A Research On The Applicability Of The Cavity Expansion Model In Low Velocity Penetration

The formula of cavity expansion model is a formula of penetration depth for the majority of researchers to know and recognize the penetration depth.For a long time,the scholars have made great progress in the research of penetration problem based on the theory of cavity expansion model.But in recent years,the applicability of the cavity expansion model in low velocity penetration has been questioned by scholars.It is found that the results obtained by using the cavity expansion theory model can not fit the experimental data very accurately.Some scholars doubt the applicability of cavity expansion model under low velocity penetration.The above dispute has not yet been resolved.In this study,the applicability of the theory of cavity expansion model to low velocity penetration is studied by the experiment.Through the reasonable selection of target materials and design experiments,a large range of penetration experiment results are obtained.Study found that: 1,in the low penetration,in the cavity expansion prediction model of penetration depth formula results in the presence of certain inaccuracy;2,Rosenberg about in the process of penetration projectile are the theory of penetration resistance constant is unreasonable.For strain rate sensitive target material,the resistance is not constant in the process of penetration.Only when the strain rate is not sensitive to the target material,the resistance of the projectile in the penetration process is nearly constant.By removing the inertia effect of the original cavity expansion model and introducing the material strain rate effect,the calculation formula of penetration resistance is modified.We also calculated the nose factor of the new model.The results show that the new calculation model and the test results are in good agreement.