VIBRATION OF CANTILEVERED LAMINATED COMPOSITE SHALLOW CONICAL SHELLS

This paper presents a new mathematical model to investigate the free v ibration of laminated composite shallow conical shells in an effort to wards accurate modelling of turbomachinery blades. The shells are comp osed of symmetrically or unsymmetrically laminated composites. This st udy focuses on E-glass/epoxy conical shells with four and eight-ply la minates, but the analysis can be easily extended to any composites wit h an arbitrary number of plies and fibre orientation. The energy integ ral expression is derived on the basis of the shallow shell theory inc orporating variable chordwise surface curvature. A global computationa l approach based on the extremum energy principle is employed to deriv e the eigenvalue equation. A flexible, admissible global shape functio n is developed to account for the geometric boundary conditions. Previ ously unavailable frequency parameters and vibration mode shapes are p resented. (C) 1998 Elsevier Science Ltd.