Design of a wireless active sensing unit for structural health monitoring

Many academic and commercial researchers are exploring the design and deployment of wireless sensors that can be used for structural monitoring. The concept of intelligent wireless sensors can be further extended to include actuation capabilities. In this study, the design of a wireless sensing unit that has the capability to command active sensors and actuators is proposed for structural monitoring applications. Active sensors are sensors that can input excitations into a structural system and simultaneously monitor the corresponding system's response. The computational core of the wireless active sensing unit is capable of interrogating response data in real time and can be used to execute embedded damage detection analyses. With high-order vibration modes of structural elements exhibiting greater sensitivity to damage than global structural modes, wireless active sensors can play a major role in a structural health monitoring system because they are capable of exciting high-order modes. A computational framework for analyzing piezoelectric based active sensor signals for indications of structural damage is proposed. For illustration, a simple aluminum plate with piezoelectric active sensors mounted to its surface is used.