Dynamic identification of classically damped uncertain structures

The detection of structural damping is a crucial point in structural identification. Classic techniques usually refer to deterministic systems, since the assumption of randomness in the mechanical quantities implies non-trivial analytical difficulties in the development of both the direct and the inverse problem. In some recent works, starting from the statistics of mode-shapes and (undamped) frequencies, a perturbative approach has been introduced by the authors for the estimation of mean and variance of uncertain mass and stiffness. Here dissipative structures are considered; in detail, the method is applied for the stochastic structural identification of classically damped linear dynamic systems, dependent on a random parameter, assumed to be Gaussian. A numerical validation of the technique is then presented and discussed.