Carbon epoxy composite curing process monitoring using high resolution optical fiber sensors

Within this work, we present a novel approach for Structural Health Monitoring (SHM) of composite materials during the autoclave curing process. For this research, samples of Carbon Fiber Reinforced Polymer (CFRP) have been manufactured with optical fibers embedded, both in the middle of the stack and on its surface. The strain development of the CFRP during the curing process has been monitored employing the Optical Frequency Domain Reflectometry (OFDR) technique. This technique allows the conditions of the element to be tracked not only during the operational lifetime of the composite, as in most of the research in this field, but also throughout the manufacturing process. The reported measurements demonstrate the potential of distributed optical fiber sensors for monitoring CFRP structures while their manufacturing, providing a unique opportunity for early detection of damages that may result in critical failures (e.g. delamination and debonding) and for improving the quality of the manufacturing processes and the final strength of the product.