The Principle Of Crater-formation Of A Concrete Target Plate Penetrated By A Projectile
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G. Shiqiao, J. Lei, L. Haipeng & L. Kejie
Based on a series of experimental and theoretical analyses for a concrete target penetrated by a projectile, a 4-stage model of crater-forming is presented in which the forming process of a crater is divided into 4 stages. Based on the Normal Expansion Theory, the analytical expressions of resistant forces on the projectile are given. Through analysing tensile fracture and considering dynamical cracks bifurcation and propagation, the sizes of craters are calculated. They are in good agreement with the test results. Keywords: crater, concrete target, penetration, projectile. 1 Introduction Many efforts have been made in the past 100 years to predict the dynamic characteristic of a projectile impacting, penetrating, perforating and damaging a concrete target [1–4], but a few are about the formation of a crater on the front surface of the target. When a concrete target plate with brittle material behavior is penetrated by a projectile, an unavoidable crater on its front surface will occur. The sizes of the crater depend usually on the striking velocity, the shape and sizes of projectile nose, and the mechanical behavior of the concrete material. The forming process of a crater is the initial sub-process among the entire penetration process. It is very difficult to analyze in mechanics. On one hand, the forming process of a crater is an important sub-process of the total penetration process. On the other hand, the formation of crater is too complex to accurately evaluate by general analytical or numerical methods. Up to now, the principle of crater-forming has not been well explained. The expressed formula of resistant forces of target on the projectile in this sub-process has not been analytically
crater, concrete target, penetration, projectile.