【正文】 ssembly Design 18 Generative Part Structural Analysis 19 Parameters and Formulas 20Chapter 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 33Chapter 5 Digital MockUp 38 Preparation for Digital MockUp 38 Frame Animation 41Chapter 6 Summary 43Reference 44III中國民航飛行學(xué)院航空工程學(xué)院畢業(yè)論文Chapter 1 ReviewsLanding 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 production efficiency. To lifting the plane landing gear parts production efficiency, the project has put forward fast of parameterized modeling and of parameterized modeling can also be used in other parts. CATIA (Computer Aided TriDimensional Interface Application) is the modeling software to build up a threedimensional model of the platform The meaning of this researchThe reliability of the landing gear plays an important role to the safety of the aircraft, the structure and appearance of the landing gear also decides the economy of the aircraft. And the reliability of the landing gear is by its original design program of the science and engineering analysis. So it is a great significance to research the modeling of the landing gear. This report start at civil aviation maintenance engineering professional characteristics, and bining with 3D technology through to the landing gear of the modeling and finite element analysis, simulation the stress of the landing gear in the real situation, estimated the failure, loading of the important parts such as hydraulic ponents. It plays a vital significance to fault prediction of aircraft structure. The history of CATIACATIA started as an inhouse development in 1977 by French aircraft manufacturer Avions Marcel Dassault, at that time customer of the CAD/CAM CAD software to develop Dassault39。然后介紹了下CATIA V5的特點、應(yīng)用、基本操作、各種工作界面、零部件設(shè)計、裝配設(shè)計、運(yùn)動仿真、及較高層次的應(yīng)用。然后將各個部件導(dǎo)入裝配設(shè)計工作臺，進(jìn)行組裝，添加結(jié)構(gòu)約束。s Kitten, built in 1917, had retractable gear (but could not actually fly). The Dayton Wright RB1(Figure 21) of 1920 and the Verville Sperry R3 of 1922 also had retractable gear. But these aircraft were rarities and most airplanes had fixed landing gear at the end of metal struts because they were easy to design, strong, and relatively lightweight.Figure 21 Aircraft RB1When designing an aircraft, engineers have always had to address five conflicting requirements. These are: performance, weight, cost, reliability, and maintenance. The best solution to the performance requirement was to pull the landing gear pletely inside the fuselage and cover them over, presenting a smooth surface that produced no drag. But while ideal from a performance standpoint, this approach affected all of the other requirements at weighed more, cost more, was less reliable, and required more maintenance. The wind tunnel data from the PRT caused aircraft designers to look immediately for ways of developing landing gear that provided better performance and hopefully did not have too many other costs associated with them.The Boeing Monomail, which first appeared in 1930, and the Lockheed Orion are generally considered pioneers in the development of retractable landing gear, proving that it was practical. But airplane designer Jack Northrop, who was very interested in streamlining aircraft to improve performance, produced the Northrop Alpha, Beta, and Gamma with fixed landing gear during the 1930s. These aircraft had streamlined coverings that extended down from the fuselage, with the wheels sticking out at the bottom. These were generally referred to as trouser gear. (Figure 22) The Lockheed Sirius, which was built for Charles Lindbergh, had streamlined coverings over the wheels themselves that were referred to as pantstype landing gear. Although trouser and pants gear produced more drag than fully retracted gear, they were still a substantial improvement over uncovered landing gear. More importantly, they were still lighter, cheaper, more reliable, and easier to maintain than the retractable gear. But during the 1930s, numerous designers embraced retractable gear hey were willing to accept the other drawbacks of retractable landing gear simply to achieve the better performance.Figure 22 Pantstype landing gearAirplane designers explored numerous ways to retract aircraft landing gear into the fuselage. In some aircraft they were pulled straight up, usually into cowlings behind the engines, sometimes with part of the wheels protruding outside the airplane. In other cases, particularly with smaller aircraft, the struts folded inward so that the wheels fit into the bottom of the fuselage horizontally, sometimes covered with a door to further reduce drag. Some of the drive mechanisms were electric, whereas others were hydraulic. The designers had to ensure that the gear deployed and locked in place. Landing gear that collapsed when a plane landed could cause the plane to tumble out of control and kill the pilot, or at least seriously damage the airplane. For early retractable landing gear not even the performance improvements were clearly achievable, since a retractable landing gear with its motors and associated machinery weighed more than a fixed gear, thereby requiring greater lift from the air