MDR Vacation bursary project: Repair Methodologies for Composite Materials
by Anna McIlwaine
By Anna Pascale Mcilwaine, undergraduate student , Faculty of Engineering and the Environment
I’m a 3rd year Ship Scientist at the University of Southampton. After my interest in composite materials was sparked during an individual project focused on the subject, I decided to further my knowledge on the subject through a research internship.
Composites are becoming increasingly popular in industry, particularly the marine industry, as their applications widen due to the increased levels of research into their mechanical behaviour is carried out. Within this, Sandwich Structures are greatly favoured due to their high stiffness to weight ratio, high energy absorption capability and buoyancy. They are often used in the place of metals such as aluminium alloys or steels due to their increased 2nd moment of area and resistance to bending without any weight penalty.
Damage to these composite structures is almost inevitable due to them being exposed to extreme conditions in the marine environment. This damage may be caused by growth of a defect produced in manufacture, impact whilst in service, long term water exposure or excessive wear or loading. This is why it is crucial that repair methodologies of composites are developed in order to allow the structure to perform with its original structural integrity. It is hoped that through this research project conclusions will be made that will aid the design and implementation of future composite repairs.
The project is closely linked with the RNLI and aims to closely follow their repair specifications to allow the findings to be as applicable to industry as possible. During the research project comparisons will be made between a traditional wet lay-up repair, which is commonly used at the moment and a Glass Structural SPRINT repair. SPRINT repairs have the capability of saving time and hence money in industry. Hence it is envisaged that this project can go some way to proving the structural competence of SPRINT compared to a wet lay-up.
The stresses and strains within the repairs and the surrounding area will be analysed using strain based and non-destructive testing techniques, namely Digital Image Correlation and Thermoelastic Stress Analysis which is based on measurements using an IR detector. The aim being to assess which technique is more effective in judging the quality of the repair.
Following on from this research internship I will be back at the University of Southampton to study for a masters in Ship Science. Through this I will be partaking in a group design project of a Paralympic Va’a canoe. I hope to be able to apply the knowledge I have gained through working with composites to the design, providing it with an advantage against its competitors.
I would like to express a huge thank you to DIAB and the RNLI for their support of this project. Without their generous donations of materials and ongoing advice and expertise it would not be possible.
Categories: Blog. Tags: Anna Pascale Mcilwaine, composites, epsrc, Professor Janice Barton, Repair methodologies for composite materials, Ship Science, and vacation bursary. Project names: Repair Methodologies for Composite Materials.