Issue 48

R. S. Y. R. C. Silva et alii, Frattura ed Integrità Strutturale, 48 (2019) 693-705; DOI: 10.3221/IGF-ESIS.48.65 698 Before the progressive damage was artificially introduced, a reference Ambient Vibration Test was conducted for 20 minutes in 10 locations of the bridge span. The total number of samples acquired was 475,341 (≈4.75x10 5 samples). The identification of the frequencies and mode shapes was performed using the Frequency Domain Decomposition (FDD) method available in the ARTeMIS software [16]. Fig. 4 illustrates the first four modes of shapes of the undamaged bridge structure. Fig. 5 shows the curves of the average normalized singular values of the spectral density matrices of all experimental setups. Fig. 6 shows the values of the Auto MAC correlation matrix of the experimental mode shapes obtained by the application of the FDD method. Figure 5 : FDD method: average normalized singular values of the spectral density matrices. Figure 6 : AutoMAC correlation matrix of experimental mode shapes using the FDD method. Damage cases The experimental campaign had seven progressive damage cases. However, this paper presents the results of only one experimental damage case. Moreover, this research also presents numerically simulated damage cases to show the