Multi-mode air damping analysis of composite cantilever beams

A theoretical and experimental study on multi-mode air damping of SiO2-Au composite cantilever beams is presented. Calculation of the resonant frequencies is effected by taking into account the effect of the coated gold layer. Theoretical values agree well with the experimental results up to the third mode. Quality factors are computed using two different models, the first one is based on the equivalent sphere model and the second one uses hydrodynamic functions. For both models, the theoretical results show a very good agreement with experimental ones for the first two modes.