Study On Ballistic Limit Of Tungsten Ball Penetrating Laminated Target

Studying the layered structure design of armor materials is an important subject.The analysis of the influence of the structural characteristics,failure mode,and fragment characteristics of the multi-layer target on the penetration resistance of the target is of great significance to the improvement of armor protection.In this paper,tungsten alloy spherical fragment and Q235 steel target are selected as the research objects.The ballistic limit and the failure mode of target plate under various conditions were studied by the impact experiment of tungsten spheres on the single-layer target with a total thickness of 7.2 mm and the contact double-layer target with different thickness ratios.The experimental results show that the layered structure design of the target plate has an important influence on the ballistic limit of fragments.When the ratio of surface target thickness to total target thickness is 1 / 2,the ballistic limit of the target plate is the highest.The ballistic limit is the lowest when the thickness ratio is 1 / 4.The ballistic limit of a double-layer target with a thickness ratio of 3 / 4 is equal to that of a single-layer target;The failure mode of the target plate is closely related to its structure,thickness,and initial velocity of fragment penetration.On the basis of experiments,the theoretical model of penetration failure of contact double-layer target impacted by rigid spherical fragment is established,including the energy dissipation model of the shear plug,local deformation,overall deformation of target plate and energy dissipation formula of spherical fragment penetrating the double-layer target.The theoretical calculation is in good agreement with the experimental results.According to calculation and analysis,when the failure mode of the target plate is shear plug failure accompanied by the overall deformation,the penetration resistance of the target plate is the strongest,and with the increase of the proportion of the whole deformation energy dissipation of the target plate in the total energy dissipation of the penetrating target plate,the penetration resistance of the target plate is enhanced.In order to study the influence of the total thickness,layered design,inclination angle,and fragment diameter of the target plate on the penetration resistance of the double-layer contact plate,a numerical simulation study was conducted.The results show that when the total thickness is greater than 6 mm,the anti-penetration performance of the target can be improved by layered design,and the greater the total thickness of the target plate,the greater the impact of the layered design on the penetration resistance of the target plate;In the case of determining the total thickness of the target plate,a reasonable layered structure design can improve the penetration resistance of the target plate;when the target plate has a large inclination,the larger the inclination angle,the more suitable it is to use a single-layer target to resist spherical fragments.However,when the inclination angle is small,the target plate with layered design has more advantages in resisting spherical fragments;the layered design of the target plate has more significant resistance to small-diameter fragments.As the diameter increases,the advantage of layering decreases,until finally,it is equivalent to the resistance of a single layer target.The influence of the above factors on the penetration resistance of the double-layer target is different,but the mechanism of the influence is the same.The key factor is the different failure modes of the target plate.