Effects of Surface Treatment and Interfacial Strength on the Damage Propagation in Layered Transparent Armor under Impact

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. This research program is to develop a fundamental understanding of the damage propagation through layered transparent armors under impact loading conditions. The effects of surface quality and interfacial bonding strength on the damage propagation or arrest will also be examined. During the funded period of the program, a gas gun has been developed and used to impact layered glass targets. Notched glass specimens having adhesive interfaces are impacted with plastic projectiles. It is found that, an impact-induced crack arrests at an interface ABSTRACTThis research program is to develop a fundamental understanding of the damage propagation through layered transparent armors under impact loading conditions. The effects of surface quality and interfacial bonding strength on the damage propagation or arrest will also be examined. During the funded period of the program, a gas gun has been developed and used to impact layered glass targets. Notched glass specimens having adhesive interfaces are impacted with plastic projectiles. It is found that, an impact-induced crack arrests at an interface perpendocular to the crack path if the interface is not bonded. When the interface is bonded tightly, the crack passes through the interface in its propagation without being affected by the interface. When the bonded interface has a finite thickness, the crack slows down at the interface and then branches to many cracks that form a fan shape. Besides the crack experiments, the effects of surface quality on bending strength of glass are also investigated.(a) Papers published in peer-reviewed journals (N/A for none) The number of undergraduates funded by this agreement who graduated during this period with a degree in science, mathematics, engineering, or technology fields: (d) Manuscripts Number of Peer-Reviewed Conference Proceeding publications (other than abstracts): 2 NumberThe number of undergraduates funded by your agreement who graduated during this period and will continue to pursue a graduate or Ph.D. degree in science, mathematics, engineering, or technology fields:Number of graduating undergraduates who achieved a 3.5 GPA to 4.0 (4.0 max scale): Number of graduating undergraduates funded by a DoD funded Center of Excellence grant for Education, Research and Engineering:The number of undergraduates funded by your agreement who graduated during this period and intend to work for the Department of DefenseThe number of undergraduates funded by your agreement who graduated during this period and will receive scholarships or fellowships for further studies in science, mathematics, engineering or technology fields: Student Metrics This section only applies to graduating undergraduates supported by this agreement in this reporting perio...