Monitoring manufacturing of composites using embedded distributed optical fibre sensors

After thermal curing a composite plate or component, it is expected to have residual stresses which might affect the fabrication quality and the mechanical performance of the composite. In the present work, a distributed optical fibre sensor (DOFS) was embedded in a carbon fibre panel, measuring the development of residual stresses by monitoring in real-time the manufacturing process, from the resin infusion to the curing cycle, and the changes experienced within. An optical sensor interrogator detects and measures changes in strain and temperature along the DOFS with high precision and accuracy, making it possible to obtain a full strain/temperature profile. Data acquired from the embedded sensor led to track and characterise the strain profile at every stage of the manufacturing process.