Sensing Sheet: The Response of Full-Bridge Unit Sensors to Thermal Variations and the Development of a Prototype

Abstract

Increasing concerns regarding the conditions of civil structures and infrastructure give rise to the need for efficient strategies to identify and repair structural anomalies. Sensing sheets based on large-area electronics consist of a dense array of unit strain sensors. This new technology is an effective and affordable monitoring tool that can identify, localize and quantify surface damage in structures. This research contributes to their development by investigating the response of full-bridge unit sensors to thermal variations and creating a sensing sheet prototype. Overall, this thesis quantifies the effects of temperature on thin-film full-bridge strain sensors monitoring uncracked and cracked concrete. Furthermore, an empirical formula is developed to estimate crack width given an observed strain change and a measured temperature change. Finally, the first sensing sheet prototype is successfully developed and shown to accurately monitor structural strain changes.