Delamination Effect on Composite Plates with Curvilinear Fibers: A Numerical Investigation of Eigenfrequencies

The effect of embedded delamination on the free vibration behavior of variable stiffness composite laminates (VSCL) has been investigated in this paper. The FSDT is applied to formulate the FE model of the plate using eight-noded isoparametric elements. Hamilton’s principle is used to obtain the governing equation. A region-wise model is implemented to mathematically express the centrally located square delamination. Both symmetric and unsymmetric laminates under various boundary conditions have been considered to examine the consequences of different delamination parameters (size and position) on the eigenfrequencies. Natural frequencies of the plate get reduced in presence of delamination due to the degradation of structural stiffness.