Effect of Damage by Notches in the Vibration Response of Homogeneous and Heterogeneous Beam Models

This paper aims to analyze the dynamic behavior of structural components affected by deep localized damage. In order to obtain frequency values at different degrees of damage, beam models undamaged and damaged by notches were tested through free vibration tests. The experimentations are performed both with homogeneous beam model and reinforced concrete (RC) beam. The beam models have been notched with different damage degree; the damages have been concentrated at the midspan zone. The experimental campaign is organized with the aim to obtain the envelope of frequency response functions (FRFs), that is elaborated and correlated to the degree of damage both for homogeneous and for RC beam models. The behavior of beams with notches under free vibration has been also studied adopting finite element method (FEM). The numerical analysis has been developed assuming boundary conditions adopted in the tests: simply supported beam for homogeneous model and with free-free ends for RC beam model. Finally, it shows a comparison of experimental and theoretical outcomes.