Author(s)

K. Miwa, M. Beppu, T. Ohno & M. Katayama

Abstract

This study is to investigate the mechanism of local damage in a concrete plate by the impact of hard projectile with a hemisphere-nose. Thus, to execute the experimental study, testing apparatus for launching the projectile was newly developed. Using this apparatus, a projectile with the mass of 100g is shot by at a velocity of about 500m/s. In this test, the relation between the impact velocity and the penetration depth and crater diameter were examined. The impacting appearance was recorded by a high-speed video camera, and then analyzed. Also, to find the mechanism of local damage in concrete, a numerical simulation by AUTODYN was performed. Keywords: hard projectile, impact, concrete plate, local damage, AUTODYN. 1 Introduction Recently everywhere in the world, explosive incidents due to terrorist’s attack and accident have been increased. In case of such incidents, structures and people may be secondary damaged due to bombing fragmentation. To establish a reliable protective design method of structures against fragmentation, the mechanism of local damage subjected to high-speed impact of projectile should be investigated. However, only a few tests were carried out in Japan because the special apparatus or facilities to execute the impact tests were required. On the other hand, numerical simulations using FEM or FDM have been progressed rapidly with the development of computer technology. For example, Ito et al. [1] performed the 3-dimensional numerical simulation of local damage in concrete wall subjected to the collision of heavy aircraft [1]. It is well known that, in the numerical simulation, analytical results for concrete structures are strongly affected by the material constants and/ or the constitutive model of concrete material.

Keywords

hard projectile, impact, concrete plate, local damage, AUTODYN.