NONDESTRUCTIVE CHARACTERIZATION OF LOW VELOCITY IMPACT DAMAGE IN TRANSPARENT LAMINATE SYSTEMS

摘要

Advanced transparent materials are used in applications such as face shields, riot gear, and windows to improve protection efficiency for soldiers and lightweight vehicles. These materials must be able to withstand single and multiple impacts from various threats while maintaining sufficient visibility for the vehicle operator. While damage that compromises structural integrity and impedes visibility is likely to result from high velocity impact events during combat, it may also be the result of low velocity impacts from collisions, severe environmental conditions, or foreign object debris. In this study, multi-layer, multi-material transparent laminate systems will be evaluated by comparing baseline conditions to experimentally controlled damage states. Factors such as strike face glass type and second layer glass type will be explored to evaluate both thin, novel transparent materials and standard transparent materials used in laminate systems. Destructive testing including air gun, sphere impact, and drop tower testing will be used to simulate a wide range of low velocity impacts. Characterization of the damaged state will include visual inspection, cross-polarization, and ultrasound techniques. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for transparent materials used in protective systems.