DYNAMIC STABILITY OF A MOVING COLUMN SUBJECT TO AXIAL ACCELERATION AND FORCE PERTURBATIONS

The equation of motion of a free-free moving column with a prescribed axial acceleration is formulated based on Hamilton's principle and the assumed mode method. The slender column is used as a simple model for a missile or a launched vehicle. The column is under the action of ae rodynamic forces which are modelled as axial external loads at the end s of the column. The effects of axial sinusoidal perturbations in resp ect of axial acceleration and the external loads are then examined usi ng Bolotin's method. The respective regions of instability are determi ned by converting the resulting equations of boundary frequencies to t he standard form of a generalized eigenvalue problem. Instability regi ons for various combinations of external loads and axial acceleration of the column are presented.