Issue 49

E.U.L. Palechor et alii, Frattura ed Integrità Strutturale, 49 (2019) 614-629; DOI: 10.3221/IGF-ESIS.49.56 623 Figure 17 : Spectrum of accelerations. Figure 18 : Spectrum of accelerations after interpolation. In other words, the technique of signal interpolation in the frequency domain is very effective and practical because it does not add noise to the signal. In this way generating a decrease in the frequency ranges and a better approximation of the actual frequency of the structure can be achieved. After the exponential window was applied to the time signals x (t), the FFT was calculated. In the frequency domain, the peaks corresponding to the first natural frequency of the structure are identified. Fig. 19 shows the spectrum of frequencies windowed with the spectrum frequency without the application of the exponential window. Noise reduction and signal stabilization are clearly visible due to the use of the exponential window. Amplitude Zero Vector T Time Signal Acceleration  Time (s)