Oblique perforation of thick metallic plates by rigid projectiles with various nose shapes is studied in this paper. Two perforation mechanisms, i.e., the hole enlargement for a sharp projectile nose and the plugging ...Oblique perforation of thick metallic plates by rigid projectiles with various nose shapes is studied in this paper. Two perforation mechanisms, i.e., the hole enlargement for a sharp projectile nose and the plugging formation for a blunt projectile nose, are considered in the proposed analytical model. It is shown that the perforation of a thick plate is dominated by several non-dimensional numbers, i.e., the impact function, the geometry function of projectile, the non-dimensional thickness of target and the impact obliquity. Explicit formulae are obtained to predict the ballistic limit, residual velocity and directional change for the oblique perforation of thick metallic plates. The proposed model is able to predict the critical condition for the occurrence of ricochet. The proposed model is validated by comparing the predictions with other existing models and independent experimental data.展开更多
A perforation model is developed to predict the attitude deflection in the oblique perforation of concrete targets by a rigid projectile,in which the inertial moment of the projectile is introduced,together with takin...A perforation model is developed to predict the attitude deflection in the oblique perforation of concrete targets by a rigid projectile,in which the inertial moment of the projectile is introduced,together with taking the attitude deflection during the shear plugging sub-stage into account,and the shape of the plug formed on the rear surface of target is also re-investigated.Moreover,a new classification of concrete targets is proposed based on the target thickness,with which the attitude deflections in different kinds of concrete targets are analyzed.It is found that the numerical results by using the new perforation model are in good agreement with the previous experimental data and simulated results.Furthermore,the variations of the attitude deflection with the initial conditions(the initial attitude angle and the initial impact velocity) are investigated.展开更多
A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of t...A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of the penetration process.A numerical tool using AUTODYN hydrocode is applied in the study.The numerical results on both deceleration-time history and depth of penetration of projectiles are in good agreement with experimental data,which demonstrate the feasibility of the numerical model in these conditions.Based on the numerical model with a two-staged pre-drilled hole,the rigid projectile penetration in tunneling stage is studied for concrete targets with different strengths in a wide range of impact velocities.The results show that the penetration in tunnel stage can be divided into two different cases in terms of initial impact velocity.In the first case,when the impact velocity is approximately less than 600 m/s,the deceleration depends on initial impact velocity.In the second case,when the impact velocity is greater than 600 m/s,the effect of target inertia becomes apparent,which agrees with commonly used concrete penetration resistance equations based on cavity expansion model.展开更多
文摘Oblique perforation of thick metallic plates by rigid projectiles with various nose shapes is studied in this paper. Two perforation mechanisms, i.e., the hole enlargement for a sharp projectile nose and the plugging formation for a blunt projectile nose, are considered in the proposed analytical model. It is shown that the perforation of a thick plate is dominated by several non-dimensional numbers, i.e., the impact function, the geometry function of projectile, the non-dimensional thickness of target and the impact obliquity. Explicit formulae are obtained to predict the ballistic limit, residual velocity and directional change for the oblique perforation of thick metallic plates. The proposed model is able to predict the critical condition for the occurrence of ricochet. The proposed model is validated by comparing the predictions with other existing models and independent experimental data.
基金This work was supported by the National Natural Science Foundation of China[grant numbers 11521062].
文摘A perforation model is developed to predict the attitude deflection in the oblique perforation of concrete targets by a rigid projectile,in which the inertial moment of the projectile is introduced,together with taking the attitude deflection during the shear plugging sub-stage into account,and the shape of the plug formed on the rear surface of target is also re-investigated.Moreover,a new classification of concrete targets is proposed based on the target thickness,with which the attitude deflections in different kinds of concrete targets are analyzed.It is found that the numerical results by using the new perforation model are in good agreement with the previous experimental data and simulated results.Furthermore,the variations of the attitude deflection with the initial conditions(the initial attitude angle and the initial impact velocity) are investigated.
基金This work was supported by the National Natural Science Foundation of China(Grant 11390362)the Young Foundation of Shanxi University of Finance and Economics(Grant Z06134).
文摘A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of the penetration process.A numerical tool using AUTODYN hydrocode is applied in the study.The numerical results on both deceleration-time history and depth of penetration of projectiles are in good agreement with experimental data,which demonstrate the feasibility of the numerical model in these conditions.Based on the numerical model with a two-staged pre-drilled hole,the rigid projectile penetration in tunneling stage is studied for concrete targets with different strengths in a wide range of impact velocities.The results show that the penetration in tunnel stage can be divided into two different cases in terms of initial impact velocity.In the first case,when the impact velocity is approximately less than 600 m/s,the deceleration depends on initial impact velocity.In the second case,when the impact velocity is greater than 600 m/s,the effect of target inertia becomes apparent,which agrees with commonly used concrete penetration resistance equations based on cavity expansion model.
