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SURFACE ACOUSTIC WAVE VELOCITY MEASUREMENTS ON SURFACE-TREATED METALS BY LASER-ULTRASONIC SPECTROSCOPYRUIZ, ALBERTO 31 March 2004 (has links)
No description available.
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Nondestructive and destructive testing of covered timber bridge membersChoamnak, Sitdhichai January 1997 (has links)
No description available.
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Kartläggning av metoder inom oförstörande provning för att bedöma skicket på utrustning / Mapping of methods in non-destructive testing to assess the condition of equipmentVeittikoski, Adam, Aho, Johnny January 2021 (has links)
AstraZeneca är en av världens största tillverkare av medicin. AstraZeneca använder sig av komplexa utrustningar vid tillverkning av medicin inom sin industri. Utrustningen som rör, tankar och ventiler har en livslängd som påverkas av olika faktorer såsom värme, vibrationer eller slitage. AstraZeneca är ett företag som inte använder sig av sitt eget underhåll utan hyr in ett företag vid namn Caverion. För ett företag som AstraZeneca är det viktigt att tänka på ett underhållsperspektiv eftersom det gynnar företaget ekonomiskt. Med ett underhållstänkande kan företaget ekonomisera på mycket resurser. Det finns flera olika metoder som hjälper företaget att bespara på ekonomiska resurser. En underhållsteknik är oförstörande provning. I denna rapport undersöks olika oförstörande provningsmetoder samt hur de anpassas till optimala delar av en komponent. Denna rapport undersöker även vilken metod som används bäst mot olika komponenter och utrustning. Valet av material är även en viktig faktor som avgör vilken metod som ska användas mot vilken utrustning. Den fjärde industriella revolutionens tid nalkas och det råder mycket gott kring denna revolution. Industri 4.0 handlar om nya tekniska metoder som bland annat smarta system, vilket integreras med organisationer och operatörer. Med hjälp av nyare och smartare tekniska metoder kan man förbättra industrin till att bli mer effektiv ur ekonomi- och produktionsaspekter. / AstraZeneca is one of the world's largest manufacturers of medicines. AstraZeneca uses complex equipment when manufacturing medicine. Equipment such as pipes, tanks and valves have a service life which are affected by various factors such as heat, vibration and wear. AstraZeneca is a company that does not use its own maintenance but hires a company called Caverion. For a company like AstraZeneca, it is important to think from a maintenance perspective due to its benefits regarding the company financially. With a maintenance mindset, the company can save on a lot of resources. There are several different methods that help the company save the company on financial resources, a maintenance technique is non-destructive testing. This report describes different non-destructive test methods and how they are adapted to optimal parts of a component and also which method is best used against different components and equipment. The choice of material is also an important component in deciding which method to use for which equipment. The time of the fourth industrial revolution is approaching and this revolution is very good. Industry 4.0 is about new technical methods such as smart systems which are integrated with organizations and operators. With the help of newer, smarter technical methods, it is possible to improve the industry to become more efficient regarding economic and production aspects.
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Optical fiber modal domain sensors for dynamic strain measurementBennett, K. D. (Kimberly Dean) 16 September 2005 (has links)
Modern engineering structures often incorporate new materials and complex designs for which existing techniques for nondestructive evaluation prove inadequate, especially for dynamic and in-service measurements. At the same time, optical fiber sensors have been identified as an ideal candidate for embedded and attached measurements of material parameters such as strain, temperature, or state of damage. In particular, sensors based on optical fiber modal interference phenomena have been shown to be capable of highly sensitive detection of static and dynamic strain.
This work reviews known applications of modal domain sensing to measurement science to date, and discusses the principles behind the method. A general expression for the intensity distribution emerging from a multimode fiber is formulated, covering both few mode and highly multimode fibers, and new expressions for their sensitivity to both radial and axial strain are derived. Optimized multimode fibers are seen to show an intrinsic phase sensitivity which rivals or even surpasses that of the single mode interferometer, especially in the case of applied radial strain. The use of modal domain sensors for real-time ultrasonic wave transduction is described as a particular application to NDE, with experimental results being presented with regard to acoustic emission monitoring as well as the detection and analysis of shock waves due to impact. Finally, optimization schemes and alternatives for such sensors are addressed, and recommendations for future work are raised. / Ph. D.
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Scanning measurement testbed for advanced nondestructive evaluationHorne, Michael R. 17 January 2009 (has links)
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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Structural damage diagnosis using stereolithography, experimental modal analysis and finite element analysisAlqaradawi, Mohamed Yousef 01 October 2000 (has links)
No description available.
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Electrostatic Density Measurements in Green-State P/M PartsLeuenberger, Georg H 29 April 2003 (has links)
The goal of this research is to show the feasibility of detecting density variations in green-state powder metallurgy (P/M) compacts from surface voltage measurements. By monitoring a steady electric current flow through the sample and recording the voltages over the surface, valu-able information is gathered leading to the prediction of the structural health of the compacts. Unlike prior research that concentrated on the detection of surface-breaking and subsurface de-fects, the results presented in this thesis target the density prediction throughout the volume of the sample. The detection of density variations is achieved by establishing a correlation between the conductivity and their respective density. The data obtained from the surface measurements is used as part of an inversion algorithm, calculating the conductivity distribution, and subse-quently the density within the compact. In a first step, the relationship between conductivity and density of green-state P/M com-pacts was investigated. Tests were conducted for a number of parts of various powder mixtures. In all cases a clear correlation between conductivity and density could be established, indicating that measurements of electric conductivity could indeed be exploited in an effort to render valid information about the density of the sample under test. We found a linear correlation for non-lubricated parts and a non-linear behavior for lubricated samples. Specifically, it was found that the conductivity increases with increasing density only up to a maximum value obtained at ap-proximately 6.9g/cm3. Interestingly, any additional density increase leads to a reduction of the conductivity. This behavior was confirmed to be inherent in all powder mixtures with lubricants. The thesis research is able to provide a physical model and a mathematical formulation describ-ing this counter-intuitive phenomenon. A finite element solver in conjunction with an inversion algorithm was then implemented to study arbitrarily shaped part geometries. Based on the principles of electric impedance imag-ing, the developed algorithm faithfully reconstructs the density distribution from surface voltage measurements. The feasibility of the instrumentation approach for both simple and complex parts can be demonstrated using a new sensor concept and measurement arrangement. Measurements were performed on both geometrically simple and complex parts.
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Application of digital image correlation in material parameter estimation and vibration analysis of carbon fiber composite and aluminum platesChuang, Chih-Lan Jasmine 01 May 2012 (has links)
Identifying material parameters in composite plates is a necessary first step in a variety of structural applications. For example, understanding the material parameters of carbon fiber composite is important in investigating sensor and actuator placement on micro-air-vehicle wings for control and wing morphing purposes. Knowing the material parameters can also help examine the health of composite structures and detect wear or defects. Traditional testing methods for finding material parameters such as stiffness and damping require multiple types of experiments such as tensile tests and shaker tests. These tests are not without complications. Methods such as tensile testing can be destructive to the test specimens while use of strain gages and accelerometers can be inappropriate due to the lightweight nature of the structures.
The proposed inverse problem testing methods using digital image correlation via high speed cameras can potentially eliminate the disadvantages of traditional methods as well as determine the required material parameters including stiffness and damping by conducting only one type of experiment. These material parameters include stiffness and damping for both isotropic and orthotropic materials, and ply angle layup specifically for carbon fiber materials. A finite element model based on the Kirchoff-Love thin plate theory is used to produce theoretical data for comparison with experimental data collected using digital image correlation. Shaker experiments are also carried out using digital image correlation to investigate the modal frequencies as validation of the results of the inverse problem.
We apply these techniques first to an aluminum plate for which material parameters are known to test the performance and efficiency of the method. We then apply the method to a composite plates to determine not only these parameters, but also the layup angle. The inverse problem successfully estimates the Young's modulus and damping for the aluminum material. In addition, the vibration analysis produces consistent resonance frequencies for the first two modes for both theoretical and experimental data. However, carbon fiber plates present challenges due to limitations of the Kirchoff-Love plate theory used as the underlining theoretical model for the finite element approximation used in the inverse problem, resulting in a persistent mismatch of resonance frequencies in experimental data. / Graduation date: 2012
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Examining the quality of extruded plastic with the nondestructive testing method NAW / Examining the quality of extruded plastic with the nondestructive testing method NAWJansson, Eva, Taghavi, Seyed Saeid January 2014 (has links)
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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Preparation of X-Ray Negatives of Tree-Ring Specimens for Dendrochronological AnalysisParker, M. L., Meleskie, K. R. 11 1900 (has links)
Techniques for producing X-ray negatives of dendrochronological specimens have been developed at the Geological Survey of Canada and the Nondestructive Testing Laboratory, Mines Branch, The radiographs are produced to provide tree-ring density data to supplement ring-width measurements for dating and climatic studies. New specimen preparation techniques and X-ray methods are discussed. The quality and quantity of tree-ring information is enhanced by the use of X-ray analysis.
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