Research On Fast Algorithm In Deep/Oblique Penetration

While earth penetrator is developed more and more intelligently and effectively, the protection structures buried underground is becoming more and more complicated. Oblique penetration usually exists when striking deeply buried target, which makes the accurate prediction of the penetration depth and trace of earth penetrator a research hot-spot. Complete theoretical systems has been developed to research normal penetration, however the theoretical analysis and empirical formulas can not be perfectly applied in oblique penetration research. Thus a new theoretical system is in great need for oblique penetration research.Based on the method to describe the three-dimensional gesture of projectiles, a theo-retical system is developed to analyze the three-dimensional penetration process of ogive-nosed projectiles with considering corrections of the cavity effect, the target's free surface effect and the separation-reattachment behavior. The scaled penetration tests of steel pro-jectiles into concrete targets are designed and accomplished to provide experiment data for the verification of fast simulation program. The designed fast camera system is used to record the three-dimensional gesture of projectiles in the scaled tests.Based on isolation between the projectile and target, an analytical loading model is developed to present the interaction of the projectile and target to realize fast simu-lation. The fast simulation program is used to simulate the two-dimensional and three-dimensional penetration process of earth penetrator and the simulation results are com-pared with semi-empirical formula respectively to verify the fast simulation program. The problems that rigid projectiles penetrate into concrete targets are numerically investigated and some conclusions about oblique penetration have been acquired.Compared with the commercial numerical simulation softwares which are widely used to calculate the penetration process, the fast algorithm in this text has the advantages of less time spent and more clear physical concept and especially more significance for quick decision-making in the battlefield.