Free vibration of delaminated composite sandwich beams

Consider a sandwich plate with anisotropic composite laminated faces and an ideally orthotropic honeycomb core. In this paper, a one-dimensional model considering the transverse shear effect and rotary inertia for the free vibration analysis of a sandwich plate with an across-the-width delamination located at the interface between the upper face and core is developed. With this model, the natural frequencies and mode shapes of the delaminated composite sandwich beams can be obtained by solving the eigenvalues and eigenvectors of 12 simultaneous homogeneous algebraic equations. Because there are no such general solutions presented in the literature, verification is done by some special cases such as delaminated composite beams (without core) and perfect composite sandwich beams (without delamination). Based upon this general solution, the effects of faces, core, and delamination on free vibration behavior of composite sandwiches are studied thoroughly.