Vibration response of an elastically point-supported plate with attached masses

Experimentally determined natural frequencies and modes shapes are presented for an elastically point-supported isotropic plate with attached masses under impulsive loading. These results are compared to frequencies and to modes shapes determined from the Rayleigh–Ritz method and a finite element analysis using COMSOL. Accelerometers mounted at three locations on the plate, provide input for ME’Scope Modal Analysis Software to identify frequency peaks and modes shapes. Orthogonal polynomials, which meet free–free plate boundary conditions, are selected as the basis functions used in the Rayleigh–Ritz method. A Mindlin plate theory, adjusted for negligible transverse shear effects, is used in COMSOL. Frequencies and mode shapes for four plate configurations are presented, compared using each method, and indicate good agreement between the numerical, analytical and experimental results.