| Abstract: | 隨著輕型航空器的蓬勃發展，適墜性的設計考量也隨著越來越重要。航空載具的機身結構、地板結構以及座椅的設計為主要的適墜性作用範圍，在發生撞擊時機身結構可以防止撞擊時產生大範圍的變形避免生存空間受到壓迫。近年來複合材料在航空器上的應用比例逐年增加，所以複合材料飛機的結構安全性是重要的研究方向。
本研究應用有限元素法Abaqus分析單一纖維方向碳纖維複合材料和多層碳纖維複合材料之結構進行適墜性模擬並比較單一纖維方向碳纖維複合材料和多層碳纖維複合材料對於吸收能量的差異。本研究以Zenith公司的STOL CH 701輕型運動航空載具(Light Sport Aircraft, LSA)做為研究的標的物，以Pro/Engineer建立機身，機身材料使用單一纖維方向碳纖維複合材料、多層碳纖維複合材料，依據AGATE訂定的30o撞擊角度與ASTM規範的1.3 Vso下降速度作為本研究參數設定的邊界條件，動態模擬以撞擊能量的輸出做為結果合理性判斷的依據，再利用Abaqus軟體分別討論兩者在相同負載條件下的能量吸收能力以及座艙壓縮率。
本研究根據MIL-STD-1290A所規定的座艙壓縮率在各方向的壓縮率不得超過15%的安全標準下，建立速度與角度的關係圖。在不同的撞擊角度與不同的撞擊速度下，0o纖維還是佔有關鍵性的影響力，擁有0o纖維的機身模型，都有較高的內能吸收。不同纖維排列方式的機身在沿著Y方向的壓縮率都相較於X方向與A斜樑方向為小，其最大壓縮率都不超過3%。撞擊速度對於座艙壓縮率的影響比撞擊角度的效應為明顯。不同纖維排列方式的機身座艙之X方向與A斜樑方向，在不同撞擊速度的壓縮率都相對高於在固定速度不同角度撞擊時之變形量。
Because of the development of light sport aircraft, the design of the crashworthiness becomes more and more important. Light sport aircraft’s fuselages structure, floor structure and seats are designated for crashworthiness. It can prevent large deformation to maintain the survival of space during the impact. In the recent years, the proportion of composite materials in the aircraft increased year by year, so the safety of the com-posite aircraft is the important field to research.The purpose of this thesis is using finite element method, Abaqus, to simulate the crashworthiness of Single-layer and Multi-layer composite materials and comparison of impact energy absorption capability be-tween Single-layer and Multi-layer composite materials. In this thesis, we use Zenith’s STOL CH 701, Light Sport Aircraft, as model to simulate. This research used Pro/Engineer to establish CH 701 fuselage model. The material of fuselage are Single-layer and Multi-layer composite materials. According to the AGATE and ASTM, the impact angle and the impact velocity are 30o and 1.3VSO using as boundary condition of dynamic simulation. In the dynamic simulation, we output the data to check if the simulation is follow the conservation of energy and use Abaqus to discuss the impact energy absorption capability and reducing rate of cabin between Single-layer and Mul-ti-layer composite materials.
In this thesis, the relationship between velocity and angle was established according to the safety standard, MIL-STD-1290A, of the cockpit reducing rate cannot more than 15%. In different impact angles and different impact velocities, 0o composite fiber has a critical influence.0o composite fiber fuselage model has a higher energy absorption in all Single-layer and Multi-layer fuselage. In both Single-layer and Multi-layer composite fuselages, the compression of the cabin in the Y direction is smaller than the X direction and the A direction, and the maximum reducing rate does not exceed 3%. The effect of the impact velocity is more obvious than the impact angle on the cabin compression. The compression of fuselage in the X direction and A direction at different impact velocities are relatively higher than the deformation at different angles. |
