Construction and Analysis of a Lightweight UAV Wing Prototype Aerospace Engineering

120 Pages·2015·10.53 MB·English

by  Andre C. Marta

Construction and Analysis of a Lightweight UAV Wing
Prototype
Mário Hernâni Silva Ramos
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisor: Prof. André Calado Marta
Examination Committee
Chairperson: Prof. Filipe Szolnoky Ramos Pinto Cunha
Supervisor: Prof. André Calado Marta
Member of the Committee: Prof. Virginia Isabel Monteiro Nabais Infante
November 2015
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Tomyparents,fortheirunconditionalsupportthrougheverystepofmylife.
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Acknowledgments
I would like to thank my thesis supervisor, professor Andre´ Calado Marta, for all the guidance and
support.
I would also like to thank professors Virginia Infante and Zuzana Dimitrovova´ for giving me the op-
portunity to observe some test using the VIC software and letting me now as much as possible about
it.
To professor Lu´ıs Reis, I would like the thank for all the help with the testing of the balsa and com-
positespecimens.
Lastbutnotleast,Iwouldliketosincerelythankmyfamilyandfriends. Theirpresenceandsupport
throughout the good and the bad moments of my academic career was essential in helping me reach
thispoint.
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Resumo
O aumento na utilizac¸a˜o de aeronaves na˜o tripuladas nos u´ltimos anos conduziu a um mercado mais
competitivo, onde mais atenc¸a˜o tem vindo a ser dada a` eficieˆncia e seguranc¸a com as quais estas
aeronaves completam os objectivos das suas misso˜es. Tendo isso em conta, um maior foco tem sido
colocadosobreafasepreliminardoseudesignestrutural,ondeasrecentesevoluc¸o˜esan´ıveldaana´lise
computacionalusandoome´tododoselementosfinitospossibilitamumamelhorprevisa˜odocomporta-
mento da estrutura final. Nesta tese, um proto´tipo de uma nova estrutura para a asa de um UAV de
asa fixa e´ constru´ıdo, e os resultados obtidos pelos testes nele feitos comparados com os do modelo
nume´rico constru´ıdo no CATIA(cid:13)R. Com vista a tal, um modelo CAD tanto da estrutura da asa como do
proto´tipo foi concebido, com base em paraˆmetros de design identificados. Os materiais seleccionados
para o proto´tipo sa˜o testados, as suas propriedades ela´sticas determinadas e uma validac¸a˜o desses
testes efectuada no mo´dulo de ana´lise estrutural do CATIA(cid:13)R. O processo de produc¸a˜o do proto´tipo e´
descrito, sendo feitas considerac¸o˜es relativamente a` influeˆncia de cada pec¸a e material no peso final
da estrutura. Os testes feitos no proto´tipo sa˜o apresentados, e uma comparac¸a˜o feita entre os seus
resultadoseosdaana´liseporelementosfinitos, seguidadeumadiscussa˜odasdiferenc¸asentreeles.
Concluso˜es sobre a precisa˜o do modelo nume´rico obtido sa˜o feitas, e sugesto˜es para minimizar as
discrepaˆnciasidentificadasrecorrendoaumprocessodeproduc¸a˜omaiscontroladosa˜oapresentadas.
Este trabalho tem como objectivo estabelecer uma base para futuras geometrias computacionais de
UAVS,usandoasferramentasdeana´liseporelementosfinitosaquiafinadas.
Palavras-chave:
Me´tododeelementosfinitos,Propriedadesdosmateriais,Testedemateri-
ais,Validac¸a˜o,Proto´tipo,Ana´liseestrutural.
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Abstract
An increase in the usage of Unmanned Aerial Vehicles (UAV) in the last couple of years has led to a
more competitive market where more attention is being given to the efficiency and safety with which
thoseaircraftaccomplishtheirmissiongoals. Bearingthatinmind,agreaterfocusisputontheirprelim-
inarystructuraldesign,wherethedevelopmentofcomputationalFiniteElementAnalysis(FEA)methods
allow for a better prediction of the behavior of the final structure. In this thesis, a prototype based on
a new, suggested wing structure for a particular fixed wing UAV is built, and the results obtained by
the experimental tests carried out on it compared to those yielded by a numerical model developed in
CATIA(cid:13)R. To do so, a CAD model of both the suggested wing structure and its prototype is created,
basedonidentifieddesignparameters. Thematerialsselectedfortheprototypearetested,theirelastic
properties determined and a validation of those tests made in CATIA(cid:13)R’s Generative Structural Analy-
sis workbench. The building process of the prototype is described, and considerations regarding the
influence of each material and part in its final weight are made. The tests performed on the prototype
are presented, and a comparison between their results and those of the FEA is made, followed by a
discussion of the differences between them. Conclusions on the accuracy of the numerical model are
drawn, and suggestions of ways to minimize those discrepancies by means of a more controlled build-
ing process are presented. This effort is aimed to pave the way for future higher-fidelity computational
structuraldesignsofUAVsusingthetunedFEAtools.
Keywords:
Finiteelementmethod,Materialproperties,Materialstesting,Validation,Prototype,
Structuralanalysis.
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