Research On Strengthening Axial Damage Effectiveness Of Large Middle Caliber Ammunition

The throwing velocity of axial preformed fragments are analyzed by theoreticmodels, numerical simulations and experiments systematically. The study gives atheoretic foundation and technical support. The major study context in this paperincludes those:1) Experimental data showed that the velocities of the forward projection fragmentson the end of the cylindrical shell which was initiated at the opposite end do not match thatpredicted by the Gurney equation for plate. In this paper, Choose the symmetry structurefor studying, a new approach for addressing the velocities of fragments of this kind ofwarhead is proposed. With the theoretical analysis, the relation of parameters of explosivecharge structure, shell, and initial velocities of fragments is obtained. Experimental datashowed which is consistent with the theoretical analysis.2) During the course of axial forward projection fragments are chucked by columnarcharge. Owing to the action of lateral rarefaction, lateral leakage of detonation product is inexistence. Therefore, the effect of detonation products to projection fragments graduallydecreases along radial direction from the center of column charge. So the throwing velocityof axial projection fragments decreases gradually along radial direction. In order to studythe influence of structure parameters such as charge length/diameter ratio and the thicknessof shell to the radial distribution rule oft he axial speeds of projection fragments. Based onthe instantaneous detonation theory, and the effect of divergent detonation is alsoconsidered, the simplified model of axial projection fragments are drove by detonation ofcolumnar charge is build. The experiment results show that this simplified model is able todescribe the throwing of axial forward projection fragment that are drove by columnarcharge. It also has instructive significance to the study on damage field of axial projectionfragments ammunition.3) The throwing velocity of axial preformed fragments influenced by structuralparameters of charge such as length/diameter ratio and the thickness of shell is studied.Based on the Gurney formula hypothesis, hypothesis of two-dimensional motion ofdetonation products is proposed. The relational expression between the driving velocity ofaxial preformed fragments and charge length/diameter ratio as well as the thickness ofshell is also stated. The distribution rule of driving velocity of axial preformed fragmentson radial direction is obtained.4) Using the method of ALE arithmetic of LS-DYNA to simulation the throwingprocess of axial preformed fragments. The influence between charge structure parameters of axial preposed preformed fragment ammunition and the throwing velocity of axialpreformed fragments is studied by numeric simulation.