DYNAMICALLY MODIFIED LINEAR STRUCTURES - DETERMINISTIC AND STOCHASTICRESPONSE

In the dynamical analysis structural modifications often appear for ma ny reasons such as designer structural alterations, and discrepancies between predicted and measured properties of the structures. Furthermo re, sometimes evaluating the eigenproperties of several structural sys tems, as non-classically damped structures or structural systems compo sed by a primary and a light secondary substructure, requires the adop tion of the perturbation approach by considering the real structure as a modification of the original structure. In this paper an unconditio nally stable step-by-step procedure able to evaluate both deterministi c and stochastic responses of linear structural systems with dynamical modifications is presented. The proposed procedure overcomes the nume rical drawbacks connected with the evaluation of the complex eigenprop erties of the modified structure. The procedure is based on evaluating in approximate form the fundamental operator of the numerical procedu re, either by a closed form expression or by an always convergent Tayl or series, as a function of the transition matrix of the unmodified st ructure.