Influence Of Manufacturing Deviation On Jet Forming And Armor Breaking Performance Of Shaped Charge

Shaped charge has been widely used in military fields and engineering construction due to its strong directionality and excellent penetration performance,such as anti-tank shaped charge technology,geotechnical engineering excavation technology,petroleum perforating charge technology and linear cutting shaped charge technology.For the rotationally symmetric shaped charge structure,strict axial symmetry is an important guarantee for its stable penetration characteristics,but few studies take the deviation factors generated in the manufacturing process into account,which restricts the development of shaped charge technology.The research on the influence of manufacturing deviation on the jet forming and penetration performance of shaped charge is of great significance to the development of shaped charge and its damage effect evaluation.This paper focuses on the subject of the influence of macroscopic manufacturing deviation on the jet forming and penetration performance of shaped charge.Taking an individual armor-breaking warhead as the research object,a comprehensive analysis of the jet forming and penetration performance of shaped charge under a single macroscopic manufacturing deviation(initiation position eccentricity,liner offset,liner deflection angle)was carried out using the method of combining experimental research,numerical simulation and theoretical analysis.The variation laws of detonation wave shape,asymmetric crushing degree of shaped charge liner,jet shape and lateral velocity,and penetration characteristics are obtained.The influence mechanism of macroscopic manufacturing deviation on jet forming and penetration process of shaped charge is revealed.The correlation between the non-ideal jet and the penetration performance is established.Through orthogonal experimental design and variance analysis,the significant differences and primary and secondary relationships of manufacturing deviations were revealed.Specific contents include the following:(1)In order to sum up the factors affecting the penetration efficiency of shaped charge and relevant research results.Based on a large number of literature research,the mechanism and influence law of shaped charge on the penetration efficiency of shaped charge are expounded from four aspects:charge,shaped charge,detonation wave and asymmetric factors.It also looks forward to some hot research issues in the future,which has certain reference value for researchers engaged in relevant fields.(2)Based on the theoretical analysis and the numerical simulation method verified by experiments,the numerical simulation research on the jet forming and penetration process of shaped charge is carried out when the eccentricity of the initiation position is 0～0.05D_k.The variation rules of jet forming parameters and penetration depth under different eccentricity are obtained respectively.In addition,the weakening effect of the top charge height on the initiation eccentric effect is revealed,and a better range of top charge height is obtained.(3)Based on the steady state theory,the liner is regarded as an ideal incompressible fluid,and the asymmetric effect of detonation wave on the liner collapse process is considered.The prediction model of jet transverse velocity is established.Compared with the numerical simulation results,it is shown that the prediction model can accurately describe the distribution of jet transverse velocity under different initiation eccentricities.(4)The numerical simulation research is carried out on the shape and position deviation of liner during the manufacturing process of shaped charge.A three-dimensional model of non-axisymmetric shaped charge is established by using finite element software,and the process of jet forming and penetration is simulated.The influence rule of the shape and position deviation of the shaped charge cover on the jet performance is explored,the influence mechanism of the shape and position deviation of the shaped charge cover on the collapse process and the jet power performance is revealed,and the allowable range of deviation to meet the jet power performance is established.The change law of jet shape and transverse velocity under the coupling of liner offset and deflection is discussed.The research results can provide a reference for the improvement of shaped charge manufacturing technology.(5)Through conducting pulse X-ray photography test and DOP test.The rationality and correctness of using numerical simulation method to study the jet forming process of shaped charge under the coupling of multiple macroscopic deviations are verified.Through a series of orthogonal tests,the main manufacturing deviation factors affecting the axial velocity,the transverse velocity and the length of the jet head and their influence laws are explored respectively.Based on the numerical simulation results of asymmetric jet penetration into the target plate,the main manufacturing deviation factors affecting the jet forming and penetration performance of shaped charge are revealed.