Fiber Optic Sensors for Strain Measurement in Asphalt Pavements Containing Wireless Pads

Inductive Power Transfer (IPT) is a safe, convenient, and reliable technology for wireless charging of Electric Vehicles (EVs). However, there are many pavement infrastructure issues that require consideration before a working system can be appropriately installed into a pavement system. To achieve this objective requires new pavement instrumentation methodologies to obtain the strain response of asphalt pavements with embedded IPT pads under cyclic traffic loading. In pavement strain data is required to understand the damage mechanisms of the IPT pavement system and predict its combined system life. Fiber Bragg Grating (FBG) sensors have advantages over other sensing technologies that enable them to measure pavement strain within the intense magnetic field of a high-frequency wireless power transfer system. The main objective of this study was to verify in the laboratory the accuracy of the proposed FBG sensor by conducting dynamic flexural tests using a four-point bending apparatus. This sensing technology is intended to be used in an Accelerated Pavement Testing (APT) program to study the mechanical performance of a combined IPT pad-asphalt pavement system. The results of this study show the current FBG sensor is sufficiently accurate and reliable to be used for strain measurement of asphalt pavements containing IPT pads under APT loading.