Development of the Two-Step Delamination Identification Method by Resonant and Anti-Resonant Frequency Changes

Identification of the location and size of delamination is important for structural health monitoring of composite laminated structures, since delamination degrades compression stiffness of the structures. In the present study, a two-step delamination identification method using resonant and anti-resonant frequency changes is proposed. It is well known that resonant frequencies are changed depending on the location and size of delamination. As for anti-resonant frequencies, they also change mainly depending on the location of delamination. Since the resonant and anti-resonant frequencies are specified easily in the frequency response function, the present method is low cost and applicable to any structures. The present method is applied to delamination identification of carbon/epoxy cantilever beams, and effectiveness of the present method is discussed.