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Analysis of multistress ageing on dielectric spectras of materials
Kučera, Miroslav ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
Diploma thesis treat of effect of thermal, electrical and combined (thermal electrical) stress on electrical characteristics of insulation material ISONOM NMN which is used as a slot insulation in electric motors. To monitor the stress is used the method of dielectric relaxation spectroscopy. Under examinations are the resultant dielectric spectra which constitute the frequency dependencies of components of complex permitivity. Compared are the effects of particular stresses on dielectric spectra of surveyed insulative material.
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Multistress ageing analysis of the electroinsulating materials
Jeřábek, Michal ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This diploma thesis deals with not-aged and thermally, electric and multistress aged slotted isolations dielectric properities experimental probing. Dutiny experiment is watched influence moisture on dielectric properties insulating materiále ISONOMŽNMN. Especially both two permitivity complex components are surveyed, in dependence on the frequency and the temperature changes during thermal, electric and multistress ageing. These characteristics are viewed in light of application the isolation in practice.
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Safety factor evaluation for an out-of-plane frame under static loading
Málek, Michal ; Profant, Tomáš (referee) ; Burša, Jiří (advisor)
This bachelor thesis deals with evaluation of safety factor of a space frame when being statically loaded. This examination was demonstrated on a particular example. In order to solve the above mentioned, we exploit the frame symmetry. Unknown parameters were identified from deformation conditions in the point of intersection of the symmetry plane and the frame centreline, where the shift and two turning angles equal zero, and further by means of Maxwell- Mohr variant of Castigliano's theorem for determination of the frame deformation. The basis for calculations of stresses was represented by the theory of combined bar loading, particularly combination of bending and torsion. When examining the frame safety we took into consideration mainly dangerous points possibly occuring through cranks and fixed supports, where stress concentration occurs. The results of analytical solution were verified by numerical calculation in program ANSYS 10.0.
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