Issue 51

M.G. Masciotta et alii, Frattura ed Integrità Strutturale, 51 (2020) 423-441; DOI: 10.3221/IGF-ESIS.51.31 437 DS5 f exp f num | Δ f |[%] MAC (  exp,  num ) Mode 1 19.16 17.44 8.97 0.98 0.00 0.00 0.01 Mode 2 43.19 44.11 2.13 0.00 0.79 0.02 0.00 Mode 3 57.54 48.18 16.27 0.07 0.00 0.79 0.10 Mode 4 74.09 61.00 17.67 0.08 0.00 0.00 0.89 Table 8 : Experimental ( f exp ) versus numerical frequencies ( f num ), frequency relative error Δ f and MAC matrix for DS5. Figure 14: Experimental (left) and numerical (right) mode shapes for Damage Scenario DS3 (blue line: front side A01-A13; red line: back side A14-A26). Fig. 16 shows the trend of the arch frequencies over progressive support settlements in the experimental and numerical cases. It appears that the adopted numerical simulation coupling linear perturbation and modal analysis is able to fairly replicate the dynamic behavior of the damaged arch, especially with regard to the mode shapes, while it underestimates for the last DS the frequencies relative to the third and fourth modes. For the sake of completeness, the distribution of the maximum eigenvalue of the fracture strain tensor E f and of the minimum eigenvalue of the Cauchy stress tensor T concerning the last damage scenario (DS5) are displayed in Figs. 17 and 18, further demonstrating the consistency between numerical and experimental crack pattern.