Functional Mechanism Of Penetrator With Enhanced Lateral Effect

Penetrator with Enhanced Lateral Effect (PELE) is a kind of new kill element, which has the compositive functions of both KE and HE projectile, without dynamite and fuze. It consists of a high-density jacket, closed at its rear end and filled with a low-density material. The penetrative performance of the jacket is excellent, but that of the inner is poor. During the penetration process, the low-density filling material is squeezed between the crater bottom and the rear part of the jacket. This induces a pressure rise, dilating the surrounding jacket, and therefore enlarging the crater. As soon as the penetrator perforates the target, stresses in the jacket and the core are unloaded and the jacket is broken into pieces in radial direction. As a new conceptual kill element, PELE is mainly used in the domains of aerial defence, antimissile ammunition, striking the light-armor on the ground and offing, and destroying walls in the future urban campaign, and so on. Because of the eximious fragmental ability, it shall effectively damage the objects behind the target. Hence, the study on PELE has academic and guiding significance to overcoming the disadvantages, onefold function, of ammunitions in being, and achieving impactful damage not only in a spot but also in an area.Through theoretical analysis, numerical simulations and experimental methods, the functional mechanisms of PELE, especially the key factors that influence the lateral efficiency of PELE, are studied systemically, which would give a theoretic foundation and technical support for the design and improvement of PELE. The followings are the main contents of this dissertation:1) The velocity of debris behind the plate is researched after PELE perforated thin metal target perpendicularly. The theoretical and numerical models on the residual velocity and the radial velocity of PELE penetrating into a thin target are established and calculated. The mechanism of the production of lateral effect is illuminated in detail, and the relation between the lateral effect and the parameters of PELE is offered, and the physical picture of penetration is described. Subsequently, experiments of PELE impacting thin target are carried out, and the theoretical and experimental results are found to be in good accordance.2) The influence of the parameters about PELE on its lateral effect is investigated. The outcomes of the study indicate the following several rules. Firstly, the ratio of the compressive resistance to extension strength and density of the jacket, or Poisson's ratio and Modulus of elasticity of the filler affect the lateral effect of PELE remarkably. Secondly, when the slenderness ratio is in the range of 3～5 and inside tube radius ratio 0.5～0.7, PELE will enhance its lateral effect availably. Thirdly, with the impact velocity increasing, the residual axial velocity augments gradually, but the lateral velocity of the debris increases at first and then drops and goes up gradually afterward. However, the bigger the attacking angle is, the feebler the lateral effect is. And lastly, with the enlargement of target thickness, the lateral effect of PELE boosts up in the beginning and weakens subsequently.3) The mechanism of PELE penetrating into oblique targets is studied. Theoretical analyses on PELE penetrating into thin target and finite traget slantways are made, and the dynamic responses of targets are depicted. Besides, the pivotal factors that may work on the function are discussed. Eventually, experiments of PELE impacting oblique target are carried out, and the theoretical, the numerical simulation and experimental results agree with one another by and large.4) The process of PELE penetrating into finite concrete target is studied. On the base of the analysis about the strength during the course of the penetration, a theoretical model, which depicts the process of PELE penetrating into finite concrete target and partitions the course into three phases, is established. The shape of the perforation and the diameters of the crater entrance and exit shall be deduced from forenamed model. After that, some experiments are carried out on PELE impacting finite concrete target. The trends of the experiments results agree with that of the theoretical analysis on the whole.