Design of wireless sensor network based structural health monitoring systems

Structural health monitoring (SHM) is the science of assessing the integrity of structures such as buildings, bridges and aerospace structures. More specifically, SHM systems strive to detect and locate damage in structures as early as possible. While SHM is a mature area of research and spans several decades and an immense volume of literature, even today, it continues to be an active area of research. The compelling vision of SHM is automatic monitoring systems that continually monitor structures for several years without any human intervention.; Most automated SHM systems today, are essentially data acquisition systems that incur high installation, maintenance and cabling cost. It has been suggested that wireless sensing can potentially bring about a dramatic reduction in cost by doing away with the cabling cost and bringing a significant reduction in installation and maintenance efforts. Self-organizing dense wireless sensor networks that are cheap and easy to install can potentially bring significant benefits to SHM systems.; This thesis examines the various issues involved in crafting a wireless sensor network based system for structural health monitoring. It starts by examining the requirements and constraints imposed by SHM applications, and analyzing how they might influence the design of a sensor network based system. The thesis provides an overview of the existing wireless sensor network based systems and suggests methods of improving these systems. It then describes the design, implementation and deployment of NETSHM, a wireless sensor network based SHM system that can be programmed by SHM engineers without having to delve into the intricacies of the underlying sensor network. Wireless communication in energy constrained sensor network platforms is an expensive commodity and can significantly effect the longevity of the network. The thesis finally proposes novel damage detection and localization methods that are specifically designed to minimize the communication overhead by leveraging local computation at the sensor nodes.