本研究欲設計出一無人飛機起落架系統，用於機身重量至少八公斤之無人載具，且具有可收放性之功能，並搭配CAE軟體，以有限元素分析法進行模擬，模擬包含網格收斂分析、靜態模擬與動態模擬。在設計適合的起落架前，先針對現有的起落架應用做較全面性的資料收集與分析，進而從中建立一套起落架的資料庫系統，幫助我們了解不同的飛機設計該選用何種起落架較為恰當。設計之初，考量起落架收放時各個連桿間的作動，以市售致動器作為動力來源，拉動連桿，帶動起落架之收放，針對落地時所受的衝擊設計下鎖機構，確保起落架能承受撞擊，使無人載具穩定降落，此外，對設計完成的起落架進行電腦模擬分析的評估，透過網格收斂性分析選定有效的有限元素模型，靜態模擬與動態模擬是施加邊界條件與負載於模型上，測試結構之牢固性，而動態模擬又包含收放分析、落錘模擬、觸地撞擊模擬，以驗證所選的起落架設計方式符合目前需求。完成模擬後將設計的起落架實際製作出來，驗證其收放功能與落地的抗衝擊能力，並與模擬結果互相比對，最後落錘試驗結果與模擬結果極為相似，且具有承受落地衝擊之結構強度。

The aim of this research is to design a retractable landing gear of the unmanned aerial vehicle, which can load at least eight kilograms. The author uses CAE software based on the finite element method (FEM) to simulate the static/dynamic responses of a landing gear model built for the use of a small unmanned airplane. First, some references UAVs in use nowadays were surveyed for their types of main landing gears, from which a small database was developed. From the database, it can thus be determined to have a suitable type for the present case. The main landing gear was designed by a linkage system equipped with an actuator, where no constructive interference was present in the retracting motion. To prevent a break of phase-lock when landing, a down-lock mechanism was designed. As the last phase, the static/dynamic behaviors of the main landing gear, including the dropping test and a stress analysis, were simulated using FEM to ensure its safety of landing. From the FEM analysis, the model can be easily modified to meet different criteria. At last, the designed model was manufactured and tested for verifying the previous FEM analysis. Eventually, the test results showed consistency in quality when compared with the FEM simulations.

[1] 陸偉銘，“F-5E起落架減震系統動態分析”，國立成功大學航空太空工程學系碩士論文，1986。
[2] 陳萬年，“無人飛行載具起落架動態負載分析之研究”，國立成功大學機械工程學系碩士論文，2000。
[3] Mohammed Imrana, Shabbir Ahmed. R. Mb, Mohamed Haneefc, “FE Analysis for Landing Gear of Test Air Craft,” 4th International Conference on Materials Processing and Characterization, 2015.
[4] Thoai D. Nguyen, “Finite Element Analysis of a Nose Gear During Landing,” UNF Theses and Dissertations, 2010.
[5] 王木百村，“電腦輔助工程分析簡介與應用”，國立屏東科技大學機械工程系暨研究所講義。
[6] 羅佐良，“結構設計與分析”，智慧化工具機技術中心講義，2014。
[7] 王強，世界軍用無人飛機圖鑑，四塊玉文創出版社，2015。
[8] Unmanned aerial vehicle, https://en.wikipedia.org/wiki/Unmanned _aerial_vehicle
[9] Cessna - Textron Aviation, http://cessna.txtav.com/
[10] Daniel P. Raymer, Aircraft Design: A Conceptual Approach, American Institute of Aeronautics and Astronautics Inc., 1992.
[11] FAA Federal Aviation Regulations, Part 23 -Airworthiness standards: Normal, utility, acrobatic, and commuter category airplanes.
[12] ASTM International, Designation: B308/B308M–10, Standard Specification for Aluminum-Alloy 6061-T6 Standard Structural Profiles1, 2016.
[13] ASTM International, Designation: B247-02a, Standard Specification for Aluminum and Aluminum-Alloy Die Forgings, Hand Forgings, and Rolled Ring Forgings, 2009.
[14] ASTM International, Designation: Designation: D638–14, Standard Test Method for Tensile Properties of Plastics1.
[15] AZO Material, http://www.azom.com/properties.aspx?ArticleID =516
[16] Benjamin Milwitzky and Francis E. Cook, Analysis of Landing-Gear Behavior, Langley Aeronautical Laboratory Report 1154, 1953.