Kinetic Energy Warhead Concrete Target Invasion Burst Effect Study

The penetration and blasting damage for anti-hard-target warhead have become a hot topic in development of conventional weapon and design of defense engineering. It is of significant importance for development of new-concept warhead and design of defense engineering, including the studies of penetration efficiency and blasting-damage evaluation for high-speed deep-penetration anti-hard-target warhead and fiber reinforced composite one.The phenomena that may occur during the high-speed or mid-speed penetration of new-concept warhead penetrating concrete is synthetically analyzed, including the damage of the target, the efficiency of the loaded explosives, the quasi-static failure of concrete target and the efficiency of the fiber-reinforced composite warhead penetrating the concrete structure by theoretical analysis, numerical simulation and experimental research. The results obtained are damage characteristics of concrete target, the influence of the warhead shell for efficiency of blasting damage and the failure rules of concrete target by combination of penetration and blasting damage. And the details are listed below.(1) The concepts are advanced for high-speed deep-penetration anti-hard-target warhead and fiber reinforced high-backfill ratio one based on the present anti-hard-target warhead problems and the military need. A new constitutive model for concrete under penetration and explosion is established on foundation of synthetically analysis of present dynamic constitutive models of concrete. The numerical simulations, the high-speed deep-penetration warhead and the fiber reinforced one penetrating concrete target, are run by nonlinear dynamic program and the damage effects of warhead/target are analyzed. The penetration abilities of two new-concept warheads are verified by numerical simulation.(2) Two new-type sample projectiles, taper groove anti-hard-target warhead and fiber reinforced one, are designed based on theoretical analysis and numerical simulation. The sample projectile design breaks through conventional modes of warhead, i.e., cylinder shape and whole metal shell. It is studied experimentally on high-speed anti-hard-target warhead and fiber reinforced one penetrating concrete target at high speed or mid speed. The projectile is fired by artillery or sub-caliber propelling technique and the impact velocities obtained from tests are in the range of 300-500 m/s or nearly up to 1200 m/s. The deformation and failure characteristics of target are analyzed in combination of the numerical simulation results. Which confirms the feasibility of the concept of two new-type warhead and their penetration performances.(3) Deduce theoretical formulae, including the formula for the explosion of charge with shell in air and the one for damage area and energy distribution of charge with shell blasting in concrete target, in combination of the stress wave theory, energy principle and the blasting physical and mechanical behavior of charge with shell. Analysis indicates that the application domain for the theory formulae is more wide and the predictions of these theoretical formulae agree well with the results of tests and numerical simulations.(4) The comparison of three types of charges, i.e., the naked charge, the charge with composite material shell and the one with steel shell, are conducted based on theoretical analysis focusing on their explosion efficiencies in air, their drive abilities of the targets and the damage effects of concrete targets. Acquire the common sense such as the peak overpressure distribution and the damage effect of the blast fragments which may destroy the surrounding targets, the influence of the backfill ratio and the shell material of charge to the damage of concrete target and its blast tunish cavity.(5) Based on theoretical analysis and experimental results, the finite difference software AUTODYN is used for numerical simulation of the blast effect of three types of charges, i.e., the naked charge, the charge with composite material shell and the one with steel shell, exploding in concrete targets. And the simulation results are agreed with the theoretical analyses and the experimental results.(6) The dimensionless factor, i.e., the crush function,is deduced considering the influence of the non-ideal explosion and penetration damage, which gives more accurate prediction of the size of the crush area in target by explosion. The prediction of the theoretical formula is agreed with the numerical simulation result during the whole process of the fiber reinforced anti-hard-target warhead penetrating into concrete target.Finally, summarize this paper, listing some important conclusions deduced from this paper and several suggestions for future research in the penetration and blasting effect of target/warhead.It is universal for the achievements of this paper, which establishes the foundation of the further engineering application and evaluation of the penetration-blast damage effect for the fiber reinforced high-backfill ratio anti-hard-target warhead and high-speed deep-penetration one. Furthermore, it is of great importance for finding out the main factors and rules of the penetration efficiency verification, the influence of warhead shell for blast damage effect. That is to say that this paper is helpful in application.