MAPPING DEFORMATION BY PHOTONIC GUIDED-PATH TOMOGRAPHY

Abstract

Deformation measurement systems are very important in the field of health monitoring of structures in a range of engineering industries including the aerospace, civil, automotive, and marine sector. Recently, the trend is toward applying distributed sensing system that are capable to perform deformation mapping of the surface of interest. Some such systems have been demonstrated, mostly using X-rays. However, they are relatively expensive and complicated.This paper reports on the design and implementation of a Guided Path Tomography (GPT) deformation sensor based on plastic optical fiber (POF), which is simple and inexpensive, and is capable of imaging deformation on non-planar surfaces. Inexpensive intensity-based POF strain sensor is manufactured by a simple method, i.e. making 75 grooves of 0.1mm depth, 1cm apart along the central section of 3m long POFs. A full set of 32 POF strain sensor channels was configured as a sensor mat for GPT imaging of deformation.It is shown that using this sensor the images of deformation that is represented by the curved surface of the sensor mat with a variety of loads can be reconstructed using the ART algorithm