Adaptable integrated SHM system for metallic and composite structures

Integrated structural health monitoring (SHM) system suitable for continuous use in industrial applications is presented in this research. The system integrates piezoelectric actuator and sensing technique with wireless data transfer, energy harvesting, online data check and signal analysis. The low power production of the local energy harvesting dominates both designing of the components as well as the basic operating principle of the integrated system. Generally the signal analysis methods used with Lamb wave based applications for structure diagnostics require both collecting a large number of data samples and relatively high computational capacity. This makes the SHM systems difficult to use on-line. In our system, only some key features from the piezoelectric sensor response to Lamb waves were measured and the original signal was reconstructed from those features. Simple and computationally effective signal processing, damage detection and analysis methods (e.g. correlation analysis) were then applied for the purpose of determining the condition of the structure. Demonstration of the independent components of the integrated system was successfully conducted including the piezoelectric actuator-sensor subsystem, sensor signal analysis, energy harvesting from vibration of the structure and wireless data transfer. The research further aims for the design and demonstration of an integrated system that can be tailored for specific applications in metallic and composite structures. (5 refs.)