Free vibration analysis of delaminated bimaterial beams

Non-dimensional parameters, namely, axial stiffness ratio and bending stiffness ratio, are introduced to study the vibration of bimaterial beams with a single delamination. The use of these parameters provide a better understanding on the influence of the axial stiffness and bending stiffness of the delaminated layers on the vibration of a delaminated beam. Both the ‘free mode’ and ‘constrained mode’ models in the study of the vibration of delaminated beams are used in the present analysis. A relative slenderness ratio specific for delamination vibration is further introduced, which is shown to dominate the vibration characteristics of the beam. For lower slenderness ratios, the influence of the delamination decreases and a global vibration mode dominates. For higher slenderness ratios, the influence of the delamination increases and a local vibration mode prevails.