Broken Hole - With Embedded Tandem Warhead

Tandem shape charge --- embedding warhead is a new type of warhead, which is consisted of forward shaped charge and backward penetrator. Firstly, the jetting projectile formed by the shaped charge penetrated the target, then the backward penetrator embedded the perforated target by the kinetic energy, thus the damage and blockade effect of the warhead was realized. In this thesis, Tandem shape charge --- embedding warhead's embedded process and mechanism was studied by theoretical analysis, numerical simulation and experimental study. The fracture analysis model about the penetrator embedding perforated target was established, and the factors which affected the fracture failure model were analyzed. The result of this thesis would provide valuable theoretical basis and technical reference for the Tandem shape charge --- embedding warhead's design and improvement. The followings are the main contents of this dissertation:1) The penetration process of the jetting projectile charge towards the target was firstly studied. Factors influenced the penetrate effect was analyzed. The result indicated:(a) Diameter of perforated hole caused by forward shaped charge was around 20-23mm (60mm steel plate), the diameter of the entrance hole was slightly smaller than the oulet hole; (b) As the liner thickness --- charge diameter ratioδ/D increased, the aspect ratio of the jetting projectile charge first increased and then decreased; (c) As liner curvature radius --- charge diameter ratio R/D increased, the aspect ratio of the jetting projectile charge decreased, when R/D≥0.833, the jetting projectile would fail to form.2) Action process of the tadem warhead towards the target was studied, the forward shaped charge's detonation effect on the backward penetrator was analyzed. The simulation model was set up respectively, result of which indicated that forward charge affected the backward penetrator greatly. While with the increase of baffle plate's thickness, the negative influence was decreased, when the thickness reached 30mm, the deformation and velocity drop of the penetrator was relatively minimum. With the initial velocity of the penetrator increased, the deformation was insignificant while the velocity drop increased accordingly. And if axis of the backward penetrator was not coincided with the forward shaped charge, the penetrator would possess the angle of attack during the embedding process.3) Embedding process of the backward penetrator was studied, and factors which affected the embedding were analyzed. The result indicated:(a) With the initial velocity of the penetrator increased, the embedding depth increased, and the appropriate initial velocity would be 200m/s-350m/s; (b) When the initial velocity was a constant, the embedding depth increased with the pre-proforated hole's diameter dimension, however, the 20-26mm diameter proved appropriate.4) Fracture failure analysis model about the penetrator embedding pre-perforated target vertically is established, and the penetrator's threshold velocity when the failure occurred was obtained, numerical simulation and experiment were both adopted to validate the theoretical result. Further research indicated the threshold velocity increases along with the penetrator's material yield stress, tangent modulus and failure strain, inversely along with the material density.