Aeroelastic tailoring of oscillating supersonic wing /
One of the most dangerous aeroelastic failure phenomenons is flutter. The flutter characteristic is different for each type of aircraft depends on the wing geometry and its operational region of subsonic, transonic or supersonic. Prior to performing flight flutter test, extensive numerical simulatio...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur :
Kulliyyah of Engineering, International Islamic University Malaysia,
2014
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | One of the most dangerous aeroelastic failure phenomenons is flutter. The flutter characteristic is different for each type of aircraft depends on the wing geometry and its operational region of subsonic, transonic or supersonic. Prior to performing flight flutter test, extensive numerical simulations and Ground Vibration Test should be conducted where the structural finite element modes and the experimentation results should be matched otherwise the numerical simulation model could be rejected. In the present work, the simulation of supersonic wing equipped with external stores of missiles on the wing had been analyzed at high supersonic region. The structural mode shapes at each generated frequency mode are also visually presented. The analysis is carried out using FEM software of MSC Nastran. The wing flutter with the external stores has been simulated at different altitudes. The result shows that the flutter velocity is sensitive to the flight altitude. For this reason, the flutter analysis is conducted also for a negative altitude. The negative altitude is obtained by considering the constant equivalent speed-Mach number rule at flutter speed boundary as a requirement in standard regulation of transport aircraft. The achieved flutter speed results at all altitudes have been set as the constraint to perform an optimization about the wing weight. The optimization processes have been performed by replacing the aluminum skin of the wing with Kevlar/Epoxy composite using steepest descent method. There are 5 processes of simulation have been performed by reducing the skin thickness respectively and observing the changes of flutter speed at every altitude. The results of weight reduction of the wing skins, the wing structure, and the whole weight for operation have been presented using graphical method. Further reduction of weight have been studied by reducing the ribs thickness of each region with condition the flutter speed of the case study should not below the baseline flutter speed results. The final result of Kevlar/Epoxy composite skin wing shows that the clean wing weight using composite can be reduced about 56.3% compared to the baseline. The final analysis of Kevlar/Epoxy composite skin wing continues by replacing the composite material with Graphite/Epoxy composite skin to study the effect of high modulus of elasticity of the present wing. The final result of this analysis shows that the weight of the clean wing can be reduced about 62% with higher flutter speed achieved compared to the baseline. |
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| Item Description: | Abstracts in English and Arabic. |
| Physical Description: | xviii, 125 leaves : ill. ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 110-114). |