Journal
NDT & E INTERNATIONAL
Volume 45, Issue 1, Pages 104-110Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.ndteint.2011.09.002
Keywords
Lock-in thermography; PDE; ANN; Differential normalised phase; Quantification
Funding
- Chinese National Natural Science Foundation [60776802, 51074208, 51173034]
- Fundamental Research Funds for the Central Universities [HIT.NSRIF.2009025]
- 111 Project [B07018]
- Heilongjiang Provence Project [GB06A512]
Ask authors/readers for more resources
This paper describes the quantitative analysis of the boundary, location and depth of subsurface defects by lock-in thermography. The phase difference between defective areas and non-defective areas illustrates the qualitative analysis of the boundary and the location of the subsurface defect. In order to accurately estimate the size, location and depth of the defects, the phase is normalised, the heat transfer partial differential equation (PDE) model is used to filter the noise of normalised phase image and the differential normalised phase profile is employed to determine the boundary and location of the defect. The profile of the differential normalised phase distribution has maximum, minimum and zero points that help to quantitatively determine the boundary and location of the subsurface defect. An artificial neural network (ANN) is proposed to determine the depth of the subsurface defect. Experimental results for a steel plate, a carbon fibre-reinforced polymer (CFRP) sheet-foam sandwich, and honeycomb structure composites with artificial subsurface defects show good agreement with the actual values. (C) 2011 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available