RF displacement and strain sensing system for wireless structural health monitoring

Structural health monitoring (SHM) is a technology with worldwide interest that is vital to ensure the reliability of any structure while also protecting the safety of human life. Over the years, a lot of research has been conducted on this topic, proposing SHM methods that may be instrumental in understanding the condition of critical parts of a structure. These methods generally rely on wired and/or active technologies, which are not preferable since the wires disallow telemetric measurements and mean increased weight and space, while the active technologies require electric power in order to operate. Two of the most important damage indices of a building structure such as a reinforcing bar (rebar) are the strain and displacement forming either with time or a sudden impact like an earthquake.