Flying Laser Spot Thermal Wave IR Imaging

Wang, Y. Q.; Chen, P.; Kuo, P. K.; Favro, L. D.; Thomas, R. L.

doi:10.1007/978-1-4615-3344-3_57

Cited by 4 publications

(2 citation statements)

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“…Since the horn is not rigidly adhered to the test-piece it is observed to chatter chaotically, typically generating broadband harmonic content in a non-repeatable manner [1]. Though there are variations on how laser-spot thermography is performed [5][6][7][8][9][10], the basis is always use of a laser to spot-heat the surface of the test-piece, and measurement of the surface temperature a distance away from the laser-spot. Given the non-repeatability and chaotic frequency content of a thermosonic inspection, the 'heating index' was developed by Morbidini and Cawley [3,4] to provide a measure of the ability of the applied vibration field to generate heat at any defects that may be present.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Crack Opening on Thermosonics and Laser-Spot Thermography

Weekes¹,

Cawley²,

Almond³

et al. 2010

AIP Conference Proceedings

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Laser-spot thermography is a novel method for detecting surface breaking cracks in metals. Another active thermographic research method is thermosonic (Sonic IR) inspection, which may potentially compete with or complement laser-spot thermography in the detection of surface breaking cracks. Thermosonic inspection generates heat predominantly by friction of crack-faces under high-power ultrasonic excitation, the resulting surface temperature rise being imaged with an infrared camera. Thermosonic inspection is therefore best suited to defects that are closed over part of their length. In contrast, laser-spot thermography detects defects by the perturbation of the radial heat flow from a spot heated with a short-pulse laser, the increased thermal impedance presented by air between the faces of the crack blocking the conduction of heat. This paper presents an experimental comparison of the performance of thermosonics and laser-spot thermography on a series of samples with different crack sizes, the opening of each crack being varied by three-point bend loading.

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Section: Introductionmentioning

confidence: 99%

The Effect of Crack Opening on Thermosonics and Laser-Spot Thermography

Weekes¹,

Cawley²,

Almond³

et al. 2010

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…Although most researchers have used this concept in the traditional way (in relation to pulse excitation techniques). A special case of active thermography is the so called flying-spot method [1,2], which is also known as the beam displacement modulation method [3,4]. In this case, the excitation of variable heat flux in an object is a result of a moving energy source upon the object's surface.…”

Section: Introductionmentioning

confidence: 99%