Study On The Strength Of Projectile And Target Based On Compressible Fluid Model In Long-rod Penetration

The long rod is a kinetic weapon and can be used as a warhead for missiles and artillery shells.The study of long rod penetration is a hot topic in the field of national defence research.In recent years,hypersonic weapons have been used on the battlefield with the development of science and technology.The terminal guidance velocity can reach Mach5～15,which has reached the ultra-high velocity range(≥3km/s).It is therefore important to study the hypervelocity penetration of long rod.Based on the compressible fluid model,the following work has been carried out in this paper on the strength problem of the projectiles and targets in long rod penetration:(1)Combined with previous theoretical models of long-rod penetration,this paper analyzed the role of the strength of the projectile and the target in the long-rod penetration process.The effects of the strength of projectile and target,as well as volumetric strain on penetration results were discussed in aspects of both penetration depth and interface pressure.Furth more,we presented the differences in the strength of the projectile and the target in different theoretical models as well as the advantages and disadvantages of the different models.The results show that the values of the strength of projectile and target in the existing theoretical model are not uniform,which directly affects the thorough results.(2)Based on numerical models and compressible fluid model,the decoupling analysis is performed on the strength of projectile and target.Decoupling analysis was performed on the strength of projectiles and targets based on numerical models and compressible fluid model.First,we obtained the changes of interface pressure under the conditions of different combinations of projectile and target through numerical simulation,and then analyzed the composition of the interface pressure through Fils’ s equation.On this basis,we discussed the projectile and the target separately,and used the interface pressure as the independent variable to analyze the contribution of each component to the interface pressure.(3)Based on the analytical method for projectile and target strength in the compressible fluid model,we considered the role of the internal energy in the interface and obtained the change of Yp and Rt with interface pressure and penetration velocity under different combinations of projectile and target.We then gave the strength mechanisms of projectiles and targets in terms of strain rate effect and compressibility of material,and the values of the strength for projectile and target are clarified for different penetration velocity intervals.(4)Combining the theoretical model and experimental data of other researchers,we verified the rationality of the strength of projectile and target;we then discussed the competing relationships between the strength of projectile and target and the compressibility in different invasion velocity intervals.The high speed penetration of long rod projectile is partitioned based on the strength of projectile and target and the material compressibility,and the key parameters of compressible fluid penetration theoretical model in different velocity intervals were given.