Dissertations / Theses: 'Nondestructive testing'

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Haller, Kristian. "Nonlinear Acoustics Applied to NonDestructive Testing." Licentiate thesis, Karlskrona : Blekinge Institute of Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00374.

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Sensitive nonlinear acoustic methods are suitable for material characterization. This thesis describes three nonlinear acoustic methods that are proven useful for detection of defects like cracks and delaminations in solids. They offer the possibility to use relatively low frequencies which is advantageous because attenuation and diffraction effects are smaller for low frequencies. Therefore large and multi-layered complete objects can be investigated in about one second. Sometimes the position of the damage is required. But it is in general difficult to limit the geometrical extent of low-frequency acoustic waves. A technique is presented that constrains the wave field to a localized trapped mode so that damage can be located.

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2

Rudraraju, Sridhar. "Fiber optic methods for nondestructive testing." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-01102009-063839/.

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3

Pardoe, Andrew Charles. "Neural network image reconstruction for nondestructive testing." Thesis, University of Warwick, 1996. http://wrap.warwick.ac.uk/44616/.

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Conventional image reconstruction of advanced composite materials using ultrasound tomography is computationally expensive, slow and unreliable. A neural network system is proposed which would permit the inspection of large composite structures, increasingly important for the aerospace industry. It uses a tomographic arrangement, whereby a number of ultrasonic transducers are positioned along the edges of a square, referred to as the sensor array. Two configurations of the sensor array are utilized. The first contains 16 transducers, 4 of which act as receivers of ultrasound, and the second contains 40 transducers, 8 of which act as receivers. The sensor array has required the development of instrumentation to generate and receive ultrasonic signals, multiplex the transmitting transducers and to store the numerous waveforms generated for each tomographic scan. The first implementation of the instrumentation required manual operation, however, to increase the amount of data available, the second implementation was automated.

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4

Liu, Zheng. "Studies on Data Fusion of Nondestructive Testing." Kyoto University, 2000. http://hdl.handle.net/2433/180956.

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本文氏名 : 刘(劉) 征
Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第8362号
工博第1927号
新制||工||1171(附属図書館)
UT51-2000-F266
京都大学大学院工学研究科資源工学専攻
(主査)教授花崎紘一, 教授英保茂, 教授芦田讓
学位規則第4条第1項該当

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5

Imbert, de Smirnoff Severine. "Nondestructive Flaw Characterization in a Unidirectional Composite Plate." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/ImbertdeSmirnoffS2002.pdf.

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6

Ho, Andy C. "Quantification of gamma-ray Compton-scatter nondestructive testing." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0021/MQ54625.pdf.

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7

Tant, Katherine M. M. "Time-frequency domain modelling for ultrasonic nondestructive testing." Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24448.

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This thesis endeavours to develop and implement new and improved methods for the characterisation of defects embedded in steel welds through the analysis of data collected by ultrasonic phased array inspections. A factor common to the existing imaging techniques used for flaw characterisation is the subjective thresholding required to estimate the size of the flaw. The work contained in this thesis uses the mathematics of inverse problems and scattering theory to extract information about such defects and puts forward an objective approach which employs a mathematical model. A relationship between the pulse-echo response curve of a scattering matrix and the size and orientation of a flaw is derived analytically via the Born approximation and results in a completely objective approach to crack sizing. Further expansion of these relationships allows for expressions to be formulated concerning the minimum resolvable crack length and the effects of array pitch and flaw depth on the accuracy of the algorithm. The methodology is then extended and tested on experimental data collected from welded austenitic steel plates containing a lack of fusion crack. In the latter part of this thesis, work focusses on the exploration of the fractional Fourier transform and coded excitations. The fractional Fourier transform allows for retention of both time and frequency domain information simultaneously and permits the in homogeneous wave equation (with a forcing function prescribed as a linear chirp modulated by a Gaussian envelope) to be solved in time-frequency space. This in turn facilitates a comparison between a gated continuous wave excitation and a Gaussian modulated linear chirp. It is observed that the Gaussian modulated linear chirp results in a marked increase in the scattering amplitude.

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Alleyne, David N. "Nondestructive testing of plates using ultrasonic Lamb waves." Online version, 1991. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.263143.

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9

Horne, Michael R. "Scanning measurement testbed for advanced nondestructive evaluation." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/30979.

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New materials and manufacturing processes, and the quest for economy and user safety, have necessitated the development of nondestructive testing methods to quantify the life and reliability of a product during manufacture and service. Described herein, is a testbed to be used in the research and development of these testing methods. A brief motivation for using ultrasonics applied to nondestructive evaluation is followed by a chapter on the feasibility of using a unique testing method and animated data presentation on advanced composite materials. This testing method, conceived by the author, utilizes oblique injection of ultrasound into the specimen. Several cycles of the ultrasonic waveform radiated from the specimen downstream of the injection area is digitized and recorded. The data has three independent dimensions; cartesion location and time. The time variable is the key to the presentation of the data as an animated two dimensional image. It was this work that illustrated the need for a flexible scanning imaging research testbed, not only for the discussed method, of which it is an integral part, but for advanced development of other techniques. Software development and integration of off -the-shelf parts into a unified computer controlled testing facility is the contribution by the author in the second phase of this research. Chapters on the description of the system, an example showing the capabilities of the system analogous to traditional ultasonic C-scanning, accomplishments, and a look to the future conclude this thesis. The appendices include listings of the programs developed for the system, a manufacturer address list. A videotape of the animation data presentation is included as a second volume of this thesis.
Master of Science

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10

Choamnak, Sitdhichai. "Nondestructive and destructive testing of covered timber bridge members." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177444570.

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11

Rhodes, Patrick Bryan. "Nondestructive assessment of pile tip elevations." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/20963.

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Drinkwater, Bruce Walton. "The use of dry coupling in ultrasonic nondestructive testing." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296521.

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Holford, K. M. "The nondestructive testing of wire ropes by acoustic emission." Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378397.

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Johnson, Jay Tillay. "Defect and thickness inspection system for cast thin films using machine vision and full-field transmission densitometry." Thesis, Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37234.

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Quick mass production of homogeneous thin film material is required in paper, plastic, fabric, and thin film industries. Due to the high feed rates and small thicknesses, machine vision and other nondestructive evaluation techniques are used to ensure consistent, defect-free material by continuously assessing post-production quality. One of the fastest growing inspection areas is for 0.5-500 micrometer thick thin films, which are used for semiconductor wafers, amorphous photovoltaics, optical films, plastics, and organic and inorganic membranes. As a demonstration application, a prototype roll-feed imaging system has been designed to inspect high-temperature polymer electrolyte membrane (PEM), used for fuel cells, after being die cast onto a moving transparent substrate. The inspection system continuously detects thin film defects and classifies them with a neural network into categories of holes, bubbles, thinning, and gels, with a 1.2% false alarm rate, 7.1% escape rate, and classification accuracy of 96.1%. In slot die casting processes, defect types are indicative of a misbalance in the mass flow rate and web speed; so, based on the classified defects, the inspection system informs the operator of corrective adjustments to these manufacturing parameters. Thickness uniformity is also critical to membrane functionality, so a real-time, full-field transmission densitometer has been created to measure the bi-directional thickness profile of the semi-transparent PEM between 25-400 micrometers. The local thickness of the 75 mm x 100 mm imaged area is determined by converting the optical density of the sample to thickness with the Beer-Lambert law. The PEM extinction coefficient is determined to be 1.4 D/mm and the average thickness error is found to be 4.7%. Finally, the defect inspection and thickness profilometry systems are compiled into a specially-designed graphical user interface for intuitive real-time operation and visualization.

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15

Sanderson, Terry. "Thermoelastic modeling of laser generated ultrasound for nondestructive materials testing." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/18978.

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Gadyuchko, Andrey, and Sören Rosenbaum. "Nondestructive quality inspection of solenoid valves." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200756.

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The presented innovative magnetic testing method utilises the fact, that each commercially available electromagnet can not only be used as an actuator, but also comprises internal sensor functions. This allows a huge application variety in the fields of non-destructive testing and condition monitoring of electromagnetic systems during production and within the application in the field.

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Chan, Tony T. T. "Ultrasonic method of non-destructive test in metals effects of grain size on ultrasound wave at various frequencies /." access abstract and table of contents access full-text, 2006. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21456276a.pdf.

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Thesis (M.Sc.)--City University of Hong Kong, 2006.
"Master of Science in Materials Engineering & Nanotechnology dissertation." Title from title screen (viewed on Nov. 21, 2006) Includes bibliographical references.

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Round, Robert. "Evaluation of reaction kinetics and material properties of cementitious ceramic materials using ultrasonic velocity and attenuation measurements." Thesis, Brunel University, 1996. http://bura.brunel.ac.uk/handle/2438/6512.

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Ultrasonic velocity and attenuation measurements have been used to characterise a range of phosphate bonded, alumina filled, magnesia ceramics and other ceramic materials... Measurements were made over a range of frequency from 50kHz - 1 OM Hz, using a variety of commercial probes and equipment, and a variety of techniques. An ultrasonic double-probe method was used to monitor the setting process of the cementitious ceramics using commercial 2.25MHz and 2MHz transducers, for compressional and shear wave modes, respectively, in samples with alumina content in the range of 0 - 60 wt 0/0. The elastic properties of the material were determined from ultrasonic velocity measurements and were found to be dependent upon the filler volume fraction. The measured elastic moduli were found to Increase as porosity decreased, and this effect might possibly be used to estimate porosity. The composition dependence of the elastic moduli is compared with the Hashin and Shtrikman theoretical bounds for the elastic moduli of two-phase materials. All data lie between these bounds, suggesting that the alumina particles were well dispersed and well bonded to the matrix. However, the fact that the data are slightly above the lower bound suggested that the particles are not spherical, and this, together with other evidence obtained from an analysis of reaction rates, indicates the predominence of plate-like gram structures.

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19

Ayra, Behnam. "Structural identification for condition assessment using modal non-destructive test data /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2000.

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Thesis (Ph.D.)--Tufts University, 2000.
Adviser: Masoud Sanayei. Submitted to the Dept. of Civil Engineering. Includes bibliographical references (leaves 152-159). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

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20

Wilkinson, Gordon Peter. "An integrated wide bandwidth ultrasonic signal acquisition instrument." Thesis, Keele University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385557.

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A wideband digital signal acquisition instrument intended primarily for ultrasonic experimentation has been designed and built. It comprises an integrated array of modules which combine to provide: a pulser for transducer excitation, wideband amplification (>80 MHz bandwidth), high speed sampling (>160 MHz), on-board memory (4K x 16 bits capacity), control hardware and real-time coherent averaging. The integration of the modules offers significant benefits over systems consisting of a number of separate items of equipment. The major benefit is a reduction in acquisition time which is accomplished as follows. The time relationship between the sampling clock and the input signal is controlled to minimise the signal repetitions required for interleaving. This is achieved by triggering the input signal using a pulser board locked to the sample clock. In addition, signal averaging is implemented in hardware using two memory modules and an adder module. Since the time relationship between the sampling clock and the input signal is controlled it cannot be tested using a sinewave because it is not possible to produce a sinewave which is correlated with the sampling clock. Instead, a rectangular pulse, triggered by the instrument, is applied to a single-pole low pass filter to provide the test signal. The time constant and start time is ascertained and used to reproduce the single-pole response. The reproduced response is then compared to the sampled signal to produce an error plot from which the system's linearity and effective bits can be deduced. As the system was designed for fast acquisition, and hence has a short aperture time, it is highly applicable to dynamic processes. The dynamic process application chosen was the measurement of absorption and velocity on rapidly flocculating and sedimenting colloids.

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21

Newtson, Craig M. "Reconstruction algorithms to improve nondestructive evaluation of reinforced concrete /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/10114.

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22

Dupuis, Kenneth J. "Nondestructive testing of concrete box girder bridges using thermal imaging." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Spring2008/K_Dupuis_040908.pdf.

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23

Schmarje, Nicole. "Lithium niobate piezocomposites for high temperature applications in nondestructive testing." Thesis, University of the West of Scotland, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427710.

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24

Cumming, Scott Russell. "Nondestructive testing to monitor concrete deterioration caused by sulfate attack." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004740.

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25

Jansson, Eva, and Seyed Saeid Taghavi. "Examining the quality of extruded plastic with the nondestructive testing method NAW." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2683.

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Defects in a plastic floor material produced in Tarketts factory in Ronneby are causing waste of time and material since it is noticed too late in the production line. The objective of this thesis is to investigate if the nondestructive test method NAW®, which is developed by Acoustic Agree in Ronneby, can be a solution to find the defects at an earlier stage. Nondestructive testing mainly means what the name says; quality tests of a material can be made without causing any damage. One simple example of a nondestructive testing tool is the human eye. By looking at a product defects on the surface can be found. The method used in this thesis, NAW®, is a nonlinear acoustical method. By listening to the material, information about disturbances inside the material can be gathered and interpreted to get a picture of the quality status. Although by listening it does not in this case mean by a human ear but with special equipment since the sound used is high frequent ultrasound. For several material samples, experiments were made both for the references and with introduced defects. It was hard to get definitive results since, for example, even the results for the different reference samples were differing a lot. Nevertheless there are some results pointing in the same direction which means that there is still hope for the possibility to use NAW® as a tool in the production at Tarkett. One important problem in this work is the fact that the defect material is not actually a real defect material but an imitated one with defects made by hand in the experiments. This is a possible error and has to be considered in case of further experiments. Either the imitated defects have to be “improved” or, in the ideal case, real defective material from the factory should be used to get as reliable results as possible.
Defekter i golvmaterial i tillverkningen hos Tarkett i Ronneby orsakar slöseri med tid och material eftersom de upptäcks sent i produktionslinjen. Syftet med detta examensarbete är att undersöka om den oförstörande provningsmetoden NAW®, som utvecklats av Acoustic Agree i Ronneby, kan vara en lösning för att hitta defekterna på ett tidigare stadium. Oförstörande provning är helt enkelt materialprovning där föremålet som undersöks inte förstörs. Ett enkelt exempel på verktyg för oförstörande provning är ögat. Genom att undersöka ett föremål med synen kan man enkelt kvalificera ytan. Den metod som används i detta arbete, NAW®, är en olinjär akustisk metod. Genom att lyssna på materialet kan mycket information om störningar inuti materialet samlas ihop och tolkas för att få en bild av kvaliteten. För flera materialbitar har experiment genomförts både för referensmaterial och för material med imiterade defekter. Det var svårt att se entydiga resultat då exempelvis till och med resultaten för referensmaterialet var väldigt olika sinsemellan. Dock pekar vissa av resultaten åt samma håll vilket gör att hoppet lever kvar för att NAW® kan vara ett möjligt verktyg i produktionen hos Tarkett. Ett stort problem i arbetet var frånvaron av trovärdiga defekter. Defekterna tillverkades och introducerades i materialet för hand, och viss tveksamhet finns gällande likheten mellan imiterade och riktiga defekter. Detta ses som en möjlig felkälla och måste tas i beaktan för eventuellt fortsatt arbete. Antingen måste de imiterade defekterna ”förbättras” eller, som vore idealt, så kan riktigt defekt material från tillverkningen användas för att ge så trovärdiga och pålitliga resultat som möjligt.

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Lee, Jeffrey Allen. "Nondestructive evaluation of reinforced concrete via infrared thermography: a feasibility study." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41987.

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An experimental investigation was conducted to develop a laboratory technique for the nondestructive evaluation of reinforced concrete. The methodologies were developed with the intent of eventual field implementation to determine the feasibility of utilizing infrared thermography to inspect substructural elements of concrete bridges.

Several specimen configurations were fabricated for thermographic inspection. A number of tests were performed on a variety of concrete specimens to determine the implementation parameters of the technique. The necessity of utilizing artificial heating methods for thermal input prior to inspection was evaluated.

The present study suggests that infrared thermography cannot be applied to substructural elements of bridges in a noncontact fashion. Internal thermal gradients produced by diurnal temperature fluctuation generally are not sufficient to produce the variations in surface temperature patterns necessary for thermographically detecting nonvisual subsurface defects. Rather, both the envelopment and artificial heating of the substructural element is required prior to thermographic inspection.

Master of Science

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27

Bangalore, Gurudutt S. "Nondestructive evaluation of FRP composite members using infrared thermography." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2419.

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Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains viii, 101 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-101).

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Kmack, Richard Matthew. "Characterization of air voids in fresh cement paste through ultrasonic nondestructive testing." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24794.

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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Jacobs, Laurence; Committee Co-Chair: Kurtis, Kimberly; Committee Member: DesRoches, Reginald.

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Costley, R. Daniel Jr. "Laser generation of Rayleigh and Lamb waves for ultrasonic nondestructive testing." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/17627.

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30

Wang, Jianmin. "A study of optical and opto-electronic techniques for nondestructive testing." Thesis, Heriot-Watt University, 1992. http://hdl.handle.net/10399/1495.

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31

Hohmann, Brian P. (Brian Patrick). "Life extension of structural components via an improved nondestructive testing methodology." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62688.

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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 337-355).
An experimental study was performed to determine the flaw detection sensitivity of advanced nondestructive testing (NDT) techniques with respect to structural applications. The techniques analyzed exemplify the incorporation of digital technology into NDT and includes the following: meandering winding magnetometer array (MWM-array@) eddy current, phased-array ultrasonic (PA-UT), three dimensional computed tomography (3DCT), and digital radiography (DR). The three classes of samples inspected with these techniques consisted of alloy block specimens containing flat bottom hole (FBH) arrays, probability of detection (POD) wedding cake samples, and actual airplane engine components. Results from the sensitivity analyses were compared to current NDT techniques used industrially. An image analysis program called Cellprofiler was used to optimize the threshold correction factor for selected results. The Cellprofiler output was analyzed in conjunction with POD software, and the integration of digitally advanced NDT techniques with image analysis software resulted in approximately a threefold improvement in the minimum detectable flaw size at the 90/95 POD/CL level. An improved inspection methodology was presented which incorporated redundancy in the in-service inspection plan with the use of Bayesian updating techniques to forecast remnant life. Reliability block diagrams for structural disk and blade aircraft engine components were presented as examples of the methodology. Implementation of the proposed NDT methodology significantly increases the feasibility of a retirement-forcause (RFC) approach to be applied to aging structural components in a cost-effective manner.
by Brian P. Hohmann.
Sc.D.

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Clay, Arthur C. (Arthur Chisholm) 1971. "Development and experimental characterizaton of ultrasonic phased arrays for nondestructive testing." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/10032.

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Choudhary, Vipin. "Nondestructive testing and antenna measurements using UWB radar in industrial applications." Licentiate thesis, KTH, Teknisk informationsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291129.

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Many industries are rapidly substituting the manual test operations and move towards automated operations using modern technologies.Modern technologies such as digital cameras, sonic sensors, infrared sensors, and radar and lidar systems are used for non-destructive testingoperations. Among all the different sensors, radar systems have theability to penetrate built structures (dielectric materials), which makes them flexible and suitable for a wide range of industrial and military applications in non-destructive sensing. Such examples are the detection of damages in goods manufacturing, monitoring the health of manystructures, object detection through the wall for security purposes, etc.In particular, ultra-wide-band (UWB) radar systems are beneficial inproviding high measurement accuracy and simultaneously reduced sensitivityto passive interference (such as rain, smoke, mist etc.), immunity to external radiation and noise.The objectives of this thesis are: I) to investigate electrically small concealed structures using synthetic aperture radar (SAR), II) to determinethe complex refractive index of objects using an UWB radar system,and III) to answer to the question how we can reduce the mutual coupling (cross talk) in an UWB radar system with collocated transmitand receive antennae. In objective I, the aim is non-destructive testing of built structures, such as in concrete slab manufacturing or for use in the renovation process. In addition electrically small periodic meshes,and their orientation, could not be distinguished in conventional SAR images. The proposed polarimetric analysis method demonstrates the usefulness of the singular value decomposition (SVD) using back projection algorithm (BPA) in extracting information about shape and for classifying an electrically small object. Further in this thesis for objective II, a new method for determining the complex refractive index (or equivalently the complex relative permittivity) of objects with planar interfaces is presented. The proposed method is relatively insensitive to hardware-impairments such as frequency-dependence of antennas and analog front end. The objects can be finite in size and at a finite distance. The limits in size and distance for the method to be valid are experimentally investigated. Hence, the method is designed for industrial in-line measurements onobjects on conveyor belts. Furthermore, in the following parts of this thesis −objective III− we investigate and show how a microwave metamaterial based absorber can be used to improve the performance of aradar system for short range applications, when positioned between the transmit and receive antennas. As results, the error in estimated target distance is reduced and clutter reduction is improved.
Många branscher ersätter snabbt de manuella testoperationerna och går mot automatiserad drift med modern teknik. Modern teknik såsom digitalkameror, soniska sensorer, infraröda sensorer och radar och lidarsystem används för i icke-förstörande tester. Bland alla olika sensorerhar radarsystem förmågan att tränga igenom byggda strukturer (dielektriskmaterial), vilket gör dem flexibla och lämpliga för ett brettspektrum av industriella och militära applikationer vid icke-förstörande avkänning. Sådana exempel är upptäckt av skador vid tillverkning av varor, övervakning av hälsa hos många strukturer, detektering av objekt genom väggen av säkerhetsskäl etc. Speciellt är radarsystem med ultrabredband (UWB) fördelaktiga då de ger hög mätnoggrannhet och samtidigt minskad känslighet mot passiva störningar (såsom regn, rök,dimma etc.), och immunitet mot yttre strålning och buller. Syftet med denna avhandling är : I) att undersöka elektriskt små dolda struktur med syntetisk bländaradar (SAR), II) att bestämma komplex brytningsindex för objekt som använder UWB radarsystem, ochIII) att svar på frågan hur vi kan minska den ömsesidiga kopplingen(överhörning) i ett UWB radarsystem med sändar- och mottagarantenner nära varandra. I mål I, är målet icke-förstörande provning avbyggda struktures såsom vid tillverkning av betongplattor eller vid renovering. I tillägg kunde inte elektriskt små strukturer och deras inre struktur urskiljas i konventionella SAR-bilder. Den föreslagna polarimetriskaanalysmetoden visar på hur användbar singulärvärdesuppdelning(SVD) med bakåtprojektion (BPA) är för att få information om och för att klassificera elektriskt små objekt.Vidare i denna avhandling visas för mål II en ny metod för att bestämma komplexa brytningsindex (eller motsvarande komplexa relativa permittiviteten) hos objekt med plana ytor. Den föreslagna metoden är relativt okänslig för svagheter hos hårdvaran, såsom frekvensberoende hos antennener och analog front-end. Objekten kan vara av ändlig storlek och på ändligt avstånd. Begränsningarna i storlek och avstånd för metoden att vara giltig undersöktes experimentellt. Sålunda är metoden utformad för industriella mätningar på föremål på transportband. I de följande delarna av avhandlingen - mål III - undersöker och visar vi dessutom hur en absorbator för mikrovågor, baserad på metamaterial, kan användas för att förbättra prestanda hos ett radarsystem för korta avstånd, när absorbatorn placeras mellan sändar- och mottagantenner. Resultatet blir att felet i det bestämda avståndet till målet minskar och undertryckning av klotter ökar.

QC 20210309

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Hasar, Ugur Cem. "Microwave nondestructive testing and evaluation of electrical properties of lossy materials." Diss., Online access via UMI:, 2008.

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Thesis (Ph. D.)--State University of New York at Binghamton, Department of Electrical and Computer Engineering, Thomas J. Watson School of Engineering and Applied Science, 2008.
Includes bibliographical references.

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Wissawapaisal, Komwut. "Nondestructive testing of reinforced and prestressed concrete structures using acoustic waveguides." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2049.

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Thesis (Ph. D.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains xiv, 204 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 190-195).

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Bram, Justin Gary. "A "divide and conquer" strategy for NDE signal inversion in gas transmission pipelines /." Full text available online, 2006. http://www.lib.rowan.edu/find/theses.

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Kuper, Alan Benjamin. "Detection of delaminations of FRP retrofitted reinforced concrete columns." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/a_kuper_111909.pdf.

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Thesis (M.S. in civil engineering)--Washington State University, December 2009.
Title from PDF title page (viewed on Dec. 28, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 51).

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Jama, Bandile, Jasson Gryzagoridis, and Graham Wilson. "Aspects of thermography for non-destructive testing in mechanical maintenance." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2579.

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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017.
Infrared thermography (IRT) is a non-contacting, non-destructive testing (NDT) technique that provides relatively fast results from inspections; for example, in the detection of defects in engineering components and in systems' condition monitoring. This study examines the use and possible effectiveness of infrared thermography for the detection of faults and defects in just a few aspects that one encounters in the vast mechanical maintenance arena. The study discusses three aspects of infrared thermography, namely internal leaks inspections using passive infrared thermography, pulse thermography and induction thermography both active IRT NDT techniques for the detection of subsurface and surface defects. The promising results that were obtained by performing an experiment in the laboratory using a model fluid handling pipe network, with three isolation valves connected in parallel, encouraged performing inspections in an operating power plant, where it was suspected that there were leaks from safety and drain isolation valves. In both situations, the results were obtained in a short period of time and indicated that passive infrared thermography can detect internal leaks in pipe networks. Pulsed thermography is an active non-contacting non-destructive testing technique used to detect subsurface defects in monolithic materials and delamination's in composites. In the particular experiment that was performed pulse thermography was benchmarked with the conventional technique of ultrasound testing. PVC, stainless steel and mild steel specimens manufactured with flat bottom holes (as models of subsurface defects) were subjected to pulse thermography. The time duration to detect the presence of a defect represented by a temperature contrast or a hot spot on the specimen's surface was approximately a couple of seconds following the thermal excitation. No further characterization of the defect was possible with the technique. In contrast when using the ultrasound testing technique to test the specimens, it took considerable time to detect the defects, however, data in terms of size and depth beneath the surface became available thus enabling their full characterization.

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Chan, Denny Yuk. "Structural integrity assessment of cantilevered type concrete structures by instrumented impact hammer (IIH) technique & ultrasonic pulse velocity (UPV) technique." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21174088a.pdf.

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Thesis (M.Sc.)--City University of Hong Kong, 2005.
At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Aug. 31, 2006) Includes bibliographical references.

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Lau, Connie K. Y. "Non-destructive evaluation with ultrasonic pulse velocity (UPV) in concrete structure." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21174441a.pdf.

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Thesis (M.Sc.)--City University of Hong Kong, 2005.
At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 1, 2006) Includes bibliographical references.

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Mong, Seng Ming. "Non-destructive evaluation with ultrasonic pulse velocity (UPV) in concrete structure." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21175032a.pdf.

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Thesis (M.Sc.)--City University of Hong Kong, 2005.
At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.

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Andary, Elie George. "Evaluating nondestructive testing techniques to detect voids in bonded post-tensioned ducts." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001074.

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Lewis, Adam Miles. "The modelling of electromagnetic methods for the nondestructive testing of fatigue cracks." Thesis, University College London (University of London), 1991. http://discovery.ucl.ac.uk/1317503/.

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This thesis describes a theoretical and experimental investigation of electromagnetic methods for the detection and measurement of metal fatigue cracks. The available methods are reviewed, with particular attention being paid to mathematical models, and a new model of the electromagnetic field near a metal fatigue crack for small skin-depths is presented which uses a surface impedance boundary condition with the addition of a line source to represent the crack. This leads to a coupled system of two magnetic scalar potentials, one on the crack face which obeys the two-dimensional Laplace equation and one outside the test-piece which obeys the three-dimensional Laplace equation. The behaviour of the field is governed by a parameter m =l/(μ, δ), where l is the size of the field perturbation, μ, is the relative permeability and δ is the skin-depth. When m is small, almost all the flux is concentrated inside the metal and the exterior potential also obeys the two-dimensional Laplace equation, on the test-piece surface. When m is large, the perturbation part of the exterior field has a negligible effect on the field inside the crack so that the crack-face potential may be found by the Born approximation. The general m problem is solved for rectangular and semi-elliptical cracks in flat plates, interrogated by uniform fields, and the solution is verified experimentally. A method for calculating the crack depth from the magnetic field is given, with descriptions of industrial applications. The theory is further developed to find the impedance change in an air-cored circular coil caused by a crack, to find the field near overlapping cracks and to find the field near a crack in an interior corner. Finally, a semi-empirical analysis is presented for a ferrite-cored measuring coil.

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Thomas, Anton F. (Anton Felipe) 1977. "Anomaly edge effects in thermographic nondestructive testing of polymeric composite sandwich panels." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/89365.

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Kurra, Sri Harsha. "Nondestructive testing for finding out the displacement of crack in silicon nitride." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

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Hughes, Mary Leigh. "Nondestructive determination of unknown pile tip elevations using modal analysis." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/30900.

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Fattahi, Seyed Javad. "Locomotion and Morphing of a Coupled Bio-Inspired Flexible System: Modeling and Simulation." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32827.

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The thesis focused on the development and analysis of a distributed parameter model that apply to a class of an autonomous hyper-redundant slender robotic systems interacting with the environment. The class of robotic devices that will be implemented based on the modelling in this thesis, is intended to be autonomously deployed in unknown, unstructured environments, in which it has to accomplish different missions by being able to robustly negotiate unknown obstacles and unpredictable and unmodelled irregularities. Therefore the mechanical models presented here are inspired by some features of a class of organisms - millipedes and centipedes - that possess many of these capabilities. Specifically, these organisms posses flexible slender bodies whose shape morphs according to the curvature of the terrain on which they operate, and possess a highly redundant system of legs that couple the body with the terrain providing propulsion for forward or backward motion, with the high number of legs ensuring a robust distributed contact even on very irregular substrates. The mechanical model that naturally captures the structure of millipede bodies is the Timoshenko beam, which is therefore adopted here. Moreover, the coupling with the environment is modeled by a system of compliant elements, that provides a distributed support analogous to the one exerted by millipedes' legs; such support provides a distributed force that in a control framework is treated as the actuation for shape morphing, so that the body of the system deforms according to the curvature of the substrate. By using a Lagrangian mechanics approach, the evolution of the system is described in a suitable product Hilbert space, in which rigid body degrees of freedom and deformations are coupled. This formulation allows to pose a distributed parameter control problem in which shape morphing and locomotion are dictated by the interaction with the substrate, which in this case is approximated as rigid (that is, the profile of the substrate is not affected by the interaction with the system). Additionally, by modeling the material response of the substrate with a simple linear viscoelastic model, we pose an estimation problem in which, by measuring deformations and/or stresses on the body represented by the beam, we can infer the material properties of the substrate. In this case, the overall coupled system is modelled as a beam on a multi-layer viscoelastic foundation. Predictions of this sensor model are in good agreement with published results, suggesting that the system can be used in a versatile way as an autonomous agent operating in a generic environment, and simultaneously as a sensor that could inform the action of the system itself, or that could be used to monitor the environment. The modeling work done in this study opens the possibility for the implementation in engineering systems applied to environmental monitoring and health applications, in which we envision the system to be used to estimate material properties of living tissues, that can be correlated to the diagnosis of classes of diseases.

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Aflaki, Beni Aman. "35-45 giga hertz transceiver system for phase and magnitude detection." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Aman_aflaki_Final_thesis_09007dcc8034dd48.pdf.

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Thesis (M.S.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 14, 2007) Includes bibliographical references (p. 118-119)

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廖威賢 and Wai-yin Liu. "Ultrasonic reflection tomography over circular aperture." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31210910.

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Duan, Yuxia. "Probability of detection analysis for infrared nondestructive testing and evaluation with applications including a comparison with ultrasonic testing." Doctoral thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25251.

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La fiabilité d'une technique d’Évaluation Non-Destructive (END) est l'un des aspects les plus importants dans la procédure globale de contrôle industriel. La courbe de la Probabilité de Détection (PdD) est la mesure quantitative de la fiabilité acceptée en END. Celle-ci est habituellement exprimée en fonction de la taille du défaut. Chaque expérience de fiabilité en END devrait être bien conçue pour obtenir l'ensemble de données avec une source valide, y compris la technique de Thermographie Infrarouge (TI). La gamme des valeurs du rapport de l'aspect de défaut (Dimension / profondeur) est conçue selon nos expériences expérimentales afin d’assurer qu’elle vient du rapport d’aspect non détectable jusqu’à celui-ci soit détectable au minimum et plus large ensuite. Un test préliminaire est mis en œuvre pour choisir les meilleurs paramètres de contrôle, telles que l'énergie de chauffage, le temps d'acquisition et la fréquence. Pendant le processus de traitement des images et des données, plusieurs paramètres importants influent les résultats obtenus et sont également décrits. Pour la TI active, il existe diverses sources de chauffage (optique ou ultrason), des formes différentes de chauffage (pulsé ou modulé, ainsi que des méthodes différentes de traitement des données. Diverses approches de chauffage et de traitement des données produisent des résultats d'inspection divers. Dans cette recherche, les techniques de Thermographie Pulsée (TP) et Thermographie Modulée(TM) seront impliquées dans l'analyse de PdD. Pour la TP, des courbes PdD selon différentes méthodes de traitement de données sont comparées, y compris la Transformation de Fourier, la Reconstruction du Signal thermique, la Transformation en Ondelettes, le Contraste Absolu Différentiel et les Composantes Principales en Thermographie. Des études systématiques sur l'analyse PdD pour la technique de TI sont effectuées. Par ailleurs, les courbes de PdD en TI sont comparées avec celles obtenues par d'autres approches traditionnelles d’END.
The reliability of a Non-Destructive Testing and Evaluation (NDT& E) technique is one of the most important aspects of the overall industrial inspection procedure. The Probability of Detection (PoD) curve is the accepted quantitative measure of the NDT& E reliability, which is usually expressed as a function of flaw size. Every reliability experiment of the NDT& E system must be well designed to obtain a valid source data set, including the infrared thermography (IRT) technique. The range of defect aspect ratio (Dimension / depth) values is designed according to our experimental experiences to make sure it is from non-detectable to minimum detectable aspect ratio and larger. A preliminary test will be implemented to choose the best inspection parameters, such as heating energy, the acquisition time and frequency. In the data and image processing procedure, several important parameters which influence the results obtained are also described. For active IRT, there are different heating sources (optical or ultrasound), heating forms (pulsed or lock-in) and also data processing methods. Distinct heating and data processing manipulations produce different inspection results. In this research, both optical Pulsed Thermography (PT) and Lock-in Thermography (LT) techniques will be involved in the PoD analysis. For PT, PoD curves of different data processing methods are compared, including Fourier Transform (FT), 1st Derivative (1st D) after Thermal Signal Reconstruction (TSR), Wavelet Transform (WT), Differential Absolute Contrast (DAC), and Principal Component Thermography (PCT). Systematic studies on PoD analysis for IRT technique are carried out. Additionally, constructed PoD curves of IRT technique are compared with those obtained by other traditional NDT& E approaches.

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Dissertations / Theses on the topic 'Nondestructive testing'

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