Evaluating the erosion-corrosion-fatigue properties of WAAM built components and how to optimise them for the marine environment

With the increasing interest in a green transition to Net Zero, offshore renewable energy is becoming a big focus for many countries. There are hundreds of offshore wind turbines which are coming to the end of their 25-30-year lifecycle and many developers are looking into life extension options to maximise their assets. The structures for offshore renewables are subject to some of the harshest environments in the world, with loading from wind, wave, and tides in a corrosive and erosive environment. Additive Manufacturing (AM) has shown great promise for use in the marine environment. However, little research or application of the technology has been done within the sector. Corrosion is seen as one of the biggest threats to offshore structures and can be accelerated with the presence of erosion. AM has the potential to mix different materials to improve the properties of the end part. Wire Arc Additive Manufacturing (WAAM) has shown great promise due to the ability to create large components, in short lead times, with little defects compared to traditional manufacturing processes. The process allows for easy manufacture at ports or yards near offshore sites and therefore has the potential to create components with shorter lead times compared to traditional supply chain routes. Early research into the potential of using WAAM to create corrosion resistance coatings and components has highlighted the processes' many benefits but further research is required to justify the use of the processes for commercial applications. In terms of wear resistance even less research has been conducted but initial findings show that there is a greater resistance compared to the wrought material. The aim of this study is to thoroughly review the state-of-the-art on the use of AM for erosion and corrosion resistance of engineering structures with the focus on offshore renewable energy structures. The findings from this study help to identify the gap in the knowledge for future research to commercialise the AM application within the offshore industry.

This outward-facing doctoral training centre will create impact through knowledge enhancement and leadership development which will have significant benefit for society, people and the economy.

Societal Impacts:
A very large increase in renewable energy generation, mainly wind, wave and tidal, is expected in the coming years and decades to meet the UK Government and international obligations to reducing greenhouse gas emissions by at least 80 per cent by 2050 when compared to 1990 levels. In particular, the Offshore Wind Industry Council is proposing, under a Sector Deal, to deliver 30GW of offshore wind by 2030 and 50GW by 2050, whilst reducing the average price of electricity by 18%. The longer term societal and economic impacts arise from the difference that the CDT programme and its graduates make to the UK realising this medium-term and longer-term target. The societal impact of meeting these targets, over failing to meet them, can be calculated in avoided CO2, increased sustainability, security and resilience of the energy system in a safe, affordable and environmentally sensitive manner.

People Pipeline and Skills:
There is a widely recognised skills gap in renewable energy both in UK and Europe. Hence, the proposed CDT is timely contributing significantly to meeting the sector's skills demand by the provision of highly trained engineering leaders, expert in a broad range of wind and marine energy technologies and engineering. Most of the CDT graduates will be expected to take up posts in the growing commercial wind and marine energy sectors, and quickly rise to positions of leadership and influence. Some graduates will remain in the higher-education sector and develop academic careers providing much needed increased capacity and capability resulting in a positive impact through an expanded research-base and capability to deal with the inevitable research challenges of the sector as it develops further commercially.

Students will be mentored and encouraged to take a proactive role in creating impact with their research whilst observing Responsible Research and Innovation (RRI). All the Universities participating in this CDT proposal have explicit policies and resources in place to support knowledge exchange and impact and also public engagement. These support the students throughout their studies to engage in broader dialogue and deliberation and to be aware of the potential impacts and implications of their research.

Our CDT students will also engage in outreach activities and impact the wider community through the well-established Professional Engineering Training Scheme (PETS): this scheme is managed and directed by the students and provides opportunities to engage in outreach activities and to work with peers. e.g. PETS runs a schools and colleges programme wherein the students organise visits to schools and colleges to provide information about renewable energy and a basic introduction to the technology involved.

Economic Impact:
The low-carbon and renewable energy sector is estimated to increase five-fold by 2030, potentially bringing two million jobs to the UK. In particular, an ambitious Sector Deal for industry proposed by Government as part of its Clean Growth Strategy could see a total installed capacity of 30 GW of offshore wind by 2030 with the potential to create at least 50,000 jobs across the UK. If achieved, this would be a six fold increase from the current installed capacity and would make offshore wind the largest source of domestic electricity. To ensure resilience, it is also important to retain and develop the leading UK Wave and Tidal position. With the direct and indirect value added to the UK supply and installation chain in terms of job creation, intellectual property exploitation, and sales of wind, wave and tidal technology and services, the proposed CDT will make an important contribution through knowledge enhancement and leadership development.