Mechanical performance characterization of rotating shaft using fibre Bragg grating sensors

The analysis of mechanical performance of a rotating shaft has been commonly measured with strain gauges attached with slip ring or telemetry. Nevertheless, strain gauges are bulky for its size which provides limited number of installations when load distribution at smaller dimensional gap is very crucial. Optical Fibre Bragg Grating (FBG) sensor becomes the substitute and more conventional method when it comes to measuring strain. Its size makes it possible to analyze strain in smaller gaps and unlike electrical sensors, it is also immune to electromagnetic interference. In this paper, a study of mechanical performance of the rotating shaft is done by using FBG sensors and rotary optical coupler, which allows transmission of light from the Amplified Spontaneous Emission (ASE) Source to the FBG sensor. In the earlier studies, there is a pre-evaluation of sensitivity of FBG sensors through the study of strain gauge. Although the general bare FBG has 1.2 pm/με, the current sensitivity is 0.712 pm/με The result comparison of the experiment such as deformation is done by using simulation values obtained through Finite Element Analysis (FEA) using the ANSYS Workbench software. The FEA was meshed with different sizes from 3.5 to 0.55 mm. The convergence graph is illustrated and found that 0.75 mm is adequate to be applied for simulation analysis. The obtained result of experimental stress and strain are compared to simulated stationary shaft to have a percentage error ranging from 20-28.87%. On the other hand, the rotating shaft results are discussed as future works are recommended for better improvements of results.