Research On The Structural Design And End Point Effect Of A Special Bomb

In order to meet the requirement of gun-firing low penetration projectile in special operations,the structure design and terminal effects of low penetration projectile are studied in this paper.According to the overall scheme of design specifications of low penetration bullet,we propose three different structures: pointed,blunt and head-hollow bullet,establish the models in Solid Works.Stability of bullet moving in the air is analyzed.We conduct numerical calculation on interior and exterior trajectory to determine the cartridge parameters.To qualitatively understand the terminal ballistic effects of these bullet,we conducted numerical simulation on LS-DYNA for bullet penetration into ballistic gelatin blocks and analyze the shape of cavities inside the gelatin and the velocity of bullet.We compared the computational result with experiment to verify the finite element model.It can be seen that the employed material models are sufficient for predicting the impact behaviors.We conduct similar calculation on the designed bullet and it can be seen blunt moves most stable in the gelatin block and head-hollow bullet is the most unstable one,pointed bullet has the worst killing performance and head-hollow has the best.To cut down penetration ability and increase killing performance,we conduct further development on head-hollow bullet,propose a structure called “split arrows”.We conduct research on the material of the bullet,and it turns out that when the material is lead,some bullet elements collapsed even before penetrating into the gelatin block.When the bullet is made of copper rather than lead,it brings larger cavity,and the penetration depth is more shallow than pointed and blunt bullet.The bullet fragment will form which will cause larger cavity.Bullet has better performance when the material is copper.The influences of bullet structure parameters upon terminal effects are compared and analyzed,and we get the best parameters of bullet size.The designed special cartridge and the established numerical simulation model are determined and can provide reference for the design of projectile structure and protective equipment.