Pulsed Thermography Method for Delamination Detection of Glass Fiber Composites

Pulsed thermography (PT) has been used in the past several years for the nondestructive testing of different types of materials in particularly composite materials. The pulsed thermography technique has proven to be appropriate for the recognition and detection of most types of defects generally found in composite materials such as delaminations, impact damage and disbonds. However, post processing of images is a necessary step of the examination process. An extensive range of methods have been developed from the traditional thermal-based methods to signal transformation algorithms on which temporary information is transformed to a different domain (frequency, Hough etc.) with the objective of simplifying raw data. In this paper, three of these post processing methods are compared by applying them to a fiber glass sample. The results show advantages of the phase pulsed thermography method in delamination detection of fiber glass sample.