Modeling And Analyse Of Flexible Flapping-Wing For A Micro Air Vehicle Based On Rigid Finite Element Method

For its extensive applications in military and civilian, bionic flapping wing micro air vehicle (FMAV) has captured special attention of many researchers in recent years. FMAVs offer many advantages such as that it can take off from the ground immediately, attain sufficient height, fly to desired destinations, maneuver in flight, hover and so on.When birds or insects are flying, there are large deformations on their wings under the action of aerodynamic force and/or by flapping motion. In order to imitate the flying of birds and insects better, the flapping wings should have considerable flexibility, thus flexible materials are used in the fabrications.The existed methods to model and analyze a flexible body need both some commercial packages and sophisticated skills as well. So to find an efficient method for analysis of flexible flapping-wing is necessary. In this thesis, a method, named the rigid element method, is employed. Comparing with the results gotten from ANSYS, it is confirmed that the rigid finite element method including its modify version are simple but efficient method for the present purpose.Results coming from rigid element method show that the higher the frequency of flapping the smaller amplitude of the wing deformation. And the variations of input torque have weakly impact on the deformation of the flexible wing. The deformations near the trailing edge are larger than that in leading edge.The stability of the motion of flexible flapping-wing becomes an important issue with the increasing of the flapping frequency. By calculating the largest lyapunov exponent and protracting both the phase portrait and the Poincare maps of the system, chaos can be found. And with the increasing of the flapping frequency, the chaotic motion will become apparently.