Elastic stability and vibration characteristics of a composite case

Influences of radial internal pressure on elastic stability (buckling characteristics) of a composite case were analyzed based on the Flügge shell theory, in addition, influences of its geometric parameters and material properties on its buckling characteristics were also discussed. Results showed that increasing the internal pressure can improve the anti-buckling ability of the case within the limits of its strength. Furthermore, the dynamic responses of the composite case under a radical harmonic force were studied by applying the mode superposition method. It was shown that under the radial harmonic excitation, the frequencies of the maximum radial displacements in the excitation force plane and in the non-excitation forced plane are different; more specifically, the maximum radial displacement in the excitation force plane appears at the 3rd modal frequency of the case, but that in the non-excitation force plane appears at the fundamental modal frequency of the case.