Processing infrared (IR) images in non-destructive testing of multilayer aramid composite by IR thermography methods

Swiderski, Waldemar; Military Institute of Armament Technology; Poland

Hlosta, P.; Military Institute of Armament Technology ; Poland
Pracht, M.; Military Institute of Armament Technology ; Poland
Swiderski, W.; Military Institute of Armament Technology ; Poland

ID: ECNDT-0616-2018
Download: PDF
Session: Thermography and Thermosonics Applications
Room: H1
Date: 2018-06-14
Time: 15:40 - 16:00

Typical defects in multilayer composite structures are delamination, lack of adhesion, density, crushing, and inclusions of other materials. These defects can be detected by non-destructive testing methods. One of the more effective methods in testing of composite materials reinforced with aramid fiber is infrared thermography.
Non-destructive testing via thermographic methods, as well as other test methods, has limitations on types, geometric dimensions, and depth of defect below the surface of tested materials. It is used to process images (thermograms) obtained during experimental testing. In the process of analyzing hundreds of images containing details, they are replaced by a limited set of distinct features, prone to use of methods and algorithms for recognition. In addition to standard methods used in digital image processing, special data processing techniques are used, the most important of which are: thermal tomography, Fourier transform, wavelet analysis, thermographic signal reconstruction, dynamic thermography standardization, principle component analysis, neural networks, and data synthesis.
Selected examples of special methods of thermogram processing are shown in the example of pulsed thermography with the source of thermal stimulation of the examined samples, by means of a flash lamp and ultrasonic thermography.
The examples presented in this paper show the role that thermogram processing can play by using special methods for detecting a defect in tested materials.