Dynamic characterization and damage identification

This chapter presents selected cases of modal parameter evaluation and damage identification, privileging the applied aspects. The identification of modal parameters is discussed through three experimental cases of masonry structures: a civil building, a monumental structure and a nineteenth century railway bridge. Modal parameters are response quantities that are sensitive to damage, whose variation with respect to an undamaged state can be exploited in view of damage detection and identification. Moreover, the variations of modal quantities can be used for updating the structural model, leading to the best estimate of model mechanical parameters in the undamaged and damaged conditions. This provides information on the damage location and severity. The technique of damage identification based on model updating is applied to laboratory experimental tests on a steel arch.