Instantaneous Spectral Entropy: An Application for the Online Monitoring of Multi-Storey Frame Structures

Damage assessment techniques based on entropy measurements have been recently proposed for the structural health monitoring of civil structures and infrastructures. A quasi-real-time approach, based on the use of instantaneous spectral entropy (ISE) over an uninterrupted stream of data, is discussed here. The methodology is proposed for the detection of sudden damage-related structural changes (more specifically, linear stiffness reductions and nonlinear breathing cracks). The method operates by framing the continuous stream of vibration signals and comparing the single frames to a known baseline. The approach is also suitable for nonstationary signals originating from nonlinearly behaving structures. The procedure is validated on an experimental benchmark: a laboratory-scaled model of a three-storey single-span frame metallic structure. Three different definitions of entropy and six candidate time-frequency/time-scale transforms have been tested to find the optimal settings.

Automated summary

This article presents a damage assessment technique based on entropy measurements for structural health monitoring of civil structures and infrastructures. The method utilizes instantaneous spectral entropy to detect sudden structural changes and operates by comparing frames of vibration signals to a known baseline.