【正文】 history of the landing gear and all kinds of structure form and retraction system are summarized. And some accident cause by landing gear are listed. Then the basic knowledge of CATIA V5 as covered, from the application characteristics to its user interface and all kinds of workbench. Before 3D modeling, first of all, some official data to determine the type of landing gear is collected, and some basic data is also collected. Then Hubcap, Cylinder, Drag brace, Torque arm, Collar and tire are modeled by simplified. The data of each part of the concrete, connecting forms, and lootion are be corrected. Then from the sketch of the various parts of the parts are modeled. The next step is martialing each parts and DMU. At the last, all kinds of deficiency and stay for improvement are summarized, and the advantages of CATIA modeling are prospected. Key Words: Landing gear, CATIA, structural design, DMU 中國(guó)民航飛行學(xué)院航空工程學(xué)院畢業(yè)論文 III Content Chapter 1 Reviews ........................................................................................................................... 1 The meaning of this research .......................................................................................... 1 The history of CATIA ........................................................................................................ 1 Chapter2 Overview the landing gear ............................................................................................ 4 Definition of landing gear.............................................................................................. 4 Different types of gear ................................................................................................. 7 Tricycle gear ........................................................................................................ 7 Taildragger............................................................................................................ 8 Unusual types of gear .......................................................................................... 9 Landing gear and accidents ............................................................................... 12 Chapter 3 Introduction about CATIA .......................................................................................... 14 CATIA’s Interface .......................................................................................................... 14 Mechanical design workbenches .......................................................................... 15 The Specification Tree ...................................................................................... 15 The Sketcher Workbench ................................................................................................. 16 Part design .................................................................................................................... 18 Assembly Design ............................................................................................................. 18 Generative Part Structural Analysis .......................................................................... 19 Parameters and Formulas ............................................................................................... 20 Chapter 4 Modeling process of landing gear ............................................................................ 21 Basic structure modeling ............................................................................................. 21 Main supporting pole............................................................................................ 21 Airplane Wheel design ........................................................................................ 25 Upper Drag Brace ................................................................................................. 28 Lower Drag Brace ................................................................................................. 29 Lock assembly ...................................................................................................... 30 Hydraulic shafts ................................................................................................. 31 Centering Unit steering collar and torque ..................................................... 31 Assembly ......................................................................................................................... 33 Chapter 5 Digital MockUp.......................................................................................................... 38 Preparation for Digital MockUp ................................................................................. 38 Frame Animation ............................................................................................................. 41 Chapter 6 Summary........................................................................................................................ 43 Reference ......................................................................................................................................... 44 中國(guó)民航飛行學(xué)院航空工程學(xué)院畢業(yè)論文 1 Chapter 1 Reviews Landing gear is an important part of the plane. It’s the main ponent for the plane on ground parking, rollout, takeoff, and landing. It can load the weight of the plane and absorb impact energy. The plane landing gear major functions for aircraft in the stationary state under the gravity and the impact of the takeoff and landing, controlling the plane on the ground motion. There is a wide range of plane landing gear model, so these cause the landing gear design difficult, processing document plicated, and maintainability low maintenance rate. It cost a long time from modeling to processing cycle, these lead to the descending of the pr