To improve the design of flapping-wing air vehicles and have a better understanding of their dynamics

a prototype of a bird-like air vehicle with foldable flapping wings was designed

and the dynamics of the prototype was carefully analyzed. First

the flapping mechanism based on crank link was designed

meanwhile the kinematic model of the mechanism was established

and the kinetic equations of the mechanism were deduced via Lagrangian method. Then the estimation model of the aerodynamic forces on the flapping wings was set up using strip theory

and the aerodynamic parameters of both the straight and the foldable flapping wings

under the time symmetric and time asymmetric flapping patterns

were calculated. The results showed that higher lift forces could be obtained when the foldable wings underwent asymmetrical flapping

which was attributed to lower resisted forces during the up-stroke periods of the foldable wings. Finally

with the commercial software package ADAMS

the dynamics forces at the critical linkage positions of the flapping mechanism were simulated

and the results provided a suggestion on strengthening the flapping mechanism.