Non-destructive inspection of military-designated composite materials with the use of Terahertz imaging

With regards to non-destructive (NDT) testing of the structural materials, the need for developing new experimental methods allowing for safe, contactless, and fast inspection, continues to rise. The phenomenon of the Terahertz imaging NDT method has been described within the presented study. In doing so, the fiber-reinforced aramid composites, that is, commonly used ballistic cover material, with intentionally introduced defects in a form of plates located at various depths below the samples’ surface, were meticulously investigated. The aim was to clearly detect the disturbances in the materials’ interior using newly developed Terahertz imaging in transmission mode. It has been concluded that the Terahertz-based method is a very effective tool in defect detection, and it allowed for the detection of each implemented flaw with high resolution. Overall, the advantages and limitations of this method in the non-invasive inspection of composites are discussed and the potential application is demonstrated.