Research On Penetration Resistance Of Polyurea Coated Ultrahigh Molecular Weight Polyethylene Composite Target Plate

With the gradual enhancement of modern military power,ships are increasingly threatened in maritime warfare,and protective structures can effectively prevent the penetration of bullets,protecting personnel and equipment.With the improvement of weapon destruction ability and the requirement of ship displacement,the protective structure should meet the design requirements of lightweight and high-strength.In terms of structural protection,steel is a more traditional material that combines high strength,hardness,and density.Polyurea,as a polymer elastomer material,has excellent impact and corrosion resistance.In engineering protection,polyurea is often coated on other materials in the form of a coating to improve the dynamic fracture resistance and energy absorption ability of structures under impact loads.Fiber composite materials have low density,high specific modulus,and good tensile resistance,among which ultra-high molecular weight polyethylene materials exhibit particularly outstanding penetration resistance.In summary,the composite structure composed of polyurea,steel,and ultra-high molecular weight polyethylene can well meet the protection needs of lightweight and high-strength.This article uses LS-DYNA software to simulate and calculate the five designed configurations.Under the condition of ensuring consistent surface density,the ballistic performance of the composite target plates of the five configurations is better than that of traditional steel targets.Moreover,when the polyurea layer is layered above and below the steel plate layer and the upper layer thickness is less than the lower layer thickness,the B2 configuration has the best ballistic performance.When replacing spherical projectiles with cylindrical projectiles,simulation calculations showed that spherical projectiles of the same mass had stronger penetration ability than cylindrical projectiles,and the law of cylindrical projectiles penetrating five types of composite targets was basically consistent with that of spherical projectiles.Furthermore,further analysis was conducted on the B2 configuration with good resistance to elasticity,and the optimal thickness ratio of the polyurea coating before and after the steel plate in this configuration was studied.Through simulation calculation,it is found that when the thickness ratio of the front polyurea coating to the rear polyurea coating is1:2.91,the residual velocity of the bullet is relatively small,and the ballistic performance of the target plate is good.By increasing the bullet speed to 600m/s-700m/s for penetration simulation analysis,it can be seen from the results of the remaining velocities that there is almost no difference in the remaining velocities between each group.Observing the failure mode also indicates that the composite target plate’s ballistic performance is not fully utilized.This indicates that changing the configuration of the composite target plate becomes meaningless when the velocity of the bullet far exceeds the ballistic limit,and the ballistic performance of the target plate also decreases.Selecting a B2-4 configuration composite target plate and using ISIGHT for multiobjective optimization design,the optimal combination of 2.3mm PU,0.6mm S,and 7.2mm UHMWPE material layers was obtained.Simulation calculations were conducted to verify the results.The optimized structure showed significant improvement in ballistic performance compared to the previous optimal design configuration,meeting the expectations of lightweight and high-strength.