飛具在次音速狀態下飛行，若機翼使用高展弦比及前掠翼設計，會較一般飛具擁有更佳的氣動性能及操控性能，但是此設計之機翼常會產生結構發散現象，因此本文定義發散飛行速度越大其抵抗發散能力越強，進行最佳搜尋，尋求抵抗發散能力較強的設計。
本文所採用之複材機翼氣彈數學模式為Hwu and Tsai(2002)依複材夾心平板理論模式所推導建立，然後本文以類神經網路法模擬、替代其發散速度(或動壓)的演算，再進行最佳化的搜尋。
文中將對各因素進行探討，包括複材纖維方向、機翼展弦比及前掠角，以了解這些因素對機翼抵抗發散能力的影響，將有助於機翼設計時之參考。

In subsonic speed, the aircrafts with high aspect ratio wing and forward swept wing may have superior aerodynamic performance and agile control, but it exists divergence problem. We define the higher divergence speed as the better performance to against divergence, and then find the optimum design to avoid divergence problem.
In this study, we use the aeroelastic model (Hwu and Tsai, 2002) of composite wing established by employing the theory of composite sandwich plates. Then, neural network technique was used to simulate the calculation to get divergence speed (or divergence dynamic pressure). After simulating, we can perform the optimal searching by using the trained neural network to get the objective function values.
Several interesting parameters was discussed in the present work, including fiber orientation, aspect ratio and swept angle. Through this study, we can understand the relation between the above parameters and divergence speed, which would be useful in wing design.

參考文獻

Brayton, R. K., Director, S. W., Hachtel, G. D. and Vidigal, L.,“A New Algorithm for Statistical Circuit Design Based on Quasi-Newton Methods and Function Splitting,” IEEE Trans. Circuits and Systems, Vol. CAS-26, pp. 784-794, Sept. 1979.
Hwu, C. and Tsai, Z. S., “Aeroelastic Divergence of Stiffened Composite Multicell Wing Structures,” Journal of Aircraft, Vol.39, No.1, 2002.
Hwu, C. and Hu, J. S., “Buckling and Postbuckling of Delaminated Composite Sandwich Beams,” AIAA Journal, Vol.30, No.7, pp.1901-1909, 1992.
Hu, J. S. and Hwu, C., “Free Vibration of Delaminated Composite Sandwich Beams,” AIAA Journal, Vol.33, No.9, pp.1-8, 1995.
Lottati, I., “Flutter and Divergence Aeroelastic Characteristics for Composite Forward Swept Cantilevered Wing.” Journal of Aircraft, Vol.22, No.11, p1001-1007, 1985.
Moh, J. S. and Hwu, C., “Optimization for Buckling of Composite Sandwich Plates,” AIAA Journal, Vol.35, No.5, pp.863-868, 1997.
Taylor, J. M., Butler, R. and Harrison, C., “Optimisation of composite wind-tunnel wing models for frequence, flutter and divergence,” The Aeronautical Journal, Vol.103, No.1020, pp.105-111, 1999.
Vanderplaats, G. N. and Weisshaar, T. A., “Optimum Design of Composite Structures,” Journal for Nunerical Methods in Engineering, Vol.27, pp.437-448, 1989.
Weisshaar, T. A., “Divergence of Forward Swept Composite Wings,” Journal of Aircraft, Vol.17, No.6, pp.442-448, 1980.
Dowell, E. H., A Modern Course in Aeroelasticity, Kluwer Academic Pub. , Netherlands, pp1-51, 1978.
John J. B. and Michael L. S., Aerodynamics for Engineers, Third Edition, Prentice-Hall Pub., U.S.A.
羅華強，” 類神經網路-Matlab的應用”，清蔚科技，2001。
車華、耿海軍，” 前掠翼戰機與未來”，解放軍報2000年06月07日第11版
宛同，”翼尖渦流對飛行安全之影響”，中國航空太空學會會刊28卷第三期，1998
周政宏，”神經網路-理論與實務”，松岡，1995。
葉怡成，”類神經網路模式應用與實作”，儒林，1993。