A review provided about non-destructive testing (NDT) methods for the evaluation of composites. The review considers the capabilities of most common methods in composite NDT applications such as Visual Testing (VT or VI), Ultrasonic Testing (UT), Thermography, Radiographic Testing (RT), Electromagnetic Testing (ET), Acoustic Emission (AE), and Shearography Testing with respect to advantages and disadvantages of these methods. Then, methods categorized based on their intrinsic characteristics and their applications.

https://cyberleninka.org/article/n/593997.pdf

A review of non-destructive testing methods of composite materials

Bonded repair of composite aircraft structures: A review of scientific challenges and opportunities

https://hal.archives-ouvertes.fr/hal-01005683/document

The detection of aeronautical defects in situ on composite structures using Non Destructive Testing

Damage identification in aircraft composite structures: A case study using various non-destructive testing techniques

Shearography is a full-field speckle interferometric technique used to determine surface displacement derivatives. For an interferometric technique, shearography is particularly resilient to environmental disturbances and has hence become an invaluable measurement tool outside of the optics laboratory. Furthermore, the inclusion of additional measurement channels has turned shearography from a qualitative inspection tool into a system suitable for quantitative surface strain measurement. In this review article we present a comprehensive overview of the technique, describing the principle of operation, optical configurations, image processing algorithms and applications, with a focus on more recent technological advances.

/pdf/shearography-technology-and-applications-a-review-383g7ymz1d.pdf

Shearography technology and applications: a review

The new all-composite wing for semi-aerobatic sport and training aircraft is being developed in the Czech aircraft industry. The typical outer composite structure of this wing is sandwich with carbon skins in combination with honeycomb. This new composite structure is designed in accordance with CS-23 airworthiness requirements. The NDI techniques for reliable detecting of manufacture or in-service defects (disbonding, defects from impact, etc.) are therefore, necessary. This paper compares the results of visual, ultrasonic C-Scan and laser shearography impact damage assessment and determination of sandwich panels, which were cut out from sandwich skins of this developmental wing. Considering the reliability, simplicity and rapidity of each technique and with the digital indicator measurement as a base, the laser shearography is evaluated as the most suitable method for that purpose.

Radek Lohonka

Papers

Ultrasonic C-Scan and shearography NDI techniques evaluation of impact defects identification