Identification of stiffness and damping properties of thin isotropic vibrating plates using the virtual fields method: theory and simulations

The present paper proposes a novel procedure to derive both stiffness and damping parameters from forced vibrating isotropic plates. The key feature is that displacement and curvature fields can be measured at different times over the whole surface of the plate by a suitable optical technique. As a consequence, the virtual fields method (VFM) provides sets of equations relating the stiffness and damping parameters to these measured fields and to geometric and excitation (frequency, amplitude) parameters. First, the theory of the VFM is exposed and, then, validation is performed on simulated full-field displacement and curvature data. Calculations are performed in the case of isotropic plates with low and high damping, at resonance and out of resonance. It is shown that the procedure is valid and robust to noise, except on the damping parameters when the damping is low. Future work necessary to develop the method is described as a conclusion.