Optical fiber sensor system embedded in a member subject to relatively arbitrary loads

A method of solution to the general problem of the behavior of a Mach-Zehnder type optical fiber sensor system (OFSS) embedded in a noncircular cross-sectioned solid structural member is presented. The member is subject to relatively arbitrary loads and their combinations including axial tension, bending, and uniform lateral pressure. The discussion is based on influence region analysis. The expressions for the axial and bending load induced fiber strains are simplified within 99% accuracy. The sensitivity of a three-fiber system is studied by comparing six different cases of coating material combinations, and some conclusions useful in fiber sensor design are reached. The entire work is performed under the regime of linear elasticity.