NATURAL VIBRATIONS OF LAMINATED COMPOSITE BEAMS BY USING MIXED FINITE ELEMENT MODELLING

A six-node, plane-stress mixed finite element model has been developed by using Hamiltonʹs energy principle for the natural vibrations of laminated composite beams. Continuity of the transverse stress and displacement fields has been enforced through the thickness of the laminated beam in the formulation for proper modelling. The transverse stress components have been invoked as the nodal degrees of freedom by applying elasticity relations. Natural frequencies of laminated composite beams obtained through the present formulation have been shown to be in good agreement with the data available in the literature. Various mode shapes have also been presented as benchmark solutions.