Investigation of Novel Blade and Foundation Technology

1. 1st Annual Meeting and Presentation to Advisory Board 4th October 2018

2. WP 4. Investigation of novel blade and foundation technology  4.1 Modelling, design and manufacture of novel blade structures 4.2 Embedded sensors for whole lifetime structural monitoring of blades 4.3 Numerical modelling of drag anchors for cable risk assessment 4.4 Improved assessment of installation risks and in-place stability of lightweight inter-array cables for offshore renewable installations

3. Recruitment WP4.1 Modelling, design and manufacture of novel blade structures Research Software Developer due to start 1st Jan. PDRA originally due to start 1 year after the software developer but starting recruitment now. WP4.2 Embedded sensors for whole lifetime structural monitoring of blades PDRA 1 (Integration of optical fibres during manufacture) - due to start on 31st October. PDRA 2 (fibre optic sensors) - Candidate identified and interviewed but need to re-advertise at new band. WP4.3 & WP4.4 Adverts and targeted recruitment ongoingfollowing unsuccessful recruitment round Appointed candidate was unable to take up the position due to health issues Further candidate with correct background should be applying this week

4. Structural optimization - Bio-inspiration WP 4.1 Modelling, design and manufacture of novel blade structures Bones grow and continually adapt in response to mechanical stress. They are optimized to resist a complex combination of many loads. They are strong but lightweight. + + + + + + + +

5. Bone modelling Ultra-high resolution finite element analysis allows us to investigate macro- and micro-level bone geometry. Adaptive remodelling, combining multiple loading scenarios, optimizes the structure. WP 4.1 Modelling, design and manufacture of novel blade structures ΣFi

6. Structural optimization - application to blade design WP 4.1 Modelling, design and manufacture of novel blade structures new core options 3D fully optimised 3D regular lattice 3D irregular lattice +

7. WP 4.1 Modelling, design and manufacture of novel blade structures Identify candidate materials & determine properties Software enhancement – anisotropic materials & optimisation algorithms Identify appropriate blade models – full/sections Establish load cases Structural optimisation Determine manufacturability constraints Identify structural constraints Validate models - existing & new structures Quantify performance improvement

8. WP 4.1 Structural optimisation Discussed with SGRE UK, Hamburg and Denmark. Focus changed from optimisation of inserts (as in proposal) to entire blades (as it offers greater cost saving potential). Initial optimisation will be conducted on public domain reference blade (NREL 100m or Sandia Labs 100m). Design and load case data for both blades obtained and initial processing complete. Next 3 months: Research Software Developer induction and PDRA recruitment Progress against tasks for each Work Package and plan for next 3 months

9. WP 4.2 Embedded sensors for whole lifetime structural monitoring of blades Manufacture Embed ‘nervous system’ of fibre optic strain/temperature sensors Operation Transport and installation Resin infusion Curing temperature Residual stress Multi-axis stress Thermal cycling Impacts Stress history Digital twin Improved lifetime prediction Understanding of manufacture-operation parameter interaction

10. Challenges Focus is on extracting through-life strain and temperature measurements • Identify appropriate sensor and signal processing technologies • Balance spatial and strain/temperature resolution and dynamic range • Balance requirements during manufacture and operation • Robustness to survive manufacture and service • System cost • Optimise number and arrangement of sensors • Direction, depth, redundancy (inc. blade repair) • Develop signal processing techniques to decompose strain and temperature measurements • Integrate into blade manufacturing process • Evaluate system performance WP 4.2 Embedded sensors for whole lifetime structural monitoring of blades

11. Other sensors WP 4.2 Embedded sensors for whole lifetime structural monitoring of blades 2.2. Integrating data from multiple on-turbine sensor networks to detect the most critical failure modes of wind turbine blades Optimal placement of sensors 4.2. Embedded sensors for whole lifetime structural monitoring of blades 2.3 Fibre-optic integrated sensors for blade Structural Health Monitoring Stress models 2.5. Predicting critical failures in wind turbine blades by modelling populations of wind turbines Sensor data Scaled blades Full sized blades? 4.1. Modelling, design and manufacture of novel blade structural inserts

12. WP 4.2 Embedded sensors for whole lifetime structural monitoring of blades Develop resin infusion/curing test rig Evaluate in-manufacture measurement Integrate fibres into manufacturing process Evaluate manufacture on full scale blade Devise and evaluate signal decomposition techniques Define system requirements and constraints Evaluate available sensor systems Assess alternative fibre arrangements Evaluate performance on small scale blade model Field test strain sensors on full scale blade Establish appropriate load, stress and thermal models Liaise with sensor producers Define Test regime UoH and/or LVV (Sheffield)

13. WP 4.2 Embedded Sensors Discussed with SGRE UK, Hamburg and Denmark – primarily focus on manufacturing issues. Working with SGRE to identify kit suitable for bench top composite casting set up. Potential to use equipment from SGRE training centre. Involved additional investigator (Kevin Fancey) with composite manufacture and evaluation expertise. Once PDRAs in Post: Conduct literature review/supplier discussions to assess current fibre optic sensing systems capabilities Identify/procure bench top casting system components Progress against tasks for each Work Package and plan for next 3 months

14. Supervisors: Prof Charles Augarde & Dr Will Coombs, Ørsted Lead: Laurence Cross • Current approaches to determine drag anchor behaviour when assessing the risk to windfarm cables of the anchoring of vessels close to the cable route are often based on outdated anchor penetration models and data from trials undertaken many years ago. Concerns exist that for some types of seabeds (e.g. soft clays) the guidance, on fluke penetration and drag length, could be overconservative. Knowledge of the performance of drag anchors is necessary to assess the risk of damage to cabling laid on or in the seabed. Increasing numbers of offshore installations for renewable energy means increased cabling to carry the electricity to land and hence prompts the need for improved risk assessment procedures. • In this project, advanced numerical modelling will be applied to the problem of drag anchor embedment in the seabed. The numerical modelling will be based on the Material Point Method (MPM), which provides an efficient means to model very large deformations, uses existing finite element technology (e.g. constitutive models for the seabed soils) and is ideal for the modelling of soil-structure interaction. The modelling will be validated against existing field data, and also potentially against laboratory trials at Dundee University. • Two situations will be modelled: (a) “emergency anchoring” where a vessel deploys an anchor while travelling; (b) a moored vessel anchor breakout. WP 4.3 Numerical modelling of drag anchors for cable risk assessment

15. WP 4.3 Numerical modelling of drag anchors for cable risk assessment Potential student identified Undertake a literature review of existing techniques for assessment of the deployment of drag anchors and long-term capacity/breakout potential of anchors for a variety of soil conditions. Make contact with other researchers and possibly anchor manufacturers for data that could be later used for validation of the numerical model. Extend the existing material point method code to include dynamic effects and soil-fluid coupling. Implement a suitable boundary condition enforcement method between the drag anchor and the soil. Begin validation. Progress against tasks for each Work Package and plan for next 3 months

16. Supervisors: Prof Charles Augarde & Dr Will Coombs Particular issues exist with the installation of lightweight cabling for offshore renewables installations, e.g. inter-array lines in certain seabed conditions. Cabling made using low specific gravity materials such as aluminium is often difficult to bend into place in a trench in which the seabed deposits are effectively fluidised due to the trenching operation. The initial stability following installation is then affected by soil settlement above and around the cable, and by vibrations transmitted along the cable. It is currently very difficult to predict behaviour and new tools are needed to avoid problems in the future. In this project, numerical techniques will be developed to model the installation and post-installation of a single representative cable in a soft seabed material WP 4.4 - Improved assessment of installation risks and in-place stability of lightweight inter-array cables for offshore renewable installations

17. Both projects have been scoped and approved with Ørsted. Legal agreements will be put in place once all projects have been defined A related PhD student started on the 1st October 2018 on a Mexican government scholarship. Research on one of the projects from the initial funding application that was not taken forward as part of this project after discussions with Ørsted. The student will be developing constitutive models for seabed sediments that are on the boundary of conventional soil mechanics.   WP 4.3/4.4

18. Risks PDRA/PhD student Recruitment WP 4.1 Ability to source components for sensor system and bench top casting rig within budget Opportunities Link to Supergen ORE Hub and other projects for improved loading models for larger blades Risks and Opportunities

19. Supergen ORE Hub £5M (+ potential further £4M) funding to support fundamental research in Wave, Offshore Wind and Tidal Energy Looking at future large scale deployment scenarios, ‘virtual sites’, modelling and design techniques with emphasis on floating structures Opportunities to shape and respond to future flex funding calls Outcomes and Outputs