Dynamic stiffness for piecewise non-uniform Timoshenko column by power series—part II: Follower force

Abstract

A follower force is an applied force whose direction changes according to the deformed shape during the course of deformation. The dynamic stiffness matrix of a non-uniform Timoshenko column under follower force is formed by the power-series method. The dynamic stiffness matrix is unsymmetrical due to the non-conservative nature of the follower force. The frequency-dependent mass matrix is still symmetrical and positive definite according to the extended Leung theorem. An arc length continuation method is introduced to find the influence of a concentrated follower force, distributed follower force, end mass and stiffness, slenderness, and taper ratio on the natural frequency and stability. It is found that the power-series method can handle a very wide class of dynamic stiffness problem.