抄録
In order to clarify the flight mechanism of butterfly, we have observed the butterfly flight using high-speed camera. The Test butterfly is Cynthia cardui and its diameter is 25mm in wing chord length, 30mm in wing span length, 254mm2 in wing area and 160mg in weight. Especially, we have discussed the dynamic behavior of butterfly wing in flight motion, such as the elastic deformation of wing, the trajectory of wing tip and the flapping angle of wing. In flight motion of butterfly, the wing carried out elastic deformation not only in the wing span direction but also in the wing chord direction. The flapping angle shows the periodic triangular waveform and the ratio of between the up stroke and down stroke of flapping motion is about 1:1.25.
