Low stiffness variation in structural systems: identification and localization

When a very low damage occurs, the undamaged structural response totally overlaps the damaged one eitherintimedomainorinfrequencydomain;ontheotherhand,byconsideringsomecharacteristicsofthe analytical signal, such as the phase, it has been possible to develop a damage identification procedure that allows the identification and localization of damage even if the structure experiences multiple damages at the same time. This procedure is also robust with respect to the presence of measuring noise. In order to assess the validity of the proposed damage identification procedure, numerical applications on single degree of freedom and 2 DOF and 4 DOF are presented using data records perturbed by measuring noise too.