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
Projectile perforation of concrete slabs will produce numerous concrete fragments on the rear face of the concrete slabs. These concrete fragments will cause serious secondary damage to the indoor personnel and equipm...Projectile perforation of concrete slabs will produce numerous concrete fragments on the rear face of the concrete slabs. These concrete fragments will cause serious secondary damage to the indoor personnel and equipment of protective structures.Accurately evaluating the damage area of concrete slabs is an important problem. Therefore, a theoretical model of a rigid projectile perforation of concrete slabs is constructed using the energy method in this paper. In this model, a new shear failure method is proposed to calculate the energy consumption of the shear formation by combining with the von-Mises failure criterion and failure strain. Based on the energy conservation and principle of minimum potential energy, explicit equations for the perforation performance are formulated. The theoretical predictions agree well with the experimental results. Furthermore,experiments on a high-speed projectile normal perforation of concrete are carried out to verify the accuracy of the corresponding theoretical prediction.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supported by the National Natural Science Foundation of China(Grant Nos.11390362&11521062)
文摘Projectile perforation of concrete slabs will produce numerous concrete fragments on the rear face of the concrete slabs. These concrete fragments will cause serious secondary damage to the indoor personnel and equipment of protective structures.Accurately evaluating the damage area of concrete slabs is an important problem. Therefore, a theoretical model of a rigid projectile perforation of concrete slabs is constructed using the energy method in this paper. In this model, a new shear failure method is proposed to calculate the energy consumption of the shear formation by combining with the von-Mises failure criterion and failure strain. Based on the energy conservation and principle of minimum potential energy, explicit equations for the perforation performance are formulated. The theoretical predictions agree well with the experimental results. Furthermore,experiments on a high-speed projectile normal perforation of concrete are carried out to verify the accuracy of the corresponding theoretical prediction.
