Towards safe shearography inspection of thick composites with controlled surface temperature heating

Thick glass fiber-reinforced polymer (GFRP) composites, e.g. thickness of more than 50 mm, are increasingly used in a wide variety of industries, particularly in the marine and wind energy sectors. Defect detection and characterisation in these composites remain appealing challenges due to the material complexity and the presence of various...

Comparative performance of high and medium resolution cameras for defect detection in carbon-fiber reinforced composites by digital shearography

The performance of defect detection in composite materials using digital shearography is important for correct decision-making in non-destructive testing. In this work, we compared a high-resolution 24-megapixel digital still camera (DSLR) and a conventional medium-resolution 5-megapixel camera to determine the detectability of blind holes in...

Shearography non-destructive testing of a composite ship hull section subjected to multiple impacts

The use of thick composites and sandwich structures is increasing rapidly in marine, aerospace, and wind energy industries [1–3]. For example in the marine sector, sandwich structures consisting of glassfiber laminate skins bonded to a foam core are attractive because of the advantages of being light-weight, resistant to corrosion and underwater...

Shearography non-destructive testing of thick GFRP laminates: Numerical and experimental study on defect detection with thermal loading

Thick composite materials are commonly used as load-bearing structures in marine applications. Developing a suitable and sophisticated non-destructive testing (NDT) method for thick composites is an urgent challenge to improve the safety, reliability and maintenance of these structures. Digital shearography has become an important NDT...

FEM-assisted shearography with spatially modulated heating for non-destructive testing of thick composites with deep defects

This study aims at improving shearography non-destructive testing (NDT) of deep defects in thick composites with thermal loading. Instead of conventional global heating (GH), the core idea is to apply novel spatially modulated heating (SMH) for shearography NDT. In this paper, the finite element method (FEM) has been used to advance...

Spatially modulated thermal excitations for shearography non-destructive inspection of thick composites

With the increasing application of thick composites in marine, wind energy and aerospace industries, the inspection of thick composites becomes more and more challenging when considering the variety of thick structures (e.g., laminate, sandwich, honeycomb structures). Shearography is a full-field and non-contact optical non-destructive...

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....

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...

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...