Influence of Flight Control Laws on Structural Sizing of Commercial Aircraft

179 Pages·2021·8.103 MB·English

by  Rahmetalla Nazzeri

Influence of flight control laws on structural sizing
of commercial aircraft

TU Braunschweig – Niedersächsisches
Forschungszentrum für Luftfahrt
Berichte aus der Luft- und Raumfahrttechnik
Forschungsbericht 2021-19
Influence of flight control laws on
structural sizing of commercial
aircraft
Rahmetalla Nazzeri
TU Braunschweig
Institut für Flugzeugbau und Leichtbau
Diese Arbeit erscheint gleichzeitig als von der Fakultät für
Maschinenbau der Technischen Universität Carolo-Wilhelmina zu
Braunschweig zur Erlangung des akademischen Grades eines
Doktor-Ingenieurs genehmigte Dissertation.
Bibliografische Information der Deutschen Nationalbibliothek
Die Deutsche Nationalbibliothek verzeichnet diese Publikation in der
Deutschen Nationalbibliografie; detaillierte bibliographische Daten sind im Internet
über http://dnb.d-nb.de abrufbar.
1. Aufl. - Göttingen: Cuvillier, 2021
Zugl.: (TU) Braunschweig, Univ., Diss., 2021
Diese Arbeit erscheint gleichzeitig als von der Fakultät für Maschinenbau der
Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des
akademischen Grades eines Doktor-Ingenieurs genehmigte Dissertation.n.
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1. Auflage, 2021
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ISBN 978-3-7369-7516-3
eISBN 978-3-7369-6516-4
Influence of flight control laws on structural sizing of
commercial aircraft
VonderFakult¨atfu¨rMaschinenbauder
TechnischenUniversita¨tCarolo-WilhelminazuBraunschweig
zurErlangungderWu¨rdeeines
Doktor-Ingenieurs
(Dr.-Ing.)
genehmigte
Dissertation
von:
M.Eng. RahmetallaNazzeri
aus(Geburtsort): Hamburg
eingereichtam: 04.03.2021
mu¨ndlichePru¨fungam: 05.10.2021
Gutachter: Prof. Dr.-Ing. P.Horst
Prof. C.Armstrong,PhD
2021

Acknowledgement
ThedevelopmentsintheframeofthisPhDthesisaretheresultofacollaborationbetween
theInstituteofAircraftDesignandLightweightStructuresoftheTechnischeUniversita¨t
BraunschweigandtheFlightPhysicsdepartmentatAirbusinHamburg.
In this sense I am very thankful to Prof. Dr.-Ing. Peter Horst and Dr.-Ing. Matthias
Hauptwhosupportedmeduringthetimeofthiscollaborativeresearchprojectwiththeir
broadknowledgeandexperience.
Further I would like to thank Prof. Cecil Armstrong with whom I had several inspir-
ingmeetingsduringthetimeofthisPhDthesis.
In addition, I am very thankful to Frank Lange, who was a personal mentor with his
professional expertise in all matters of loads analysis, and Dr.-Ing. Michael Kordt, who
managedthefundingandworkingconditionswithhisvaluablemanagementskills.
FurtherIwouldliketothankDr.-Ing.StephanAddenforhiswisdomandexpertiseduring
thisPhDthesis.
I would like to express my special thanks to Christophe Sebastien who originated the
projectthatlaidthefoundationforthisPhD.
Finally I am very thankful to my family who supported me with patience during this
periodofmyworkingcareer.

Abstract
The increasing demand for new civil aircraft across established airlines in industrialized
countriesandemergingmarketspushesaircraftmanufacturerslikeAirbustodevelopin-
novativesolutionsthatleadinparticulartomassreductions,improvedlifttodragratios,
higher take-off weight, less fuel consumption and hence less carbon dioxide emissions.
Onewaytoachievethesekindsofimprovementsmoreeffectivelyandinlessdevelopment
time is the use of multidisciplinary analysis and optimization. Additionally incremental
innovation is a driving strategy which intends to incorporate specific solutions for dedi-
catedpurposesonexistingaircraftmodels. InthissensetheintentionofthisPhDthesis
istodevelopamultidisciplinaryframeworkinordertoquantifytheimpactofloadallevi-
ationfunctionparameterchangesonstructuralcomponentslikethewingandfuselagein
termsofresultingmasschanges. Forthispurposeexistingin-houseAirbustoolsandself-
developed algorithms are implemented into this framework as a whole. The developed
iterative process chain covers the loads calculation including an active load alleviation
system, a structural assessment of the wing and fuselage components and a dedicated
feedback loop in order to update mass and stiffness properties of the loads calculation
model. The structural property optimization of the wing is based on a fully stressed
design approach while for the weight penalty estimation of the fuselage section internal
loads exceedance values are used. Only vertical balanced manoeuvres and continuous
turbulence load conditions are taken into account for this specific use case. The study
showsthatsignificantmassreductionsareachievablewhileontheotherhandestimated
masspenaltiesareirrelevant.