Traditional pulsed thermography is unsuitable for detecting surface breaking cracks predominantly perpendicular to the sample surface. Pulsed laser spot thermal imaging is an effective alternative method. This paper presents modelling results of a full 3-D model of the technique that elucidate the roles of defect geometry and system set up in determining defect detection sensitivity. A new image processing method is also presented that has been applied to extract images of surface cracks in metal test-pieces. Both 3-D modelling and experimental results show that scanning pulsed laser spot thermography has considerable potential as a remote, non-contact imaging technique for surface cracks with openings of only a few micrometers.
|Name||AIP Conference Proceedings|
|Publisher||American Institute of Physics|
|Conference||36th Annual Review of Quantitative Nondestructive Evaluation|
|Country||USA United States|
|City||University of Rhode Island, Kingston|
|Period||26/07/09 → 31/07/09|