structural design and analysis of the mission adaptive wings of an unmanned aerial vehicle a ...

135 Pages·2010·4.18 MB·English

by  Levent Ünlüsoy

STRUCTURAL DESIGN AND ANALYSIS OF THE MISSION ADAPTIVE
WINGS OF AN UNMANNED AERIAL VEHICLE

A THESIS SUBMITTED TO
THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES
OF
MIDDLE EAST TECHNICAL UNIVERSITY

BY

LEVENT ÜNLÜSOY

IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR
THE DEGREE OF MASTER OF SCIENCE
IN
AEROSPACE ENGINEERING

FEBRUARY 2010
Approval of the thesis:
STRUCTURAL DESIGN AND ANALYSIS OF THE MISSION ADAPTIVE
WINGS OF AN UNMANNED AERIAL VEHICLE
submitted by LEVENT ÜNLÜSOY in partial fulfillment of the requirements for the
degree of Master of Science in Aerospace Engineering Department, Middle East
Technical University by,

Prof. Dr. Canan Özgen _____________________
Dean, Graduate School of Natural and Applied Sciences

Prof. Dr. Ozan Tekinalp _____________________
Head of Department, Aerospace Engineering

Prof. Dr. Yavuz Yaman _____________________
Supervisor, Aerospace Engineering Dept., METU

Examining Committee Members:

Prof. Dr. Serkan Özgen _____________________
Aerospace Engineering Dept., METU

Prof. Dr. Yavuz Yaman _____________________
Aerospace Engineering Dept., METU

Assist. Prof. Dr. Melin Şahin _____________________
Aerospace Engineering Dept., METU

Assist. Prof. Dr. Ender Ciğeroğlu _____________________
Mechanical Engineering Dept., METU

Özcan Ertem, M.Sc. _____________________
Executive Vise President, TAI

Date: 05.02.2010
I hereby declare that all the information in this document has been obtained
and presented in accordance with academic rules and ethical conduct. I also
declare that, as required by these rules and conduct, I have fully cited and
referenced all material and results that are not original to this work.
Name, Last Name:
Signature:

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ABSTRACT
STRUCTURAL DESIGN AND ANALYSIS OF THE MISSION ADAPTIVE
WINGS OF AN UNMANNED AERIAL VEHICLE
Ünlüsoy, Levent
M.Sc., Department of Aerospace Engineering
Supervisor : Prof. Dr. Yavuz Yaman
February 2010, 114 pages
In this study, the structural design and analysis of a wing having mission-
adaptive control surfaces were conducted. The wing structure was designed in order
to withstand a maximum aerodynamic loading of 5 g due to maneuver. The structural
model of the wing was developed by using MSC/PATRAN package program and
that structural model was analyzed by using MSC/NASTRAN package program. The
designed wing was then manufactured by Turkish Aerospace Industries Inc.
(TUSAŞ-TAI). The finite element analysis results were verified by conducting
ground vibration tests on the manufactured wing. The comparative results were used
to tune the finite element model and the results obtained showed that the modeling
was very successful.

Keywords: Aircraft Structural Design, Finite Element Analysis, Mission-Adaptive
Wing, Experimental Model Tuning
iv
ÖZ
İNSANSIZ BİR HAVA ARACININ GÖREVE UYUMLU KANATLARININ
YAPISAL TASARIM VE ANALİZİ
Ünlüsoy, Levent
Yüksek Lisans, Havacılık ve Uzay Mühendisliği Bölümü
Tez Yöneticisi : Prof. Dr. Yavuz Yaman
Şubat 2010, 114 sayfa
Bu çalışmada, göreve uyumlu kontrol yüzeylerine sahip bir kanadın yapısal
tasarımı ve analizi yapılmıştır. Kanat, uçağın 5 g değerinde azami aerodinamik
yükleme ile yaptığı manevralara dayanabilecek şekilde tasarlanmıştır. Kanadın
yapısal modeli MSC/PATRAN paket programı kullanılarak oluşturulmuş, bu yapısal
modelin analizleri MSC/NASTRAN paket programı kullanılarak yapılmıştır.
Akabinde, tasarlanan kanat Türk Havacılık ve Uzay Sanayii A.Ş. (TUSAŞ-TAI)
tarafında üretilmiştir. Sonlu elemanlar analizlerinden elde edilen sonuçlar, üretilen
kanadın yer titreşim testleri yapılarak doğrulanmıştır. Karşılaştırmalı sonuçlar kanat
modelinin uyumlamasında kullanılmış; alınan sonuçlar oluşturulan modelin son
derece başarılı olduğunu göstermiştir.

Anahtar Kelimeler: Hava Araçlarının Yapısal Tasarımı, Sonlu Eleman Analizi,
Göreve Uyumlu Kanat, Deneysel Model Uyumlaması
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to my precious family
and
beloved wife
for their love, care and support
and
to my friends
for their patience over years

vi
ACKNOWLEDGEMENTS
I would like to express my gratitude to my supervisor Prof. Dr. Yavuz Yaman
for his patient guidance, encouragements, insight and support in this study.
I must also express my appreciation to my superiors within the project,
Assist. Prof. Dr. Güçlü Seber, Assist. Prof. Dr. Melin Şahin and Prof. Dr. Serkan
Özgen for their guidance.
I would like to deeply thank my colleagues Erdoğan Tolga İnsuyu and Evren
Sakarya for their help throughout this thesis study.
I would also gratefully appreciate the support and assistance of all my
cherished friends but especially Mehmet Efruz Yalçın.
I would like to thank my parents for their guidance and insight and my sister
and wife for their care and support.
Finally, this work was partially supported by The Scientific and
Technological Research Council of Turkey, through the project
‘TUBITAK/107M103, Aeroservoelastic Analysis of the Effects of Camber and Twist
on Tactical Unmanned Aerial Vehicle Mission-Adaptive Wings’. The author
gratefully acknowledges the support given.
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TABLE OF CONTENTS
ABSTRACT................................................................................................................iv
ÖZ................................................................................................................................v
ACKNOWLEDGEMENTS.......................................................................................vii
TABLE OF CONTENTS..........................................................................................viii
LIST OF TABLES.....................................................................................................xii
LIST OF FIGURES..................................................................................................xiv
LIST OF SYMBOLS.................................................................................................xx
LIST OF ABBREVIATIONS...................................................................................xxi
CHAPTER
1. INTRODUCTION....................................................................................................1
1.1 Background to the Study....................................................................................1
1.2 Scope of the Study.............................................................................................1
1.3 Limitations of the Study.....................................................................................2
2. LITERATURE REVIEW........................................................................................3
2.1 Mission Adaptive Aerial Vehicles.....................................................................3
2.2 Structural Issues in Mission Adaptive Wing Concept.......................................6
3. DESIGN OF THE MISSION ADAPTIVE WING..................................................8
3.1 Introduction........................................................................................................8
3.2 Design of Main Structural Parts and Selection of Materials..............................9
3.2.1 Location of Spars........................................................................................9
3.2.2 Selection of Materials...............................................................................10
3.2.3 Rib Locations............................................................................................10
3.2.4 Member Thicknesses and Final Selection of Materials............................12
3.2.5 Discussion and Conclusion.......................................................................15
4. STRUCTURAL MODELLING OF THE MISSION ADAPTIVE WING...........16
4.1 Introduction......................................................................................................16
4.2 Selection of Element Types.............................................................................16
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4.3 Geometrical Modeling for Finite Element Method..........................................17
4.4 Material and Element Property Definition.......................................................20
4.5 Mesh Generation..............................................................................................21
4.6 Element Connections and the Details of the Finite Element Model................24
4.6.1 Connection between Skin and Wing Torque Box Inner Structure............24
4.6.2 Connection between Spars and Ribs.........................................................26
4.7 Finite Element Model Details..........................................................................28
4.8 Application of the Boundary Conditions.........................................................28
4.9 Discussions.......................................................................................................29
5. STRUCTURAL ANALYSIS OF THE MISSION ADAPTIVE WING...............30
5.1 Introduction......................................................................................................30
5.2 Dynamic Analyses of the Wing Torque Box and Results................................30
5.3 Static Analyses of the Wing Torque Box and Results.....................................33
5.3.1 Wing Torque Box under Its own Weight..................................................33
5.3.2 Wing Torque Box under Aerodynamic Loading......................................36
5.3.3 Wing Torque Box under the Loading due to the Maximum Load Factor
Maneuver...........................................................................................................45
5.4 Buckling Analysis of the Skin of the Wing Torque Box and Results..............49
5.5 Discussion........................................................................................................51
6. MANUFACTURE OF A MISSION ADAPTIVE WING.....................................52
6.1 Introduction......................................................................................................52
6.2 Manufacturing Process.....................................................................................52
6.2.1 The Spars...................................................................................................52
6.2.2 The Ribs....................................................................................................54
6.2.3 Composite Skin.........................................................................................55
6.2.4 Corner Connectors....................................................................................56
6.2.5 Fasteners....................................................................................................57
6.2.6 The Process and Assembly.......................................................................57

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6.3 Modifications...................................................................................................63
6.3.1 The Modifications in Material Properties.................................................63
6.3.2 Modifications on the Total Mass..............................................................68
6.4 Discussion........................................................................................................69
7. GROUND VIBRATION TESTS OF THE MISSION ADAPTIVE WING..........70
7.1 Introduction......................................................................................................70
7.2 Experimental Setup..........................................................................................70
7.3 The Experiments and the Results.....................................................................72
7.3.1 The Impact Hammer Excitation................................................................72
7.3.2 The White Noise Excitation......................................................................77
7.3.3 The Sine Sweep Excitation.......................................................................78
8. VERIFICATION AND TUNING OF THE STRUCTURAL MODEL OF THE
MISSION ADAPTIVE WING..................................................................................80
8.1 Introduction......................................................................................................80
8.2 The Comparison of the Results of the Experiments and the Finite Element
Analyses.................................................................................................................80
8.3 The Structural Tuning of Model 1...................................................................81
8.3.1 Modeling the Structures for the Servo Support........................................82
8.3.2 Modeling the Servo Motor Access Seals..................................................84
8.4 The Mass Tuning of Model 1...........................................................................86
8.5 The Result of Tuning of Model 1.....................................................................88
8.6 Characteristics of the Model 2.........................................................................92
8.7 The Structural Analyses of the Model 2 and the Results.................................93
8.7.1 The Static Analyses of the Model 2..........................................................93
8.7.1.1 The Static Analysis under Own Weight.............................................93
8.7.1.2 The Static Analysis of the Model 2 in Cruise....................................96
8.7.1.3 The Static Analysis of the Model 2 in 5g Pull-down Maneuver........98
8.7.2 The Buckling Analysis of Model 2.........................................................101
8.8 Discussion......................................................................................................102

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