H.M. Wen

EFFECTS OF ABRASION ON THE PENETRATION OF OGIVAL-NOSED PROJECTILES INTO CONCRETE TARGETS

This paper investigates the effects of abrasion on the penetration of an ogival-nosed projectile into concrete targets. A numerical procedure is constructed based on an abrasion model which is proposed based upon the experimental observations and a forcing function. The forcing function is a polynomial of the normal velocity which approximates the response of target and can be determined either empirically or theoretically or numerically. The proposed numerical procedure is easy to implement and can be used to calculate the time-histories of projectile velocity, penetration depth, deceleration, mass loss and its nose shape. It is found that the model predictions are in good agreement with available test data in terms of mass loss, penetration depth and nose shape change of the projectile.

Ballistic Penetration and Perforation of Thick FRP Laminates by Ogival-Nosed Projectiles

This article examines penetration and perforation of thick fiber-reinforced plastic (FRP) laminates struck by ogival-nosed projectiles at normal incidence. A forcing function representing the interaction between the projectile and the FRP laminates is derived by assuming that the deformation of FRP laminates is localized and that the pressure offered by the laminate targets to resist the projectiles is velocity dependent which can be divided into two parts: a quasi-static part due to the elastic-plastic deformation of the laminate materials and a dynamic part due to penetration velocity. Equations for axial force on the ogival nose are first obtained and then used to solve numerically the depth of penetration (DOP), residual velocity, ballistic limit, and time-histories of displacement/penetration, velocity and deceleration. Parametric studies are also carried out on the ballistic performance of projectiles with different caliber-radius-head (CRH). It transpires that theoretical predictions are in good agreement with available experimental results.

A Spherical Cavity Expansion Penetration Model for Concrete Based on Hoek–Brown Strength Criterion

Abstract A spherical cavity expansion model for concrete is first proposed by using an elastic-brittle-plastic material law with Hoek–Brown strength criterion. The constitutive model can capture the basic features of the mechanical response of concrete materials including the effects of strain-softening and pressure hardening (pressure-dependent shear strength) and all the parameters used in the model can be determined from material tests. The forcing function obtained from the spherical cavity expansion analysis is then employed to construct a penetration model for concrete targets struck by ogival-nosed projectiles. It transpires that the present model predictions are in good agreement with experimental observations in terms of penetration depth and ballistic limits/residual velocities in the case of perforation.