Optical fiber for mechanical strain sensing

Abstract

Fiber optic sensors have been widely used in the different aspects of engineering such as civil, mechanical and biological etc. The conventional Fiber is made of glass with a single core and a cladding. With the advancement of technology, Microstructured Polymer Optical Fiber (MPOF) was introduced in 2001. The new Fiber is more cost Effective to produce with more precise manufacturing techniques enabling the manipulation of the Structure. MPOF Fibers may begin to replace glass Fibers in some areas in the years to come. In this project, a halogen Light source supplies Light through an Optical Fiber which is coupled together with a Fiber optic spectrometer to detect the amount of Light loss when the specimen is subjected to increasing strain. The amount of Light loss is measured in terms of relative intensity. Three types of Experiments were conducted for glass Fiber and MPOF to investigate the relationship between loss and Loading and loss and Displacement. The three Experiments conducted are Tensile Test, Three Point Bending Test and Curvature Bending Test. The Results obtained from the Experiment show that even though the amount of Light loss is in an increasing fluctuating pattern, a linear relationship can be obtained from the data plot. Hence using the linear relationship from the Experiment, the amount of transmission Losses between glass Fiber and MPOF could be compared.