Flexible smart sensor framework for autonomous full-scale structural health monitoring

The demands of aging infrastructure require effective methods for structural monitoring and maintenance. Wireless smart sensors provide an attractive means for structural health monitoring (SHM) through the utilization of onboard computation to achieve distributed data management. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While much of the technology associated with smart sensors has been available for nearly a decade, there have been limited numbers of full-scale implementations due to the lack of critical hardware and software elements. This research develops a flexible smart sensor framework for full-scale, autonomous SHM that integrates the necessary software and hardware while addressing key implementation requirements. The Imote2 smart sensor platform is employed herein, providing for the first time the enhanced computation and communication resources that support demanding sensor network applications such as SHM of civil infrastructure. A multimetric Imote2 sensor board with onboard signal processing specifically designed for SHM applications has been designed and validated. Flexible network management software combines a sleep/wake cycle for enhanced power efficiency with threshold detection for triggering network wide operations such as synchronized sensing or decentralized modal analysis. A cable-stayed bridge in South Korea serves as one of the test beds for this effort, both informing and driving system development. This research has resulted in the first autonomous, full-scale implementation of a wireless smart sensor network for structural health monitoring.