Non-destructive testing. Infrared thermographic testing. General principles for thermoelastic stress measuring method

2020 ◽  
Keyword(s):  
Thermoelastic Stress ◽  
Measuring Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Stress Measuring ◽  
Non Destructive

A thermography-based approach for structural analysis and fatigue evaluation

2011 ◽  
Vol 226 (5) ◽  
pp. 1173-1185 ◽  
Author(s):  
X G Wang ◽  
V Crupi ◽  
X L Guo ◽  
E Guglielmino
Keyword(s):  
Structural Analysis ◽  
Stress Analysis ◽  
Thermoelastic Stress ◽  
Metal Fatigue ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Fatigue Evaluation ◽  
Lock In ◽  
Short Time ◽  
Non Destructive

The infrared thermography has been developed for Non-Destructive Testing (NDT), stress analysis, and in the last 10 years for metal fatigue assessment. The present research enables to realize these different research objectives all together thanks to an innovative experimental procedure, which includes NDT by lock-in thermography, thermoelastic stress analysis, and fatigue parameters assessment by Rapid Thermographic Method ( RTM). The developed procedure has been performed on a set of hole-notched specimens, achieving good results and predictions in a relatively short time. Moreover, the fatigue strength reduction coefficients of the specimens were determined by RTM. This thermography-based approach is dedicated for structural analysis and fatigue evaluation; it is an interesting attempt to apply different thermographic methods to a common research topic.

Strain analysis by means of digital shearography: Potential, limitations and demonstration

1998 ◽  
Vol 33 (2) ◽  
pp. 171-182 ◽  
Author(s):  
W Steinchen ◽  
L X Yang ◽  
G Kupfer ◽  
P Mäckel ◽  
F Vössing
Keyword(s):  
Strain Measurement ◽  
Speckle Pattern ◽  
Strain Analysis ◽  
Measuring Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Out Of Plane ◽  
Recent Developments ◽  
Plane Displacement ◽  
Non Destructive

Shearography, also called speckle pattern shearing interferometry, is a coherent optical method which measures displacement derivatives directly. It is suited well for localization of strain concentrations and has been used as an industrial tool for non-destructive testing (NDT) in the last few years. However, its application for strain measurement has not been widely adopted in industry, because, in general, shearography can measure only out-of-plane displacement derivatives ∂w/∂x and ∂w/∂y. This paper presents recent developments of shearography for strain measurement. With the support of digital image processing the automatic and quantitative evaluation of the shearogram becomes possible. Not only flexural strains [∂2w/∂x2, ∂2w/∂y2 and ∂2w/(∂y)] but also in-plane strains (∂u/∂x, ∂v/∂y, ∂u/∂y and ∂v/∂x) can be determined by the shearographic measuring method. The potentials and limitations for strain measurement are discussed. Some applications are shown.

Nondestructive Testing of Moist Cetris-Basic Wood-Cement Chipboards by Using Impedance Spectroscopy

2015 ◽  
Vol 1124 ◽  
pp. 203-208 ◽  
Author(s):  
Miroslav Luňák ◽  
Ivo Kusák
Keyword(s):  
Impedance Spectroscopy ◽  
Water Content ◽  
Impedance Spectrum ◽  
Measuring Method ◽  
Non Destructive Testing ◽  
Inhomogeneous Materials ◽  
Destructive Testing ◽  
Stress Cycle ◽  
Non Destructive ◽  
Method Group

Impedance spectroscopy (IS) is a non-destructive testing (NDT) method ranking in the electrical engineering measuring method group. It outputs data providing information on material electric and dielectric properties. Microscopically inhomogeneous materials are frequently used in the building industry. Unfortunately, the impedance spectroscopy results and their characterization on the basis of this method are not unambiguous. The frequency spectrum behavior of Cetris-basic specimens was studied by means of the NDT impedance spectroscopy method for various water content values. A stress cycle with defined absolute water content values is described. Influences of potential dielectric losses and the predominance of the polarization and conductivity components in various regions of the impedance spectrum are described for various water content values.

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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