Applications of pulse heating thermography and lock-in thermography to quantitative nondestructive evaluations

Damage investigation in CFRP composites using full-field measurement techniques: Combination of digital image stereo-correlation, infrared thermography and X-ray tomography

“…whose effects are recovered in reflection or in transmission; a so-called active approach is particularly suitable for NonDestructive Testing (NDT) to reveal internal defects [28][29][30]; and/or deformation of the material itself due to thermoelastic coupling and heat dissipations when the material is affected by irreversible mechanisms [13]; such passive approach is of particular interest for monitoring damage under stress with many applications in fatigue [31,32]; this kind of procedure has been employed in the present study.…”

Development of Infrared Techniques for Practical Defect Identification in Bonded Joints

“…The speckle pattern is compared for a loaded and unloaded state using a shearing device, such as a Michelson interferometer, to identify any change in the speckle pattern that is caused by deformation of the material surface [70]. Mechanical loading is typically used; PhD Thesis 30 however, thermal loading may also be used in less accessible locations. The main advantage of thermal loading is its non-contact nature, however it is also more difficult to apply a uniform thermal load across an area.…”

“…One of the most common techniques used to simulate defects in metallic materials and ceramics is to mill a flat bottom hole in the rear of the sample thus creating a locally thinned material to simulate a defect [30]. This method originated as a method of simulating corrosion in metals but has been used for other purposes and applied to the study of composites.…”

“…To date, PPT has been successfully tested on its ability to detect defects in a range of different materials including aluminium (maximum resolved defect depth of 5 mm) [30], acrylic (8 mm), copper (2 mm) and ceramic (5 mm) [30], steel (4.5 mm) [113] and CFRP (2.5 mm) [77].…”

Nondestructive inspection of luxury yacht glass reinforced composite panels by means of transient thermography

“…Pulsed thermography (PT), in which the specimen is heated for few seconds and the thermal decay response at the surface is measured by the infrared camera, is one of the most common thermal stimulation method [3][4][5][6]. Subsurface defects will partially reflect or stop heat flows, producing hot spots (in a reflection set-up) or cold spots (in a transmission set-up) on the analysed specimen surface.…”