Design And Research Of Bionic Bulletproof Insert Plate Based On Layered Structure Of Badger Tooth

Since the end of the Cold War and the beginning of the new century,local conflicts and terrorist attacks have continued to occur.With the continuous development of bullet equipment,higher requirements are also placed on personal protective equipment.As the main bulletproof structure of bulletproof vests in personal protective equipment,bulletproof inserts can be used to protect important parts of the human body and effectively reduce the damage of bullets to the human body,which has attracted the attention of military institutions all over the world.In order to adapt to the modern combat environment,body armor with better ballistic performance,lighter weight and better comfort has become the focus of research in the field of personal protection.In nature,there are many organisms that can use their own special structures to achieve good performance.Applying these structures to the design of bulletproof inserts can effectively improve the ballistic resistance of bulletproof inserts.In this paper,the teeth of a badger are used as a bionic prototype,and based on the principle of bionic design,the gradient structure and micro-topography of the teeth are applied to the design of bulletproof inserts,and a metal-encapsulated small-sized ceramic bionic insert with good ballistic resistance is designed.The main research contents and results are as follows:(1)Analysis of badger teeth characteristics.The crushing stress of the badger teeth was obtained by the universal tension press,and it was confirmed that the badger teeth had a certain impact resistance.The elastic modulus and nanohardness of badger teeth were measured by nanoindenter,and a bionic gradient model suitable for bulletproof inserts was obtained.The microscopic morphology of badger teeth was obtained by scanning electron microscopy,and the columnar structure and intrinsic pore structure of enamel were applied to the design of bionic bulletproof inserts.(2)Material selection and structural design.According to the principle of bionic design and the micro-morphology of badger teeth,the packaged small-sized ceramic target plate was innovatively designed;based on the principle of acoustic impedance and cost-effectiveness,Si C ceramic was finally selected as the small-sized ceramic material,titanium alloy as the metal frame material,and back plate material.It is an ultra-molecular weight polyethylene fiber material.The Johnson-Cook,Johnson-Holmquist? and EDC constitutive models were used to describe metal materials,ceramic materials and fiber composite materials by LS-DYNA software,and the validity of the finite element method for the simulation of the penetration process was verified.(3)Analysis of protection performance of bionic insert board.Ls-dyna finite element software was used to penetrate the bionic target plate with 7.62 mm steel core projectile based on Lagrange algorithm.According to the numerical simulation results,the metal frame can prevent the crack propagation in the ceramic layer,reduce the damaged area of the target plate,and improve the protection performance of the bionic insert plate.The influences of ceramic shape,ceramic width,ceramic spacing,backplane thickness and location of the bullet on the bullet-proof property of the bionic insert plate were analyzed by residual velocity of projectile,penetration process,ceramic damage cloud map,equivalent stress cloud of titanium alloy frame and displacement cloud of backplane fiber.Finally,it is determined that the ceramic shape is cylindrical,the diameter of single-layer ceramic is 4 mm,the ceramic spacing is 1 mm,and the fiber thickness of backplane is 10 mm.When the impact point is the center ceramic eccentricity position,it can effectively resist the penetration of 7.62 mm steel core projectile at 840 m/s speed.