Optical Material Characterisation of Prepreg CFRP for Improved Composite Inspection

Automated fibre layup techniques are often applied for the production of complex structural components. In order to ensure a sufficient component quality, a subsequent visual inspection is necessary, especially in the aerospace industry. The use of automated optical inspection systems can reduce the inspection effort by up to 50 %. Laser line...

Extreme shearography: Development of a high-speed shearography instrument for quantitative surface strain measurements during an impact event

Monitoring of extreme dynamic loadings on composite materials with high temporal and spatial resolution provides an important insight into the understanding of the material behaviour. Quantitative measurement of the surface strain at the first moments of the impact event may reveal the initiation of the failure mechanisms leading to damage....

Effects of high-amplitude low-frequency structural vibrations and machinery sound waves on ultrasonic guided wave propagation for health monitoring of composite aircraft primary structures

A reliable damage diagnostic by ultrasonic guided wave (GW) based structural health monitoring (SHM) can only be achieved if the physical interactions between wave propagation, the SHM system and environmental factors are fully understood. The purpose of this research was to gain knowledge about the effects of high-amplitude low-frequency...

EXTREME shearography: High-speed shearography instrument for in-plane surface strain measurements during an impact event

This work presents the design and the latest experimental results on the surface strain measurements during an impact event obtained with the EXTREME high-speed shearography instrument. The shearography technique is used in this project to provide a quantitative measurement of the surface strain development at the first moments of the impact...

Image analysis for classification of damaged and undamaged areas on composite structures

Composite materials are susceptible to barely visible impact damages (BVID) due to low-velocity impact. Therefore, an automated damage detection and quantification technique is highly desirable for quick inspection of large number of composite structures. Among various different non-destructive techniques (NDTs), active thermography NDT can...

A Method for Studying Climate-related Changes in the Condition of Decorated Wooden Panels

Museum objects are often highly complex and composed of materials with varying properties, some of which may have changed as a result of ageing and/or conservation treatments. Research into defining sustainable environmental conditions by balancing energy cost and risk to these vulnerable objects has mainly focused on experiments in...

EXTREME shearography: Development of a high-speed shearography instrument for measurements of the surface strain components during an impact event

This work presents the design and preliminary results of a high-speed shearography instrument in development for surface strain components measurements during an impact event. Composite materials are vulnerable to extreme dynamic loadings such as blade off events or foreign object damage as their mechanical properties are strain rate...

3.12 Inspection and Monitoring of Composite Aircraft Structures

The new generation of civil aircraft, including the Airbus A380 and the Boeing 787, are composed of composite materials for their primary aircraft structures. This presents a challenge for airline maintenance, repair, and overhaul (MRO) operations in both the short- and long-term. In the short-term, new technologies are needed for maintenance,...

Signal processing in optical coherence tomography for aerospace material characterization

Based on a customized time-domain optical coherence tomography (OCT) system, a series of signal processing approaches have been designed and reviewed. To improve demodulation accuracy and image quality, demodulation approaches such as median filter, Hilbert transform, and envelope detector were investigated with simulated as well as experimental...