Free Vibration Analysis of Generally Layered Composite Beam with Various Lay-Up and Boundary Conditions

Abstract

A mathematical formulation of the first order shear deformation theory to analyze free vibration of layered composite beam is discussed. The finite element model is prepared for the modal analysis by using 281 shell element which is having 8 nodes with six degrees of freedom at each node. The effect of material anisotropy, Poisson effect, slenderness ratio, lay-up angle and boundary conditions on the free vibration of the layered composite beams are studied by taking suitable example from various literatures. The modal analysis results obtained are tabulated and compared with the previously published analytical and experimental results to demonstrate the efficacy and accuracy of the model. AS4/3501-6 graphite-epoxy, glass-polyester and hydrothermally curvature stable composite are considered for this study. The prime focus of the work is to study the effect of multiple parameters on the natural frequency of four layered composite beam by using FE model since parametric study using analytical model would be highly complex. Natural frequency of all the modes is observed to be highly sensitive to a smaller layup angle than a higher lay up for all the boundary conditions. Poison effect cannot be neglected as it affects all the modes prominently.