NCMS Project #: 140804
Problem: Safety glass is ubiquitous and takes many forms, ranging from polycarbonate material to glass laminates, and even to aluminum oxynitride ceramic. Safety glass is used in many, many applications (including automotive glass) where some degree of protection from foreign object strike is needed. “Bullet proof” glass laminate safety glass protects bank tellers and store clerks from actions of violent criminals. Polycarbonate lenses in safety glasses protect worker’s eyes. Any application where transparency is required but potential for damage from some sort of projectile is possible is a candidate application for safety glass.
Rock strike damage, crack propagation, and delamination are known issues with laminated safety glass. Damage to safety glass requires replacement; therefore both of these problems have increased the logistical and life cycle costs to the Army. The same problems plague auto and truck owners.
Benefit: Increasing the life of safety glass, by increasing its resistance to rock strike and delamination will reduce the life cycle costs of the Army’s tactical vehicle fleet (rock-strike damage accounted for 32% of the replacement cost of safety glass).
The technology being developed under this initiative will have benefits for the entire commercial safety glass market beyond purely military. The most common failure mechanisms for glass laminate safety glass are delamination and degradation of the external sacrificial layer. The initiative will address more reliably performing glass laminates with easier field replacement of the sacrificial layer. The learning from the initiative will better equip commercial industry to produce high quality glass laminate safety glass at an affordable price. It will not rely on the proprietary solutions of any one safety glass vendor, making the results broadly applicable.
Solution/Approach: The project will include theoretical study, modeling and/or empirical testing determine the failure mode mechanisms from rock strike events and delamination failures. A wide range of materials will be included in these activities, to represent a large cross-section of in-use safety glass. Industry-standard tests will be used, when available. New tests will be developed when needed, which will be published with the test results.
Impact on Warfighter:
- Reducing logistics footprint
- Reducing time to repair
- Reducing cost
- Improving readiness
- U.S. Army (TARDEC Material, Environmental & Corrosion)
- U.S. Marine Corps (Albany) observer
- Frisco, TX Police Department observer
- PPG Industries
- Oakland University
Technology Focus Area(s):
- Cost savings
- Maintenance avoidance & reliability
- Improved readiness