Frequencies identification from ambient vibration data in a masonry heritage building

Abstract

In this paper, we applied an Horizontal to Vertical (HV) spectral ratio analysis to ambient vibration data aiming at the preliminary seismic response identification of a masonry building, characterized by a significant complexity in terms of geometry and elevation. The building is monitored in the aim of the PON01-02710 MASSIMO project. We performed other standard Fourier analyses computing the Power Spectral density (PSD) and the Cross-Power Spectral Density (CPSD) of the signals. The obtained results demonstrates how HV may be very useful for a rapid screening of buildings in those complex cases such as structures belonging to the cultural heritages, and we concluded that noise measurements may indeed contribute to a detailed real dynamic response definition of a system. However, another main objective of this study is the integration of the results obtained by means of the classical aforementioned Fourier analysis techniques with those coming from the application of time-frequencies analyses: the Short-Time Fourier Transform (STFT) and the complex wavelet transform (CWT) which uses the modified complex Morlet function. In fact, there are few case studies of joint application of these different techniques to masonry heritages. Thus, the study provides the opportunity for integrating them and primarily, for exploring capabilities of wavelet transform in Structural Health Monitoring (SHM).