteristics of each part of the helmet-head-neck model and the energy dissipation mechanism in the situation of the penetration were acquired.The simulation results shows that the initial kinetic energy of the bullet is mostly converted to the kinetic energy and deformable energy of the helmet during the Behind Helmet Ballistic Trauma.Finally,the influence of different incident states on the initial kinetic energy dissipation mechanism of the helmet is studied by changing the initial state of the bullet.When the incident velocity was constant,a set of simulation with different incidence angle were simulated.The simulation results shows that under the same incident velocity,the change of the bullet incidence angle can affect the energy dissipation mechanism of the bullet.When the incident angle was constant,a set of simulation with different incidence velocity were done.The simulation results shows that once reach a certain velocity,the ratio of the kinetic energy transform to the kinetic energy and the internal of the helmet tends to be stable.