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NONDESTRUCTIVE TESTING METHODS AIDED VIA NUMERICAL COMPUTATION MODELS FOR VARIOUS CRITICAL AEROSPACE AND POWER GENERATION SYSTEMS
| Title: | NONDESTRUCTIVE TESTING METHODS AIDED VIA NUMERICAL COMPUTATION MODELS FOR VARIOUS CRITICAL AEROSPACE AND POWER GENERATION SYSTEMS . |
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| Name(s): |
Warren, Peter, Author Ghosh, Ranajay, Committee Chair Raghavan, Seetha, Committee CoChair Gou, Jihua, Committee Member University of Central Florida, Degree Grantor |
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| Type of Resource: | text | |
| Date Issued: | 2018 | |
| Publisher: | University of Central Florida | |
| Language(s): | English | |
| Abstract/Description: | A current critical necessity for all industries which utilize various equipment that operates in hightemperature and extreme environments, is the ability to collect and analyze data via non destructivetesting (NDT) methods. Operational conditions and material health must be constantly monitoredif components are to be implemented precisely to increase the overall performance and efficiencyof the process. Currently in both aerospace and power generation systems there are many methodsthat are being employed to gather several necessary properties and parameters of a given system.This work will focus primarly on two of these NDT methods, with the ultimate goal of contributingto not only the method itself, but also the role of numerical computation to increase the resolutionof a given technique. Numerical computation can attribute knowledge onto the governing mechanicsof these NDT methods, many of which are currently being utilized in industry. An increase inthe accuracy of the data gathered from NDT methods will ultimately lead to an increase in operationalefficiency of a given system.The first method to be analyzed is a non destructive emmision technique widely referred to asaccoustic ultrasonic thermography. This work will investigate the mechanism of heat generationin acoustic thermography using a combination of numerical computational analysis and physicalexperimentation. Many of the challenges typical of this type of system are addressed in this work.The principal challenges among them are crack detection threshold, signature quality and the effectof defect interactions. Experiments and finite element based numerical simulations are employed,in order to evaluate the proposed method, as well as draw conclusions on the viability for futureextension and integration with other digital technologies for health monitoring. A method to determinethe magnitude of the different sources of heat generation during an acoustic excitation isalso achieved in this work. Defects formed through industrial operation as well as defects formedthrough artificial manufacturing methods were analyzed and compared.The second method is a photoluminescence piezospectroscopic (PLPS) for composite materials.The composite studied in this work has one host material which does not illuminate or have photoluminescenceproperties, the second material provides the luminescence properties, as well asadditional overall strength to the composite material. Understanding load transfer between the reinforcementsand matrix materials that constitute these composites hold the key to elucidating theirmechanical properties and consequent behavior in operation. Finite element simulations of loadingeffects on representative embedded alumina particles in a matrix were investigated and comparedwith experimental results. The alumina particles were doped with chromium in order to achieveluminscence capability, and therefore take advantage of the piezospectrscopic measurement technique.Mechanical loading effects on alumina nanoparticle composites can be captured with Photostimulated luminescent spectroscopy, where spectral shifts from the particles are monitored withload. The resulting piezospectroscopic (PS) coefficients are then used to calculate load transferbetween the matrix and particle. The results from the simulation and experiments are shown tobe in general agreement of increase in load transferred with increasing particle volume fractiondue to contact stresses that are dominant at these higher volume fractions. Results from this workpresent a combination of analytical and experimental insight into the effect of particle volume fractionon load transfer in ceramic composites that can serve to determine properties and eventuallyoptimize various parameters such as particle shape, size and dispersion that govern the design ofthese composites prior to manufacture and testing. | |
| Identifier: | CFE0007262 (IID), ucf:52203 (fedora) | |
| Note(s): |
2018-08-01 M.S.M.E. Engineering and Computer Science, Mechanical and Aerospace Engineering Masters This record was generated from author submitted information. |
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| Subject(s): | Nondestructive Emission -- Acoustic Thermography -- Photoluminescence Piezospectroscopy -- Laser Ultrasonics -- Finite Element -- Nano Composite -- Computational Mechanics | |
| Persistent Link to This Record: | http://purl.flvc.org/ucf/fd/CFE0007262 | |
| Restrictions on Access: | public 2018-08-15 | |
| Host Institution: | UCF |
