The Effects of Adhesive Geometry and Type on Strain Transfer for Optical Fiber Strain Sensing.

The strain response of both acrylate and polyimide-coated optical fiber strain sensors bonded to aluminum specimens with AE-10, AE-15 and M-Bond 200 strain gage adhesives was investigated with both axial and cantilever beam tests. These results were compared to both the strain response of conventional strain gages and to model predictions. The results indicate that only approximately 82.6% of the known strain in the specimen was transferred through the glue line and fiber coating into the fiber. Thus, multiplying by a strain transfer factor of 1.21 was sufficient to correct the optical fiber strain output. This effect was found to be independent of the optical fiber coating, as well as the adhesive type and the 3D profile of the glue line used to attach the optical fiber. [ABSTRACT FROM AUTHOR]