DYNAMIC INSTABILITY OF LAYERED ANISOTROPIC CIRCULAR CYLINDRICAL-SHELLS .2. NUMERICAL RESULTS

Numerical results for the parametric resonance response of layered anisotropic circular cylindrical shells are presented based on a theoretical development given in part I [1]. The principal regions of parametric resonance are determined numerically from the system of Mathieu equations derived in part I. Results are given for two particular graphite-epoxy shells. The effects of pre-instability inertia in the composite shell is shown to be similar to that discussed previously [2] in connection with isotropic shells. Specifically, it is found that inclusion of pre-instability inertia may result in increased widths of the instability regions of modes having instability forcing frequency very close to a natural frequency of the pre-instability motion of the shell. Also, the effect of pre-instability spatial variation on the principal regions of parametric resonance is separately studied. It is found that the widths of the instability regions may be greatly increased by inclusion of these spatial variations. © 1993 Academic Press Limited.