多層複合材料之輕航機起落架能量吸收評估

Evaluation of Light Aircraft Laminated Composites Landing Gear’s Energy Absorption

邱沛安(Pei-An Chiu)

指導教授 ： 陳步偉

淡江大學/工學院/航空太空工程學系碩士班/碩士(2020年)

https://doi.org/10.6846/TKU.2020.00848

摘要

近幾年製作以複合材料結構為主之飛行器為航太產業的趨勢，複合材料因其強度高、重量輕的特性使用率節節攀升，但在飛機結構中主要支撐整架飛機及乘載衝擊能的起落架仍然是採用金屬材料，小型飛機亦是如此。因此本研究將探討單層與多層複合材料之輕航機起落架以及既有之鋁合金起落架，在不同垂直衝擊速度下所承受之最大應力和能量吸收的差異性。

　　本研究使用STOL CH701主起落架為分析樣本，材料選用鋁合金6061-T6與碳纖維複合材料T300/LTM45-EL。利用Creo繪圖軟體建立起落架模型，並匯入Abaqus/Explicit有限元素分析軟體，負載條件以AGATE所訂定之垂直速度(18 m/s)為標準進行墜撞模擬，並輸出應力及能量做為判斷結構是否破壞及驗證模擬結果的合理性。

　　本研究中鋁合金與碳纖維複合材料起落架的重量分別為8.56 kg與5.07 kg，碳纖維複合材料相對鋁合金重量減輕約40.77%，減少了重量成本並可降低運行時的油耗。在比較不同材料之內能吸收量時，鋁合金起落架的能量吸收效果最高，45˚纖維及多層中[45/-45]纖維組合的能量吸收最低且低於約39.86%~40.3%。鋁合金起落架在衝擊速度超過6 m/s時，其結構已超過可承受之最大應力即受到材料破壞產生失效，但碳纖維複合材料起落架在衝擊速度來到38 m/s時，只造成多層複材中[0/45/90]及[0/45/-45/90]兩種組合的破壞。比較SEA效率時當衝擊速度低於6 m/s，多層中的[0/90]纖維組合有最高的SEA值，但0˚纖維只低於約1%，當衝擊速度高於6 m/s時，0˚纖維的吸能效果是最好的，顯示出多層複合材料並沒有較佳的吸能效果。複合材料中單層45˚纖維及多層中[45/-45]纖維組合在每種衝擊速度下能量吸收值皆是最低的，而若不同纖維角度組合中含有0˚纖維，則吸能能力較佳。

關鍵字

多層複合材料 ； 輕航機起落架 ； 能量吸收

並列摘要

In recent year, because of the light weight and high strength of composite materials, the utilization rate in the aerospace industry is increasing. But the landing gear that mainly supports the entire aircraft and absorbs impact energy is still made of metal, as is the small aircraft. Therefore, this study will explore the difference between the maximum stress and energy absorption of single-layer and multi-layer composite and aluminum alloy light aircraft landing gears under different vertical impact speeds.

　　In this study uses STOL CH 701 main landing gear as the analysis model. The material is aluminum alloy 6061-T6 and carbon fiber composite material T300/LTM45-EL. We use Creo (Pro-Engineering) create the landing gear model and import into Abaqus/Explicit finite element analysis software, according to the vertical velocity (18 m/s) in AGATE as the standard of the simulation. Finally, we check whether the structure is damage and verify the result of simulation by output the stress and energy.

　　The result of this study, the weight of the landing gear of aluminum alloy and carbon fiber composite materials is 8.56 kg and 5.07 kg, respectively, the weight of carbon fiber composite material is reduce about 40.77% than aluminum alloy. Reduce the cost of weight can also reduce fuel consumption. The energy absorption of aluminum alloy landing gear is the highest, 45˚ fiber and multi-layer [45/-45] is the lowest and less than aluminum alloy about 39.86%~40.3%. When the impact speed exceeds 6 m/s the aluminum alloy landing gear is damage and when the impact speed reach 38 m/s only multi-layer [0/45/90] and [0/45/-45/90] are damage. The SEA of multi-layer [0/90] is highest when impact velocity is lower than 6 m/s, but 0° fiber is only less then multi-layer [0/90] about 1%. When impact velocity is higher than 6 m/s the SEA of 0° fiber is the highest. It shows that the energy absorption effect of the multi-layer composite material is poor. In the composites material, the energy absorption of the 45˚ fiber and multi-layer [45/-45] are the worst in all impact speed, and if the multi-layer contains 0˚fiber the energy absorption is better.

並列關鍵字

Laminated Composites ； Light Aircraft Landing Gear ； Energy Absorption

參考文獻

參考文獻

[1] Faye Smith, “The Use of composites in aerospace: Past, present and future challenges”, Avalon Consultancy Services Ltd, 2013.

[2] Adam Quilter, “Composites in Aerospace Applications”, IHS ESDU, 2001.

[3] Shivi Kesarwani, “Polymer Composites in Aviation Sector”, Internationl Journal of Engineering Research & Technology, ISSN: 2278-0181, Vol. 6, Issue 6, June 2017.

[4] “Status of FAA’s Actions to Oversee the Safety of Composite Airplanes”, United States Government Accountability Office, September 2011, pp. 5-6.