Delamination Detection in Polymeric Ablative Materials Using Pulse-Compression Thermography and Air-Coupled Ultrasound

Ablative materials are used extensively in the aerospace industry for protection against high thermal stresses and temperatures, an example being glass/silicone composites. The extreme conditions faced and the cost-risk related to the production/operating stage of such high-tech materials indicate t...

Full description

Bibliographic Details
Main Authors: Stefano Laureti, Muhammad Khalid Rizwan, Hamed Malekmohammadi, Pietro Burrascano, Maurizio Natali, Luigi Torre, Marco Rallini, Ivan Puri, David Hutchins, Marco Ricci
Format: Article
Language:English
Published: MDPI AG 2019-05-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/19/9/2198
Description
Summary:Ablative materials are used extensively in the aerospace industry for protection against high thermal stresses and temperatures, an example being glass/silicone composites. The extreme conditions faced and the cost-risk related to the production/operating stage of such high-tech materials indicate the importance of detecting any anomaly or defect arising from the manufacturing process. In this paper, two different non-destructive testing techniques, namely active thermography and ultrasonic testing, have been used to detect a delamination in a glass/silicone composite. It is shown that a frequency modulated chirp signal and pulse-compression can successfully be used in active thermography for detecting such a delamination. Moreover, the same type of input signal and post-processing can be used to generate an image using air-coupled ultrasound, and an interesting comparison between the two can be made to further characterise the defect.
ISSN:1424-8220