Original paper(Vol.47 No.8 pp.830)
Fracture behavior of plate glasses by projectile impact
Miyamoto Akihiko; Murakami Yukitaka
Abstract:On crime scenes, plate glass is frequently shot by bullets. The fracture of plate glass by a pachinko ball (steel ball) impact also occurs. Experiments were carried out to obtain basic data for estimating the impact velocities of projectiles from the morphology of the fracture. Projectiles {11mm dia. steel balls and 0.8 inch (9mm dia.) lead bullets} were shot onto ordinary glass plates firmly held around a circular periphery.
It was assumed that projectile kinetic energy would all be converted into surface energy of fractured glass. The relationship between crack area A sub f and kinetic energy of projectiles was investigated. A strong experimental correlation was found between A sub f and the change in kinetic energy. A unique relationship was obtained between crack area and energy consumed during fracture regardless of the projectile material (steel and lead).
Key Words:projectile impact, fracture, plate glass, impact velocity, surface energy, crack area