Using Enhanced Cepstral Analysis for Structural Health Monitoring

Mel-Frequency Cepstral Coefficients (MFCCs) have been proved to be via-ble to detect damage-induced shifts in the frequency content of structures subjected to external forces. Nevertheless, the Melodic (Mel) Scale is a per-ceptual feature, roughly based on human perception and originally formulat-ed to resemble the biological mechanisms of the auditory apparatus. Thus, its straight application to non-auditive acquisition systems may be misleading. However, the intrinsic basilar assumption – that is, a nonlinear, non-constant spacing between filters in the frequency domain – is promising for the time-frequency analysis of structural dynamic behaviour. Here, an ensemble of related techniques, developed departing from the original approach, is de-scribed; different features, filter types and filter spacing have been investi-gated. Candidates are compared to each other and benchmarked against the previous approaches present in Literature on the challenging Case Study of the Fossano Bell Tower, considering realistic damage scenarios.