Estimation of the Structural Dynamic Response Using the Transmissibility Concept

The dynamic behaviour of a structure can be modelled in various ways. In practice, the response model is often used, through the measurement of frequency response functions (FRFs), as a theoretical or even an analytical model may be very difficult or impossible to establish, reproducing adequately the experimental results. It happens, however, that once in service it may be impossible to take measurements on the structure, as the co-ordinates may no longer be accessible. The concept of transmissibility applied to multiple degree of freedom systems may help in the estimation of the desired FRFs, due to some particular transmissibility properties, a subject that has been published recently by the authors. In this paper the underlying transmissibility theory and the relevant properties are summarised and some experimental examples are given to illustrate the usefulness of the technique.