A rigid elliptical cross-sectional projectile with different geometrical characteristics penetration into concrete target

Abstract

Elliptical cross-sectional projectiles have recently attracted attention because they fit the flattened shape of earth-penetrating weapons. This study aims to investigate a rigid elliptical cross-sectional projectile with different geometrical characteristics penetration into the semi-infinite concrete targets by implementing a theoretical method. The general geometric models of four types of elliptical cross-sectional projectiles are introduced; closed-form penetration equations are then derived based on the dynamic cavity-expansion theory. Furthermore, the present models are validated by comparing the predicted penetration depths with the predictions obtained using the semi-empirical formulae and test data; the maximum deviation from the test data is 15.8%. In addition, the deceleration, velocity, and displacement of the projectiles during the penetration process are obtained based on the present models, and the penetration performance of the four types of elliptical cross-sectional projectiles is discussed by comparing the penetration depths. The conical-nose elliptical cross-sectional projectile exhibits the best penetration performance than the other three types if the nose length is sufficiently large, and the ogive-nose elliptical cross-sectional projectile gradually exhibits its penetration performance advantage with the increase in the nose length.

Analytical and experimental study on elliptical cross-section double-ogive-nose projectile penetration into plain concrete target

“…In this section, based on our previous work (Dai et al 2020;Dai et al 2021), a semi-analytical formula is proposed to calculate the terminal ballistic parameters of the ECDP penetration into semi-infinite plain concrete target.…”

“…Several formulas have been proposed to predict the axial resistance of the ECSPs penetration into the semi-infinite concrete targets (Dai et al 2020;Dai et al 2021). In the present study, parts 1, 2, and 3 can be considered as ogival nose, truncated ogival nose, and truncated conical nose of the ECSPs, respectively.…”

“…Further, the subscript "n" represents the different parts of the ECDP. From Dai et al (2020), A n and B n are obtained as shown in Eq. ( 2).…”

“…In Eq. ( 2), ρ and α are the polar coordinate transformation parameter (Dai et al 2020), ρ t and R represent the density and the resistance parameter of the concrete target, respectively. R = Sf c was first proposed by Frew et al (1998), where f c refers to the unconfined compressive strength of the concrete target, and S refers to the empirical constant of the concrete target, which is given by S = 72.0f c -0.5 and S = 82.6f c -0.544 (Frew et al 1998;Li and Chen 2003).…”

“…In recent years, the terminal ballistic effect of the elliptical cross-section single-ogive-nose projectile (ECSP) penetration into the plain concrete target has been studied. Dai et al (2020Dai et al ( , 2021 proposed the closed-form penetration formula of the ECSP based on the cavity-expansion theory, and discussed the penetration performance of the ECSP. Moreover, the penetration-depth increment of the ECSP was evaluated, and the influence of the major-minor axis ratio on the penetration-depth increment was discussed.…”