Environmental impact assessment of guided wave-based structural health monitoring

Guided wave-based structural health monitoring (GW-SHM) relies on permanently installed sensors to detect and monitor structural defects such as cracks or delamination. Millimeter to centimeter-sized defects are detected over areas of several square meters with sparse sensor networks installed on metallic or composite structures. So far, the main drivers of the development of such technologies have been expectations of cost savings and/or an increased safety. As monitoring requires a complex cyber physical system including, at least an energy source, sensors, data acquisition, treatment, and communication capabilities, adding monitoring capabilities to a structure leads to an intrinsic environmental impact. This paper targets for the first time the environmental assessment of GW-SHM. Such analysis being use-case dependent, two prospective applications are studied: railroad monitoring and wind turbine monitoring. A complete GW-SHM system prototype is defined to quantify its environmental impact, and exploitation scenarios are proposed to estimate the potential environmental gains provided by the monitoring. For the scenarios under consideration, the studied system is found to be either carbon neutral or carbon negative (i.e., favorable), but this result is limited to the functional units under consideration. The present study is expected to be a template for further environmental assessments of monitoring systems, which shall be conducted for each prospective application and refined often as systems mature and exploitation scenarios become clearer and exploitation data available.