A NOVEL EMBEDDED FIBER OPTIC SENSOR FOR COMPOSITE STRUCTURE CHARACTERIZATION

A COMPREHENSIVE STUDY LEADING TO THE DEVELOPMENT OF A NOVEL TECHNIQUE FOR A SENSITIVE AND INEXPENSIVE EMBEDDED FIBER OPTIC SENSOR IS PROPOSED. THE FIBER OPTIC SENSOR WILL OPERATE ON THE PRINCIPLE OF MODAL POWER DISTRIBUTION (MPD) MODULATION IN MULTIMODE FIBERS CAUSED BY MECHANICAL AND ENVIRONMENTAL DISTRUBANCES IN THE SMART MATERIALS. THE THEORETICAL AND EXPERIMENTAL INVESTIGATION WILL BE DIRECTED TOWARD THE THREE BASIC OBJECTIVES; ADDRESSING THE FUNDAMENTAL FIBEROPTIC SENSOR PERFORMANCE UTILIZING THE MODAL POWER DISTRIBUTION TECHNIQUE, THE PROCESSING-STRUCTURE-SENSOR INTERACTION, AND A COMPOSITE-SENSOR SYSTEM PERFORMANCE EVALUATION. THE STRATEGY FOR THE PROPOSED RESEARCH IS TO USE THE MODAL POWER DISTRIBUTION IN OPTICAL FIBERS AS A HIGHLY SENSITIVE TOOL FOR MEASUREMENTS OF STRUTURAL RESPONSE OF VARIOUS MODES OF PERTURBATION. THIS TECHNIQUE WILL BE APPLIED FOR SENSING THESE PERTURBATIONS BY COMPARATIVE MEASUREMENTS OF MODAL POWER DISTRIBUTION AND SUBSEQUENT REDISTRIBUTION AT THE OUTPUT END OF THE FIBER. IN A PRELIMINARY INVESTIGATION, CARRIED OUT IN THE LAST FEW MONTHS, RESULTS INDICATE THAT THIS DEVELOPED TECHNIQUE IS HIGHLY SENSITIVE, INEXPENSIE, AND WELL SUITED FOR SMART STRUCTURE APPLICATIONS. TO OPTIMIZE THE SENSOR CONFIGURATION, AN EXTENSIVE STUDY OF SENSITIVITY AND DYNAMIC RANGE OF THE SENSOR WILL BE INVESTIGATED. THIS WORK WILL INCLUDE THE DEVELOPMENT OF AN APPROPRIATE MODEL FOR EVALUATION OF EXTERNAL PERTURBATION.