What causes aerodynamic flutter?

This flutter is caused by the coalescence of two structural modes – pitch and plunge (or wing-bending) motion . This example wing has two basic degrees of freedom or natural modes of vibration: pitch and plunge (bending). The pitch mode is rotational and the bending mode is a vertical up and down motion at the wing tip.

Flutter is a self-excited vibration of the wing of an aircraft around which air is flowing . It is caused by an interplay of aerodynamics and elastic forces as well as by inertial forces. Flutter can result in damages to the structure, possibly even leading to a crash.

Different types of aeroelastic effects are commonly distinguished from each other. They include vortex-induced vibration, galloping, flutter, and aerodynamic damping . where m is the mass per unit length of the structure.

Aeroelastic flutter involves the unfavorable interaction of aerodynamic, elastic, and inertia forces on structures to produce an unstable oscillation that often results in struc- tural failure. High-speed aircraft are most susceptible to flutter although flutter has occurred at speeds of 55 mph on home-built aircraft.