Through-Life Design, Inspection and Repair of Marine Composite Materials

The behaviour of composite materials in harsh, marine environments is still not well understood, and predictability of composite lifetime fatigue performance is low. As a result, repair protocols are very conservative with frequent maintenance interventions and a high rate of part replacement.

This project will work on the development of monitoring protocols and life cycle prediction software for composites used in marine environments. The specific composites in question will be laminated glass- and carbon- fibre reinforced epoxy and polyester/vinyl ester components. This will include research and evaluation of current monitoring technologies used for all materials (and hence their adaptability to composites), before testing specific commercial-type composites using ultrasound scanning, and validating the correct diagnosis of onset of fatigue via these scans.

The types of composite response monitored will include the effects of operational mechanical stress, vibration, delamination, thermal expansion, and water ingress. Once a complete knowledge of all possible types of loading and their diagnostic signs are established, then formal testing on specimens will occur both locally and at a partner's industrial setting with a focus on their existing assets.

Should these tests be successful, a complete monitoring methodology will be proposed for the life maintenance of marine composites, with the aim of significantly reducing expenditure in the field and preventing catastrophic structural failures. It is also planned to develop computer software to predict composite performance over long periods of time, before validating the model with tests on parts exposed to calibrated damage and then implementing these models to predict the use life and repair state of particular field components/structures.