A gradient method for viscoelastic behaviour identification of damped sandwich structures

The damping properties estimation assumes a viscoelastic model calibrated from experiments and simulations. This Note presents a gradient method for viscoelastic behaviour identification of damped sandwich structures devoted to the passive control of mechanical vibration. The method combines experimental data, numerical simulations realized with a complex non-linear eigenvalue solver using the asymptotic numerical method, and optimal control for the identification of viscoelastic parameters. An automatic differentiation tool is used to get numerical derivatives exact up to the machine precision with minimal user effort. Results are presented for a sandwich beam with a frequency dependent viscoelastic core. (c) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.