A simple method for defect area detection using active thermography

2009 ◽  
Vol 17 (4) ◽  
Author(s):  
S. Dudzik

AbstractIn this paper a simple method for defect area detection in the subsurface layer of materials was presented. The method uses active infrared thermography. A statistical detectivity ratio was introduced for a quantitative characterization of areas containing defects. The described algorithm of defect area detection was tested for a material with a low thermal diffusivity. The results of experimental and simulation investigations are presented. It was stated that the statistical detectivity ratio can be used to detect regions of defect presence, even for the non-uniformly heated surfaces.

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1604
Author(s):  
Shashank Pant ◽  
Parham Nooralishahi ◽  
Nicolas P. Avdelidis ◽  
Clemente Ibarra-Castanedo ◽  
Marc Genest ◽  
...  

Unmanned Aerial Vehicles (UAVs) that can fly around an aircraft carrying several sensors, e.g., thermal and optical cameras, to inspect the parts of interest without removing them can have significant impact in reducing inspection time and cost. One of the main challenges in the UAV based active InfraRed Thermography (IRT) inspection is the UAV’s unexpected motions. Since active thermography is mainly concerned with the analysis of thermal sequences, unexpected motions can disturb the thermal profiling and cause data misinterpretation especially for providing an automated process pipeline of such inspections. Additionally, in the scenarios where post-analysis is intended to be applied by an inspector, the UAV’s unexpected motions can increase the risk of human error, data misinterpretation, and incorrect characterization of possible defects. Therefore, post-processing is required to minimize/eliminate such undesired motions using digital video stabilization techniques. There are number of video stabilization algorithms that are readily available; however, selecting the best suited one is also challenging. Therefore, this paper evaluates video stabilization algorithms to minimize/mitigate undesired UAV motion and proposes a simple method to find the best suited stabilization algorithm as a fundamental first step towards a fully operational UAV-IRT inspection system.


2012 ◽  
Vol 55 (6) ◽  
pp. 469-474 ◽  
Author(s):  
César San Martin ◽  
Carlos Torres ◽  
Daniela Esparza ◽  
Daniela Bonilla

Author(s):  
Fulvio Mercuri ◽  
Roberta Gnoli ◽  
Stefano Paoloni ◽  
Noemi Orazi ◽  
Cristina Cicero ◽  
...  

AbstractWe present an opto-thermal approach based on the use of active infrared thermography (IRT) for the study of texts hidden inside the bookbinding structure of ancient books. In particular we focus our investigation on the detection and characterization of texts on paper scraps, belonging to earlier handwritten or printed leaves, used for the making of bookbindings and lying between the end papers and the cover. A qualitative description of the physical mechanisms allowing the identification of texts is proposed and a comparative analysis of the results obtained by means of different IRT experimental configurations is presented. The results show that active IRT can be a very useful tool for the detection and the identification of underlying texts whose reading can provide useful information on the specific history of ancient books.


2020 ◽  
Vol 8 (35) ◽  
pp. 12155-12163
Author(s):  
Xiumei Wang ◽  
Guocheng Zhang ◽  
Huihuang Yang ◽  
Yaqian Liu ◽  
Shaomin Chen ◽  
...  

A simple method was introduced to precisely characterize the interface stress of flexible OFETs using nanoindentation. The interface stress could be tuned by controlling the interface adhesion energy between layers, via controlling the film formation process.


2014 ◽  
Vol 59 (3) ◽  
pp. 893-897 ◽  
Author(s):  
K. Kochanowski ◽  
W. Oliferuk ◽  
Z. Płochocki ◽  
A. Adamowicz

Abstract The simple method of determining thermal diffusivity of solid materials at room temperature using the pulsed infrared thermography (IRT) is proposed. The theoretical basis of the method and experimental results are presented. The study was conducted on austenitic steel 316L. Theobtained results show that the thermal diffusivity value of the tested steel determined by means of pulsed infrared thermography is very approximate to the values given in the literature, obtained by using more complicated methods. The differences between these values are 0.5%.


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