Structural health continuous monitoring of buildings – A modal parameters identification system

Monitoring systems play a key role in maintaining the buildings' structural health. Although in the last decades the structural monitoring has experienced a considerable growth, the monitoring systems still require remarkable installation efforts and significant costs. Due to these disadvantages, the spread of such systems was scarce, and the duration of experimental phases was often short. The aim of this work is the design of a Structural Health Monitoring (SHM) system to continuously monitor and check the structural behavior throughout the buildings' lifespan. The system, made up of a customized datalogger and slave devices, allows the continuous monitoring of structures' acceleration thanks to its ease of installation and low cost. The proposed system is mainly based on a microcontroller that: i) communicates with the nodes via RS485 bus, ii) synchronizes the acquisition samples, iii) acquires the data measured by the nodes. The system was tested on a cantilever aluminum structure, through three different experimental campaigns and the measured data, collected in an internal memory of the datalogger, were post-processed via Matlab algorithm. The results allowed to evaluate the modal parameters (frequencies, damping and modal shapes) of the analyzed structure and its health.