Coupling theoretical data and translational FRFs to perform distributed structural modification

Predicting the effect of distributed structural modifications, such as rib or plate stiffeners, on structures for which a theoretical model is not ava ilable, is not practically considered in the technical literature: this is due to the objective difficulty of coupling continuous modifications with a n original structure known through its frequency response function. While t his is not the case when lumped modifications are accounted for, the possib ility of describing distributed modifications requires non-trivial operatio ns involving the use of different models for the structure and the modifica tion, an appropriate use of a condensation procedure and a careful consider ation of non-local effects introduced by the above condensation. The basic requirements for a. consistent modelling are here considered and some resul ts are presented. (C) 2001 Academic Press.