Vibration of laminated composite skew hypar shells using higher order theory

Free vibration analysis of laminated composite skew hypar shells are presented using a C0 finite element (FE) formulation based on higher order shear deformation theory (HSDT). Effect of cross curvature is included in the formulation. The C0 finite element formulation has been done quite efficiently to overcome the problem of C1 continuity associated with the HSDT. The isoparametric FE used in the present model consists of nine nodes with seven nodal unknowns per node. Since there are no results available in the literature based on HSDT on the problem of free vibration of laminated composite skew hypar shells, present results are validated with the results available for laminated composite hypar shells without skew angle and with the results available for laminated composite skew plates. New results are presented by varying geometry, boundary conditions, ply orientations and skew angles.

► A comparative study of the results shows that the present formulation gives better results.
► There is no result for composite skew hypar shells, therefore, present results will serve as benchmark.
► Amplitudes of mode shapes for fundamental mode decrease as the skew angle increases.
► With increased skew angle, fundamental frequency increases except for CFCF shell.