Enhanced Infrared Image Processing for Impacted Carbon/Glass Fiber-Reinforced Composite Evaluation.

Hai Zhang,Xavier Maldague,Theodore Matikas,Stefano Sfarra,Ahmad Osman,Nicolas Avdelidis,Henrique Fernandes,Clemente Ibarra-Castanedo

doi:10.3390/s18010045

Abstract

In this paper, an infrared pre-processing modality is presented. Different from a signal smoothing modality which only uses a polynomial fitting as the pre-processing method, the presented modality instead takes into account the low-order derivatives to pre-process the raw thermal data prior to applying the advanced post-processing techniques such as principal component thermography and pulsed phase thermography. Different cases were studied involving several defects in CFRPs and GFRPs for pulsed thermography and vibrothermography. Ultrasonic testing and signal-to-noise ratio analysis are used for the validation of the thermographic results. Finally, a verification that the presented modality can enhance the thermal image performance effectively is provided.

Highlights

Composite materials are being increasingly used in aircraft, vehicles, ships, and sports equipment thanks to their significant weight reduction at the same strength
A pre-processing modality was presented for IRT and various cases were studied involving different defects in CFRP and GFRP specimens
After pre-processing, less useful empirical orthogonal functions (EOF) are needed from principal component thermography (PCT) because the pre-processing reduces the surface and surrounding noise, e.g., surface feature B

Summary

Introduction

Composite materials are being increasingly used in aircraft, vehicles, ships, and sports equipment thanks to their significant weight reduction at the same strength. The defects that are produced accidently at the manufacturing phase will affect the safety of the products. It is important to develop the inspection techniques to assess the products. Non-destructive testing (NDT) is a more practical solution than the above-mentioned destructive technique. Traditional NDT techniques include ultrasonic testing, magnetic flux leakage and X-ray computed tomography, etc. These techniques are well studied and nowadays established for quality control; each of them has some specific limitations for different types of defects

Methods

Results

Conclusion