Li, T., Almond, D. P. and Rees, D. A. S., 2011. Crack imaging by scanning laser-line thermography and laser-spot thermography. Measurement Science & Technology, 22 (3), 035701.
The thermographic images of laser-heated spots or lines are perturbed by nearby cracks, providing NDE techniques for crack detection. Scanning with a laser line, rather than a laser spot, results in a substantial reduction in inspection time. 3D finite difference modelling results are presented that show the sensitivity of the laser-line thermography technique to cracks of varying lengths, depths and openings. A novel crack imaging technique is presented that is based on assembling the second spatial derivative thermal images of a scanned laser line. Experimental results show the new technique to image cracks with openings as small as a few micrometres. The scanning time of the laser-line thermography technique is shown to be over an order of magnitude smaller than that of the laser-spot thermography technique whilst producing crack images of similar quality.
|Item Type ||Articles|
|Creators||Li, T., Almond, D. P. and Rees, D. A. S.|
|Uncontrolled Keywords||cracks, nondestructive evaluation, laser, thermography|
|Departments||Faculty of Engineering & Design > Mechanical Engineering|
|Research Centres||Materials Research Centre|
Aerospace Engineering Research Centre
|Publisher Statement||Almond_MST_2011_22_035701.pdf: © 2011 IOP Publishing Ltd; Almond_MST_2011_22_035701.doc: © 2011 IOP Publishing Ltd|
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