Pitfalls in High Stakes Environmental Chamber Testing for Transparent Armor

Transparent armor, also known as ballistic glass, is a primary sustainment cost for tactical wheeled vehicle programs, accounting for 10’s of millions of dollars annually. The “Accelerated Life Test” is required in first article testing, and is an effective predictor of part life. However, the test takes 4-6 months and is expensive. Passing the test is a major hurdle, contributing to backlogs for critical Marine Corps and Army tactical vehicles. The test is also a very ‘high stakes’ test because it is only required once per design and is a primary factor in determining selection of the winning company bid. While the test requirements appear simple, multiple seemingly minor test errors have had dramatic effects on the test results. It is critical for both manufacturers and government program offices to understand how to properly run the test, analyze results, and report the results in a way that can be confidently accepted as a technically sound measure of part quality. This work highlights key pitfalls using a thermal model to show their potential effect. Recommendations are provided for correctly running and reporting the test.