The kinetic stability of a tangentially loaded strut

An experimental method for applying a tangential force to the end of a column is described. The force is obtained by jet reaction from a nozzle clamped to the end of the column and free to move between parallel plane air bearings in the plane of least column stiffness. Values of tangential load which cause instability have been determined for a range of columns, column lengths and nozzles, and the unstable motion of the system is described. A theoretical treatment is presented and close agreement is obtained between predicted and observed values of critical load and frequency of oscillation.