The unique properties of Terahertz (THz) radiation include among others the ability to penetrate through electrical insulators such as ceramics, plastics, or plastic composites. Because of that, it is possible to non-destructively and contact free analyze the materials with internal cavities both in transmission and reflection configuration. The commercially available low-power sources provide results which quality is still beyond expectations. As a result, efforts are being made to resolve the studies' focused on optimizing the experimental setup. In the presented work the comparison between two experimental setups operated at the frequencies of 100 GHz and 300 GHz was described. The studies were performed in transmission mode on selected composite material. They were next compared to the results obtained using common pulsed thermography. Some practical application in non-destructive testing and possible improvements of described methods are discussed.
With regards to composites, the need for non-destructive evaluation (NDE) of their inner structure, or constructions they form continuously rises. Nowadays, a great deal of attention has been paid to methods based on the use of Terahertz radiation (THz). It is related to the exceptional properties of THz radiation which allows for contactless, safe, and fast inspection of non-conductive materials. In the frame of this work the results of the use of the Terahertz imaging method, operated at the frequency of 300 GHz, are presented. The selected aramid fiber-reinforced composites with intentionally introduced defects were monitored. A thorough structural materials inspection was carried out in transmission mode. The obtained images were preprocessed and enhanced. Overall, the phenomenon of noninvasive monitoring using Terahertz radiation and the tremendous advances in this field were presented.
With regards to composite materials, the need for noninvasive evaluation of their structures, components, or systems they form continues to rise. It relates to the fact that composites, due to their two-phased (at least) composition, are vulnerable to different damages arising during their manufacturing or their use. Thus, there is a need to non-destructively monitor such materials especially when they are used in safety applications such as e.g., bulletproof vests and their damage may pose a real threat. In the frame of this work, the use of the newly developed non-destructive testing (NDT) method based on the application of Terahertz (THz) radiation was presented. For this purpose, the series of samples without defects and with a defect in their interior was investigated. The samples were prepared as the soft insert of a bulletproof vest and one of them had intentionally introduced defect in the form of aramid fibers textile soaked in salty water. The results obtained using the THz imaging method were compared to the ones obtained using the conventional X-ray method. Overall, the potential of THz transmission measurements was demonstrated and a selected application using THz-based system was presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.