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thermal-instabilities
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Vibration and Buckling Analysis of Thick FGM Conical Shells Under Variable Thermal and Pressure Distributions, Considering Initial Geometric Imperfections Using a Higher Order TheoryVibration and Buckling Analysis of Thick FGM Conical Shells Under Variable Thermal and Pressure Distributions, Considering Initial Geometric Imperfections Using a Higher Order Theory
, M.Sc. Thesis Sharif University of Technology ; Dehghani Firoozabadi, Rouhollah (Supervisor)
Abstract
The current study is dedicated to free vibration and buckling analysis of thick FGM conical shells conveying hot flows with the consideration of initial geometric imperfections. To this end, the higher order governing equations of motion and the corresponding boundary conditions are derived using Hamiltonian formulations. Due to the solution procedure of Frobenius series expansion, the differential form of equations is obtained by applying by part integration to the integral form of equations of motion. Radial and longitudinal temperature distributions are considered while pressure distribution and geometric imperfection variations are found to be in longitudinal direction, only. The final...
Effect of nanostructuring on thermal stability and decomposition of aluminium titanate (Al2TiO5): a phase transformation study
, Article Materials Characterization ; Volume 173 , 2021 ; 10445803 (ISSN) ; Madaah Hosseini, H. R ; Amutha, C ; Ramakrishna, S ; Sharif University of Technology
Elsevier Inc
2021
Abstract
As a refractory ceramic, the thermal instability of aluminium titanate (AT or Al2TiO5) has been in the crosshairs of research works in recent years. The studies have indicated that different parameters such as atmosphere, grain size, additives, oxygen pressure, and synthesis method can bilaterally affect the thermal decomposition of AT ceramic and resultant physicomechanical properties. In the present study, the AT nanostructure was synthesized by a citrate sol-gel method and influence of nanostructuring nature on its thermal instability and reaction pathway was explored in some details. It was shown that the reduction of grain size down to 30 nm can destabilize AT, so that the reaction...
Thermal stability and strain sensitivity of nanostructured aluminum titanate (Al2TiO5)
, Article Materials Chemistry and Physics ; Volume 223 , 2019 , Pages 202-208 ; 02540584 (ISSN) ; Azarniya, A ; Madaah Hosseini, H. R ; Abedi, M ; Moskovskikh, D ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In the present work, nanostructured aluminum titanate (Al2TiO5 or AT) was synthesized by the sol-gel method and potential effects of mechanical strain on its phase analysis, morphology, and thermal stability were investigated in some details for the first time, because the thermal instability of AT is beneficial to the fabrication of in-situ aluminum matrix composites. To characterize the particle distribution, microstructure and thermal durability of AT after the strain induction, field-emission scanning electron microscope (FE-SEM), differential scanning calorimetry (DSC), and x-ray diffraction analysis (XRD) were utilized. The experimental results showed that a 3-h ball milling process...