FINITE-ELEMENTS FOR VIBRATION ANALYSIS OF UNSYMMETRIC LAMINATED COMPOSITE PLATES

A 38-DOF (degrees-of-freedom), high precision triangular element if de veloped for vibration analysis of laminated composite panels with expl icitly defined stiffness and mass matrices. A new, reduced-order, 18-D OF, high-precision element is formulated through condensation of the 3 8-DOF element; the order reduction is done at the element level instea d of the conventional condensation at the postassembly global matrix l evel Natural frequencies and mode shapes obtained using these two elem ents are compared with those available in the literature. Results indi cate excellent performance of the condensed element. In view of the re latively lower DOF, the reduced element is believed to be attractive f or evaluating dynamic response and vibration control analysis of unsym metric laminates.