Impact damage in layered glass

Abstract

High-velocity impact onto a layered glass target produces a very extensive damage pattern exhibiting many distinct morphologies. Material around the penetration cavity is finely comminuted. Under the arrested projectile, the glass is largely intact with spokelike fracture regions. Around the projectile cavity, needle fragments are formed; they are radial in outer layers and circumferential in inner layers. Extensive radial cracks occur in all layers, but the spacing and frequency of transverse fractures change in each layer. Damage from radial cracks also progresses from being hoop-stress-induced to flexural-induced through the depth of the target. Fan and dicing cracks occur near the periphery of the target. Mesoscale damage features include conventional mist and hackle markings indicating very fast cracks. The map of damage presented herein should be a valuable reference for attempts to model impact damage of glass.

Damage Development in Confined Borosilicate and Soda‐Lime Glasses

“…(a). These have also been reported by Bless in soda‐lime glass targets following high speed projectile impact. This phenomenon was not explored; further investigation is necessary to determine the growth kinetics.…”

“…Some melting was observed on glass adhered to the projectile. Bless investigated multilayered glass targets following projectile impact and documented the damage regions in individual layers. Nie and Chen studied the effects of temperature and confinement pressure on the dynamic response of damaged borosilicate glass.…”

Characterization of the Transient Response of Polyurea

“…6 Á " 0 , β and κ determine the thermal influence, T is the temperature and T 0 is a reference temperature. m and a are rate-sensitivity parameters.…”

“…There have been numerous studies of the dynamic failure behavior of ceramics used as transparent armor (see, for example [3,4,5]). Glass, laminated with alternating layers of polymers of varying thickness and fracture properties, is also a very commonly used as transparent armor [6]. The fracture behavior of glass is rather well understood after nearly a century of investigations; however, the design of these multilayered structures, and characterization of their performance, requires experimental measurements of the properties of individual constituents of the multilayer system.…”

An Introduction to the Properties of Silica Glass in Ballistic Applications

“…Also, lamination of glass with transparent polymer layers allows vehicle windshields or windows in buildings to withstand low‐velocity impact without shattering . Thicker versions are used in armoured vehicles to make them proof against even high‐velocity rifle bullets .…”