Vibration and flutter of unstiffened and orthogonally stiffened circular cylindrical shells

The problem of vibration and flutter analysis of simply-supported unstiffened and orthogonally stiffened circular cylindrical shells which are typical of missile bodies has been developed and programmed for digital computer solution. An extensive review of the existing literature covering various aspects of the shell flutter problem is given with a critical appraisal of the assumptions made, results obtained, etc. A comprehensive chronological bibliography is also included. The analysis and the programme which have been developed are capable of handling shells of arbitrary geometrical, modal and flow parameters. In the case of stiffened shells, the stiffener effects may be treated as 'averaged' ('smeared') or 'discrete' and in each case the influence of eccentricity, in-plane and rotary inertias may be studied. The aerodynamic generalised forces may be calculated using the linear piston theory, the linear piston theory with a correction for curvature, and the exact potential flow solution. By combining the invacuo-natural vibration analysis and the aerodynamic generalised forces the cylindrical shell flutter problem may be solved and the flutter boundaries may be obtained in each of the above cases. The procedures have been illustrated with typical examples in each of the above cases and the results discussed. A few shells have been tested using an experimental vibration rig designed and built for the purpose and compared with the theoretically predicted invacuo-natural frequencies and mode shapes.