1、Advances in Aircraft Landing Gear Advances in Aircraft Landing Gear Schmidt R. Kyle Schmidt PT-169 ISBN: 978-0-7680-8218-0 Advances in Aircraft Landing Gear R. Kyle Schmidt SAE INTERNATIONAL The aircraft landing gear system is relatively unique on board an aircraftit is both structure and machine, s
2、upporting the aircraft on the ground, yet providing functions such as energy absorption during landing, retraction, steering, and braking. Advances in Aircraft Landing Gear, edited by R. Kyle Schmidt, is a collection of eleven hand-picked technical papers that focus on the signi cant advancements th
3、at have occurred in this eld concerning numeric modeling, electric actuation, and composite materials. Additionally, papers discussing self-powered landing gear and more electrical overall aircraft architectures have also been included. The content of Advances in Aircraft Landing Gear is divided int
4、o two sections: Analysis and Design Methods; and Electric Actuation, Control, and Taxi, making it easier for the reader to nd information quickly. For those looking for additional knowledge on aircraft landing gears, the SAE A-5 committee (the Aerospace Landing Gear Systems Committee), serves as a u
5、seful forum for discussion on landing gear issues and development. A current listing of documents produced and maintained by this committee appears in the appendix of Advances in Aircraft Landing Gear. R. Kyle Schmidt R. Kyle Schmidt has twenty years of aircraft landing gear engineering experience g
6、arnered in Canada, France, and England. He has extensive exposure to the design, development, and in-service support of large civil aircraft landing gears, having been chief engineer for the A300/A310 family, A320 family, A330/A340 family, and A350 landing gears produced by Messier-Bugatti-Dowty. Wi
7、th a degree in mechanical engineering from the University of Waterloo, Mr. Schmidt is a licensed professional engineer in the Province of Ontario. An accomplished inventor having been granted over twenty patents, Schmidt has also published a number of papers related to landing gear health monitoring
8、 and event detection. AEROSPACEAdvances in Aircraft Landing Gear P150878_PT-169.indb 1 8/13/15 3:48 PMOther SAE books of interest: Integrated Vehicle Health Management: Perspectives on an Emerging Field By Ian K. Jennions (Product Code: R-405) Aircraft Maintenance By Bruce Aubin (Product Code: T-115
9、) Care and Repair of Advanced Composites By Keith B. Armstrong, William Cole, and Graham Bevan (Product Code: R-336) For more information or to order a book, contact: SAE INTERNATIONAL 400 Commonwealth Drive Warrendale, PA 15096 Phone: +1.877.606.7323 (U.S. and Canada only) or +1.724.776.4970 (outsi
10、de U.S. and Canada) Fax: +1.724.776.0790 Email: CustomerServicesae.org Website: books.sae.org P150878_PT-169.indb 2 8/13/15 3:48 PMAdvances in Aircraft Landing Gear By R. Kyle Schmidt Warrendale, Pennsylvania, USA P150878_PT-169.indb 3 8/13/15 3:48 PM Copyright 2015 SAE International eISBN: 978-0-76
11、80-8246-3Copyright 2015 SAE International. All rights reserved. Printed in the United States of America No part of this publication may be reproduced, stored in a retrieval system, distributed, or transmitted, in any form or by any means without the prior written permission of SAE International. For
12、 permission and licensing requests, contact SAE Permissions, 400 Commonwealth Drive, Warrendale, PA 15096-0001 USA; e-mail: copyrightsae.org; phone: 724-772-4028; fax: 724-772- 9765. Library of Congress Catalog Number 2015947533 SAE Order Number PT-169 http:/dx.doi.org/10.4271/pt-169 Information con
13、tained in this work has been obtained by SAE International from sources believed to be reliable. However, neither SAE International nor its authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall be responsible for any er
14、rors, omissions, or damages arising out of use of this information. This work is published with the understanding that SAE International and its authors are supplying information, but are not attempting to render engineering or other professional services. If such services are required, the assistan
15、ce of an appropriate professional should be sought. ISBN-Print 978-0-7680-8218-0 ISBN-PDF 978-0-7680-8246-3 ISBN-epub 978-0-7680-8248-7 ISBN-prc 978-0-7680-8247-0 To purchase bulk quantities, please contact SAE Customer Service e-mail: CustomerServicesae.org phone: +1.877.606.7323 (inside USA and Ca
16、nada) +1.724.776.4970 (outside USA) fax: +1.724.776.0790 Visit the SAE Bookstore at books.sae.org 400 Commonwealth Drive Warrendale, PA 15096 E-mail: CustomerServicesae.org Phone: +1.877.606.7323 (inside USA and Canada)+1.724.776.4970 (outside USA) Fax: +1.724.776.0790 P150878_PT-169.indb 4 8/13/15
17、3:48 PMV Table of Contents Introduction . 1 Analysis and Design Methods 3 Landing Gear Design in the Conceptual Design Phase (1999-01-5523) 5 Sizing the Landing Gear in the Conceptual Design Phase (2000-01-5601) 15 An Automatic Procedure for the Landing Gear Conceptual Design of a Light Unmanned Air
18、craft (2013-01-2188) 23 An Investigation of Landing Gear Shimmy: Tire Models, Tire Test Methodologies, Analysis and Parameter Studies (1999-01-5527) 37 Aircraft Level Steering Runaway Failure Analysis (2009-01-3136) .65 Bird and Tyre Impact Analysis on Landing Gear (2013-01-9002) 71 Electric Actuati
19、on, Control, and Taxi . 81 Examination of Aircraft Electric Wheel Drive Taxiing Concept (2008-01-2860) .83 Optimal Control Allocation for Electric Aircraft Taxi Systems: A Preliminary Study (2014-01-2137) 91 DRESS: Distributed and Redundant Electro-mechanical Nose Wheel Steering System (2009-01-3110
20、) .101 More Electrical Actuation for ATA 32: Modular Power Electronics and Electric Actuation, Control, and Taxi. A selection of the most relevant papers published by SAE International on these matters in the past fifteen years is included. The papers have been chosen to provide significant interest
21、 to those engineers working in the landing gear field. For those looking for more information on aircraft landing gears, the SAE A-5 committee (the Aerospace Landing Gear Systems Committee), which meets twice a year, serves as a useful forum for discussion on landing gear issues and development. The
22、 committee members produce standards, information reports, and recommended practices for the landing gear community. A current listing of documents produced and maintained by the A-5 committee is included in the appendix. P150878_PT-169.indb 1 8/13/15 3:48 PMP150878_PT-169.indb 2 8/13/15 3:48 PMAnal
23、ysis and Design Methods P150878_PT-169.indb 3 8/13/15 3:48 PM11999-01-5523 Landing Gear Design in the Conceptual Design Phase Patrick Berry Linkping Univ. Copyright by SAE International and the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. ABSTRACT A well designed lan
24、ding gear and a proper integration is of utmost importance for the success of any aircraft design. This should never be neglected but often is, especially in the conceptual design stage. This paper reflects the authors own experience in landing gear design on the Saab Gripen aircraft as well as expe
25、rience gained on aircraft conceptual designs of later dates. The aim of the paper is to underline the importance of spending more time on landing gear design and integration in conceptual design. The paper reflects the importance of proper interaction between landing gear design and other discipline
26、s and above all underlines the fact that landing gear design should be treated as an equally important design parameter, just as any other, in the final choice of aircraft configuration. INTRODUCTION The close relationship between airframe structural design and landing gear design is important to re
27、cognise. The landing gear usually accounts for 3-5% of MTOW. Impact on the airframe could be a lot more, sometimes 10-25% depending on how you solve the problem. The potential for weight saving is thus great if only enough time is allocated to solving the problems related to landing gear integration
28、. Design of other types of systems nearly always follow the state of the art and are therefore difficult to predict in the long perspective. There are no such problems with the landing gear. The landing gear is always tailored to the needs of the specific aircraft. HOW CHOICE OF AIRCRAFT CONFIGURATI
29、ON AFFECTS LANDING GEAR DESIGN WING MOUNTED MAIN GEARS Depending on aircraft configuration, whether it is a high, low or a midwinged design, the conditions for the landing gear differs. A high or a midwinged aircraft generally favour fuselage mounting, but there are exceptions of course. High wing c
30、onfigurations In a high wing configuration the gear needs to be longer and thus sometimes turns out heavier than normal. This is more or less compensated for, by the simple and rather elegant way the gear is retracted into the nacelle. No disruption of the wingbox makes it in the overall picture a v
31、ery attractive solution. Low wing configurations The same kind of elegant solution as above can be accomplished also in an unswept low wing configuration with even better result, since the main gear can be made shorter and hence lighter (Figure 1). A swept low wing design usually incorporates a so-c
32、alled kick spar, or a yehudi, behind the rear spar to avoid the sidefolding main gear to disrupt the wingbox. In this case the wingroot is thickened as a direct cause of the greater chord needed, which allows more fuel to be housed. This automatically creates another advantage, that of incorporating
33、 deeper wingspars in the root section. Here wing bending is most critical and thus the possibility of building a lighter wing is enhanced. Although positive in every sense to the wing, there is a major disadvantage to the fuselage. Figure 1. Typical wing mounted main gear (IL 114) P150878_PT-169.ind
34、b 4 8/13/15 3:48 PM5 11999-01-5523 Landing Gear Design in the Conceptual Design Phase Patrick Berry Linkping Univ. Copyright by SAE International and the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. ABSTRACT A well designed landing gear and a proper integration is of
35、 utmost importance for the success of any aircraft design. This should never be neglected but often is, especially in the conceptual design stage. This paper reflects the authors own experience in landing gear design on the Saab Gripen aircraft as well as experience gained on aircraft conceptual des
36、igns of later dates. The aim of the paper is to underline the importance of spending more time on landing gear design and integration in conceptual design. The paper reflects the importance of proper interaction between landing gear design and other disciplines and above all underlines the fact that
37、 landing gear design should be treated as an equally important design parameter, just as any other, in the final choice of aircraft configuration. INTRODUCTION The close relationship between airframe structural design and landing gear design is important to recognise. The landing gear usually accoun
38、ts for 3-5% of MTOW. Impact on the airframe could be a lot more, sometimes 10-25% depending on how you solve the problem. The potential for weight saving is thus great if only enough time is allocated to solving the problems related to landing gear integration. Design of other types of systems nearl
39、y always follow the state of the art and are therefore difficult to predict in the long perspective. There are no such problems with the landing gear. The landing gear is always tailored to the needs of the specific aircraft. HOW CHOICE OF AIRCRAFT CONFIGURATION AFFECTS LANDING GEAR DESIGN WING MOUN
40、TED MAIN GEARS Depending on aircraft configuration, whether it is a high, low or a midwinged design, the conditions for the landing gear differs. A high or a midwinged aircraft generally favour fuselage mounting, but there are exceptions of course. High wing configurations In a high wing configurati
41、on the gear needs to be longer and thus sometimes turns out heavier than normal. This is more or less compensated for, by the simple and rather elegant way the gear is retracted into the nacelle. No disruption of the wingbox makes it in the overall picture a very attractive solution. Low wing config
42、urations The same kind of elegant solution as above can be accomplished also in an unswept low wing configuration with even better result, since the main gear can be made shorter and hence lighter (Figure 1). A swept low wing design usually incorporates a so-called kick spar, or a yehudi, behind the
43、 rear spar to avoid the sidefolding main gear to disrupt the wingbox. In this case the wingroot is thickened as a direct cause of the greater chord needed, which allows more fuel to be housed. This automatically creates another advantage, that of incorporating deeper wingspars in the root section. Here wing bending is most critical and thus the possibility of building a lighter wing is enhanced. Although positive in every sense to the wing, there is a major disadvantage to the fuselage. Figure 1. Typical wing mounted main gear (IL 114) P150878_PT-169.indb 5 8/13/15 3:48 PM
