1. A few reminders of structural dynamics

Before getting down to the nitty-gritty of dynamic testing, it is worth recalling, albeit briefly, some of the theory behind it. For a more detailed description of the equations in general, and of the effective parameters in particular, please refer to the references [1] and [2] , of which the following paragraph is merely a practical summary recalling the essential elements.

Of all the ways of modeling the dynamic behavior of a structure, the modal superposition approach is currently one of the most widely used. The structure under study is represented as a superposition of simple one-degree-of-freedom models.