IR Thermography Nondestructive Testing Methods of Composite Materials Used in Aerospace Applications

Abstract

In case of composite materials we have to deal with the presence of both high mechanical resistance parameters and low specific gravity. Hence in recent years their use rapidly grows in structures for which these characteristics are of paramount importance. There are mainly aerospace structures. Typical defects of composite materials are: delaminating, lack of adhesion, cracks, concentrations and deformations. These defects can come into being both in manufacturing processes and during exploitation. With the development of technology for producing composite materials the requirements are growing for assessment of their quality. For this purpose nondestructive testing (NDT) is used. NDT procedures using IR thermography can be divided into passive and active. For the diagnosis of defects in composite materials of aerospace applications the active IR thermography methods are used in many cases. The paper presents examples of selected results of defects detection and description of used methods.

Intelligent Thermal Imaging-Based Diagnostics of Turbojet Engines

“…IRT systems measure this energy to create thermal infrared images. These images can be used to identify heat radiation anomalies of an object, which are usually characterized by increases or decreases in the radiated temperature [8,9,13]. The basic principle of IRT diagnostics is shown in Figure 1, with the following general meaning:…”

“…The advantages of IRT have been fully demonstrated in pre-flight and post-flight aircraft checks, where damage (e.g., water in honeycomb structures of composite parts), is monitored by thermal imaging cameras [7,8]. In aviation, extensive research and development is being conducted on the IRT diagnostics of corrosion in aluminum materials [9,10], and especially composite structures [11][12][13]. In aircraft operation, it is possible to use IRT to detect air leaks inside the cabin [14], abnormal strain in individual parts of aircraft casings, fuselage, and wheel attachments [15], damage to electrical wiring and insulation [16,17], etc.…”