Monitoring Strain During Composite Manufacturing using Embedded Distributed Optical Fiber Sensing
Short Summary
We use high resolution distributed fiber optic sensing to monitor the strain in a composite sample during a VARTM manufacturing process. This work illustrates that distributed fiber sensing can be used to monitor composite structures during the manufacturing process to determine strain levels, monitor infusion and detect defects. The embedded sensors can then further be used to measure strain during load tests of the structure or in-service after manufacture, providing an integrated method for non-destructive testing.
Abstract
We use high resolution distributed fiber optic sensing to monitor the strain in a composite sample during a VARTM manufacturing process. A simple telecommunications-grade optical fiber embedded in the composite sample functions as a distributed strain sensor. The amplitude and phase of light reflected from the fibers are measured using a commercial optical frequency domain reflectometer (OFDR). Changes in the amplitude and phase of the backscattered light were measured and used to determine the strain along the entire length of the composite sample. Measurements were taken with 2 to 5 millimeter resolution along the sample length, illuminating the strains in the composite structure and the effects of resin infusion during the manufacturing process. The embedded fibers were then used to measure the strain in the sample loaded in a cantilever beam configuration. This work illustrates that distributed fiber sensing can be used to monitor composite structures during the manufacturing process to determine strain levels, monitor infusion and detect defects. The embedded sensors can then further be used to measure strain during load tests of the structure or in-service after manufacture, providing an integrated method for non-destructive testing.
Citation
D. K. Gifford et al., “Monitoring Strain During Composite Manufacturing Using Embedded Distributed Optical Fiber Sensing,” SAMPE Technical Conf. Proc., Long Beach, CA, 2011.
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