Real-time through-thickness and in-plane strain measurement in carbon fibre reinforced polymer composites using planar optical Bragg gratings

This is an ICASE award sponsored by BAE Systems

Recent colloboration between the Optoelectronics Research Centre at the University of Southampton and the Composites Insitute at the University of Bristol has developed a new type of optical sensor [1]. The sensor is based upon an ultra-thin glass wafer (50um thick). This can be connected to regular optical fibre and embedded into composite material without compromising mechanical integrity. Furthermore, it uniquely provides in-plane and through-thickness strain information.

This PhD project would therefore use this new sensor platform to infer residual stress during VARTM manufacture and additionally probe the refractive index of the composite’s resin e.g. for water ingress. These new capabilities offer routes for tailored composite manufacture and higher fidelity digital twin models.

Along with demonstrating real time impact and structural health monitoring, the PhD will also explore the manufacturability and resultant long-term reliability of an embedded optical sensing solution and its fragility to impact / environmental events.[1] Christopher Holmes, Mike Godfrey, Daniel John Bull, Janice Dulieu-Barton, ‘Real-time through-thickness and in-plane strain measurement in carbon fibre reinforced polymer composites using planar optical Bragg gratings’, Optics and Lasers in Engineering, Volume 133, 106111, (2020).

How to apply