Local diagnoses in modal analysis through additional poles

The main scope of this article is to show how certain additional poles of a structural system, other than the classical ones, can be measured and considered within the area of structural dynamics such as for example damage detection and model updating; such poles can enrich the intrinsic modal database of the system and even be used to analyze the structure in a local sense. Such poles can be extracted by using certain response-based frequency response functions (R-FRFs) which do not require the measurement of exciting forces. Therefore, the objective of the present article is multiple because (i) the potential of certain FRFs is illustrated in the realm of structural dynamics along with the possibility to (ii) increase a privileged data-base (poles) through which (iii) local analyses of a structure can be carried out. Numerical simulations test the theoretical findings and show the ability of such additional poles to carry out local diagnoses on structural systems generally through a higher sensitivity than that of classical poles.