Abstract: The experimental investigation on flutter characteristics of composite torsion-box is presented in this paper. Vibration test, wind tunnel flutter test and the corresponding calculation are conducted. The torsion-box is composed of frame and skin. Two models of the same frame are tested, one of them covered with composite skin, the other with aluminium alloy skin of the same thickness. The composite skin is a balanced, symmetric laminate of the material T300/648, and its thickness is 0.5mm with the ply stacking [ + 4510/- 4520/ + 4510].The frame is made of aluminium alloy with the identical beam height of 3mm. Experimental and calculated date indicate that for the model with composite skin, the flutter speed is 16.7% higher than that with aluminium alloy skin, and the weight of the torsion-box is 17.7% lower.

Key words: composite torsion-box, flutter speed, weight of the torsion-box