A defect shape reconstruction algorithm for pulsed thermography

Lugin, S.; Netzelmann, U.

doi:10.1016/j.ndteint.2006.11.001

Cited by 46 publications

(20 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To obtain a rough idea of the back wall geometry, we applied the echo defect shape method, for details see Lugin [6]. To derive this depth formula, the analytical 1D solution for the heat equation is calculated for a specimen with semi-infinite thickness which is exposed to a Dirac delta pulse heating on the front.…”

Section: Initial Geometry Using the Echo Defect Shape Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Numerical method of active thermography for the reconstruction of back wall geometry

Richter¹,

Maierhofer²,

Kreutzbruck³

2012

Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography

View full text Add to dashboard Cite

The paper presents a numerical method to detect and characterise defects and inhomogeneities by means of active thermography. The objective is to determine the wall thickness of structure elements with an inaccessible back wall, e.g. of pipes or containers. As test specimens we used 2 cm thick PVC samples with flat bottom holes in the back wall. Flash lamps provided the heating. The inversion method is the Levenberg-Marquardt method, which starts by a rough first guess of the back wall geometry using the echo defect shape method, and then the PVC thickness of specimen profiles was calculated. We validated the result by comparing the measurement data to simulated data for selected geometries.

show abstract

Section: Initial Geometry Using the Echo Defect Shape Methodsmentioning

confidence: 99%

“…First, we are performing measurements yielding experimental data, from which we are calculating an initial back wall geometry using the echo defect shape method [6]. Second, we simulate the temperature devolution (forward calculation) for the assumed structure profile by using the FEM based software COMSOL.…”

Section: Figure 1: the Complete Inversion Proceduresmentioning

confidence: 99%

Numerical method of active thermography for the reconstruction of back wall geometry

Richter¹,

Maierhofer²,

Kreutzbruck³

2012

Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography

View full text Add to dashboard Cite

show abstract

“…Currently, there exists a large amount of techniques for signal and image processing, the most relevant ones to be considered in a future standard are described in chapter 4. Data inversion is still under development, see for example [7,8].…”

Section: Development Of Standards For Active Thermography With Flash mentioning

confidence: 99%

Development of reference test specimens for the standardisation of active thermography with flash excitation

Maierhofer¹,

Reischel²,

Steinfurth³

et al. 2012

Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography

View full text Add to dashboard Cite

In this paper, results of a project concerning the development of a testing standard for active thermography with flash excitation are presented. In addition to the standardisation of the appropriate selection of equipment and procedures for testing and data analysis, the standard will describe suitable reference test specimens. These test specimens can be used for the qualification of the equipment as well as for the validation of the method including data processing concerning different areas of application.

show abstract

“…Pulsed infrared (IR) thermography is one of active IR techniques in which a surface of tested material is stimulated by a short heat pulse and the thermal response of the material is analysed [1][2][3][4][5][6][7][8][9][10][11]. The response contains information about subsurface material defects.…”

Section: Introductionmentioning

confidence: 99%

Use Of Pulsed IR Thermography For Determination Of Size And Depth Of Subsurface Defect Taking Into Account The Shape Of Its Cross-Section Area

Wysocka-Fotek¹,

Maj²,

Oliferuk³

2015

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

The paper is devoted to reconstruction of size and depth (distance from the tested surface) of artificial defects with square and rectangular cross-section areas using the pulsed IR thermography. Defects in form of flat-bottom holes were made in austenitic steel plate. The defect size was estimated on the basis of surface distribution of the time derivative of the temperature. In order to asses the depth of defects with considered geometries on the basis of calibration relations (i.e. dependence of time of contrast maximum vs. defect depth for given defect diameter) obtained for circular defects, the 'equivalent diameter' describing not only the defect cross-section area but also its shape was assigned. It has been shown that presented approach gives satisfactory results.Keywords: pulsed IR thermography, defect size, defect depth, cross-section shape of defect Praca dotyczy wyznaczania wielkości i głębokości (odległości od badanej powierzchni) symulowanych defektów o przekroju kwadratowym i prostokątnym przy użyciu impulsowej termografii podczerwieni. Defekty, w formie nieprzelotowych otworów o płaskim dnie, wykonano w blasze ze stali austenitycznej. Wielkość defektów określano analizując powierzchniowy rozkład pochodnej temperatury względem czasu.Aby wykorzystać zależności kalibracyjne (zależności czasu odpowiadającemu maksimum kontrastu temperatury od głę-bokości defektu o danej średnicy) dla defektów o przekroju kołowym do oszacowania głębokości defektów kwadratowych i prostokątnych, przyporządkowano im "ekwiwalentną średnicę" uwzględniającą nie tylko pole przekroju defektu, ale także kształt defektu. Pokazano, że dla rozpatrywanych geometrii defektów, zaproponowane podejście daje satysfakcjonujące rezultaty.

show abstract

A defect shape reconstruction algorithm for pulsed thermography

Cited by 46 publications

References 3 publications

Numerical method of active thermography for the reconstruction of back wall geometry

Numerical method of active thermography for the reconstruction of back wall geometry

Development of reference test specimens for the standardisation of active thermography with flash excitation

Use Of Pulsed IR Thermography For Determination Of Size And Depth Of Subsurface Defect Taking Into Account The Shape Of Its Cross-Section Area

Contact Info

Product

Resources

About