Numerical-experimental identification of the elastic and damping properties in composite plates

A novel method is presented for estimating the elastic and dissipative parameters of composite plates and shells through a mixed numerical-experimental identification procedure based on the natural frequencies, modal damping factors and mode shapes of the specimen under investigation. The modal quantities are measured with an optimized contact-free experimental setup using a loudspeaker for exciting the structure and a scanning laser interferometer for measuring the dynamic response. The corresponding numerical predictions are obtained with an accurate shell element model derived from the higher-order shear deformation theory and including a structural damping mechanism. Adequate objective functions relying on the discrepancy between the experimental and numerical modal data are developed for the parameter estimation. The proposed procedure is next applied to three test cases and the results obtained show that all the elastic properties and the major damping parameters can be estimated with a high accuracy.