Laminated composite stiffened shallow spherical panels with cutouts under free vibration – A finite element approach

In this paper, finite element method has been applied to analyze free vibration problems of laminated composite stiffened shallow spherical shell panels with cutouts employing the eight-noded curved quadratic isoparametric element for shell with a three noded beam element for stiffener formulation. Specific numerical problems of earlier investigators are solved and compared to validate the present formulation. Moreover, free vibration problem of stiffened shallow spherical shell panels with different size and position of the cutouts with respect to the shell centre for different edge constraints are examined to arrive at some conclusions useful to the designers. The results are presented in the form of figures and tables. The results are further analyzed to suggest guidelines to select optimum size and position of the cutout with respect to shell centre considering different practical constraints.