OMA-based structural health monitoring of a wooden mast structure exposed to ambient vibrations

OMA-based Structural Health Monitoring (SHM) relies on the modal parameters in order to identify the health condition of a structure. These parameters are affected both by structural changes and the varying environmental/operational conditions. In order to robustly detect structural modifications in the monitored structures, an OMA-based SHM approach must distinguish between the different sources of change. Along these lines, this study aims at detecting structural changes in a structure subjected to varying environmental conditions. The investigated structure consists of a wooden mast and a steel frame top site, and is monitored by a modern vibration-based acquisition system while a weather station captures the environmental conditions. The measurements provided are used to: establish an environmental model for the mast structure; remove the effect of the environmental conditions from the estimated modal parameters and finally detect structural changes such as induced damages, hereby assessing the efficiency of the deployed OMA-based SHM approach.