Identification of stiffness, dissipation and input parameters of multi degree of freedom civil systems under unmeasured base excitations

A time domain dynamic identification technique based on a statistical moment approach has been formulated for civil systems under base random excitations in the linear state. This technique is based on the use of classically damped models characterized by a mass proportional damping. By applying the Itô stochastic calculus, special algebraic equations that depend on the statistical moments of the response can be obtained. These equations can be used for the dynamic identification of the mechanical parameters that define the structural model, in the case of unmeasured input as well, and the identification of the input itself. Furthermore, the above equations demonstrate the possibility of identifying the dissipation characteristics independently from the input characteristics. This paper discusses how the equations for solving the identification problem can be obtained and gives an application.