Article Article
In-process Monitoring of Advanced Composites with a Reusable Thin Film

Composites offer significant structural and aerodynamic advantages to aerospace and automotive vehicles. In addition, there are environmental and cost-saving advantages over traditional metal structures due to reduced fuel consumption and increased service life. One of the main concerns for the composite industry is that current composite manufacturing processes cannot provide fast enough cycle time to match metal alloy processes. Thus, an advanced research work is needed to develop technology that will reduce the timeline required for production and assessment of such materials. One area of concern is the formation of process-induced defects in composite structural parts during various production stages. Another concern is the proper monitoring of the curing cycle of the manufactured part. To tackle such challenges, a reusable in-situ cure monitoring and assessment system that can predict the formation of manufacturing defects and monitor the degree of cure is developed. Using Lamb waves, initial results indicate that certain characteristics of ultrasound waves have the potential to serve as an index for estimating the degree of cure and level of defects. The proposed system could be used under any curing environment in an autoclave, an oven, or out-of-autoclave process. Off-the-shelf actuators and sensors are be embedded in a reusable thin film material that withstands severe conditions and that temporarily adheres to the manufactured part creating an effective electromechanical coupling between the transducer and the laminate. Experimental and computational results have proved the feasibility of using such a reusable film in cure monitoring and damage detection of complex composite structures.


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