Abstract
A wireless sensor network (WSN) is a network that interconnects distributed devices designed to measure and gather data on various physical phenomena in the surrounding environment. This collected data is then transmitted cooperatively to enable informed decision-making. WSNs have found diverse applications, including in the realms of smart cities and driverless cars, where they play a crucial role. In recent times, structural health monitoring (SHM) systems have gained significant prominence as they are increasingly utilized to assess the structural integrity of bridges and schedule safety maintenance measures to prevent potential collapses. Remote SHM systems have emerged as a popular choice for bridge monitoring, as they eliminate the need for frequent on-site visits and provide real-time data for prompt decision-making. When it comes to instrumenting highway bridges for remote SHM, WSNs present themselves as an optimal design choice. However, despite their potential, WSNs for bridge SHM have mostly remained limited to civil engineering laboratories and have not been extensively deployed in real-world transportation infrastructures. One of the major challenges in implementing WSNs for bridge SHM is the limited battery capacity of sensor hardware, which affects the overall lifetime of the WSN. To address this challenge, several solutions have been proposed to increase the longevity of WSNs. However, it is important to note that WSNs introduce new vulnerabilities, as the unattended and connected sensor nodes become susceptible to both physical and cyber attacks. Implementing countermeasures such as encryption schemes and authentication mechanisms to enhance security further reduces the energy resources of the system, consequently affecting its lifetime. To tackle the unique security and longevity dilemma faced by WSN-SHM systems for bridges, this thesis proposes a novel modeling framework. This framework aims to maximize the lifetime of the system while taking into account important factors such as sensor coverage, connectivity, energy consumption, component reliability, and cyber security. By incorporating these considerations into the modeling process, a new and innovative design of WSN topology is proposed, specifically tailored to the requirements of bridge SHM. The effectiveness of the proposed security modeling and WSN topology design is validated through simulations and prototype implementations. The results obtained from these experiments showcase the readiness and feasibility of WSN-SHM systems for widespread adoption and practical implementation in real-world scenarios.