Study On Fracture Mechanism And Regularity Of Plate/EFP Under Multi-point Detonation

In current combat situation,the demand for multi-mode switchable warheads is increasing day by day,and as an important part of its mechanism,the research on the formation of multi-fragment damage elements has been concerned.Using detonation wave superposition effect generated by multi-point detonation to form multiple fragments is a reliable method with strong practical characteristics and research prospects.However,due to the complexity of the detonation wave propagation process,the related research of this method still lacks certain systematic.Aiming at the lack of related research on the superposition effect of detonation wave under multi-point detonation,using metal plate and EFP structure as the effect target,the theoretical analysis,numerical calculation and experiments are carried out to study the interaction process of detonation wave,the pressure of superimposed detonation wave and the factors affecting the superposition effect.This paper provides a good theoretical basis and experimental background for the application of detonation wave superimposed in the new warhead.Mainly achieved the following results:(1)The detonation wave enhancement effect of different initiating point heights and distances are studied by using the detonation wave oblique incidence theory and LS-DYNA software to obtain the function of heights,distance and post-wave pressure.(2)The impact dynamics theory is applied to establish the analysis model of stressing plate,and the fracture failure criterion of plate is proposed.For steel,copper and aluminum and aluminum,the three-thickness plates of 3 mm,4 mm and 5 mm are numerically simulated and experiments by two-point detonation.The results show that when the speed of stressing zone is greater than the critical failure speed,the metal plate is broken.When the same material is used,the smaller the thickness is,the more likely the fracture occurs.When the thickness is the same,the aluminum is more likely to break.(3)An analysis model of double-wave point and three-point in the detonation wave collision is established.The effect of explosive types,heights,distances of detonation points and plate materials are investigated.The results show that the pressure of three-point is higher than that of double-wave point.When the ratio of the detonation point distance to the detonation height is between 5/6 and 6/5,the fracture effect is ideal(4)The simulation model of EFP structure under the condition of detonation wave superposition is established.The effects of detonation mode and explosive type on the fracture results are investigated.Studies have shown that surface detonation is superior to planar detonation.