Galloping Movement of a Timoshenko-Bar, a Stability Analysis by Means of Time- and Space-Harmonic Balance.

Under certain conditions, elastic resistance bodies may become aerodynamically unstable and may gallop perpendicular to the flow. The equation of motion describing this phenomenon can be reduced to a structure typical for self-exciting oscillators. They consist of the feedback of a linear system described by a Green's function and a nonlinear operator. As far as the Green's function performs as a general low-pass filter, the calculation of spatially distributed periodic states may be based on time- and space-harmonic balance. This method is applied in two ways to investigate the stability behavior of a Timoshenko-bar perpendicular to the flow, the strong nonlinearity of which is caused aerodynamically.