Finite elements for vibration analysis of unsymmetric laminated composite plates

A 38-DOF (degrees-of-freedom), high precision triangular element if developed for vibration analysis of laminated composite panels with explicitly defined stiffness and mass matrices. A new, reduced-order, 18-DOF, high-precision element is formulated through condensation of the 38-DOF element; the order reduction is done at the element level instead of the conventional condensation at the postassembly global matrix level Natural frequencies and mode shapes obtained using these two elements are compared with those available in the literature. Results indicate excellent performance of the condensed element. In view of the relatively lower DOF, the reduced element is believed to be attractive for evaluating dynamic response and vibration control analysis of unsymmetric laminates.