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Projects: Projects for Investigator
Reference Number	NIA_NGGT0189
Title	HyNTS Defect Fatigue Behaviour
Status	Started
Energy Categories	Hydrogen and Fuel Cells(Hydrogen, Other infrastructure and systems R&D) 100%;
Research Types	Applied Research and Development 100%
Science and Technology Fields	PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 90%; ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 10%;
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Project Contact No email address given National Grid Gas Transmission
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 September 2022
End Date	31 March 2026
Duration	ENA months
Total Grant Value	£107,500
Industrial Sectors	Energy
Region	London
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , National Grid Gas Transmission (100.000%)
Web Site	https://smarter.energynetworks.org/projects/NIA_NGGT0189
Objectives	The aim of this PhD research project is to investigate and model the effect of hydrogen on the fatigue behaviour of steel, cast iron and brass when these metallic materials are weakened by defects of different size and shape. This will be achieved by running a comprehensive experimental investigation involving hydrogen-soaked specimens that contain artificially manufactured defects. In parallel, a complex, multi-physics body of knowledge will be assembled to lay the foundations for a novel scientific paradigm that will give rise to a transformative way of assessing fatigue damage in metallic components working in hydrogenous environment. The specimens being used to implement the present project will contain artificial defects manufactured by drilling superficial holes having diameter and depth ranging between 0.05 mm and 2 mm. The specimens will be soaked in hydrogen gas at pressures of 10 bar for up to 9 months by using custom-build pressure vessels manufactured by Gilwood (Fabricators) Company Ltd that are rated up to a maximum pressure of 90 bar. Force controlled fatigue results will be generated by testing as-machined and hydrogen-soaked specimens under a load ratio (R=smin/smax) equal to 0.1. This will allow the PhD student to investigate the fatigue behaviour of the tested metallic materials by considering the combined effect of defects, hydrogen and superimposed static stresses (mean stress effect in fatigue). The experimental results being generated according to the above testing protocol will be used to assess and quantify the accuracy and reliability of an advanced structural health monitoring technique that will be developed and implemented by the PhD student as a part of his/her research project. This technique will be developed by combining Linear Elastic Fracture Mechanics, notch mechanics, finite element modelling, and advanced fatigue assessment knowledge. The unique features of the disruptive approach being formulated and validated via this PhD project will facilitate industrial uptake of the new scientific/technical knowledge being gained (through improved damage tolerance arguments) and its subsequent standardisation.  The outcomes from this PhD project will support National Grid in preparing the UKs gas grid for a safe switchover from using methane natural gas to zero carbon hydrogen. Data Quality Statement (DQS): The project will be delivered under the NIA framework in line with the agreed Energy Networks Innovation Process document NGGT internal policies. Data produced as part of this project will be subject to quality assurance to ensure that the information produced with each deliverable is accurate to the best of our knowledge and sources of information are appropriately documented. All deliverables and project outputs will be stored on our internal SharePoint platform ensuring backup and version management. Relevant project documentation and reports will also be made available on the ENA Smarter Networks Portal and dissemination material will be shared with the relevant stakeholders. Measurement Quality Statement (MQS): The project is rated low in the common assessment framework detailed in the ENIP document after assessing the total project value, the progression through the TRL levels, the number of project delivery partners and the medium level of data assumptions. No additional peer review is required for this project. This project covers the combination of empirical and theoretical means of assessing the fatigue performance of pipeline steels and other NTS assets. Fatigue performance will be assessed with regards to the pipe properties including but not limited to: steel grade, age, wall thickness, presence of defects, pipe type and material properties. Comparing empirical findings to theoretical models will allow for extrapolation of findings across the asset population which will ultimately contribute to the fitness-for-service assessment to assess pipeline suitability for hydrogen service. As noted above, the aim of the research is to assess the fatigue performance of NTS materials under varying conditions and determine the suitability of modelling techniques to predict fatigue performance across all NTS material types.
Abstract	The proposed project addresses the call topic area of low-carbon energy carrier roles in accelerating decarbonisaton pathways by characterising the condition of legacy gas (methane) pipeline steels after service exposure. Existing hydrogen embrittlement relationships do not properly consider the effect of steel pedigree on degradation. This research will use the results of detailed characterisation to fully document steel microstructure and rigorously track hydrogen interaction with specific features. The results will be directly relevant to assessing the suitability of the current network for hydrogen gas transport. Moreover, the learnings will inform the design and manufacture of future systems. Support involving the supply of suitable legacy specimens has been obtained from National Grid and EPRI will provide review and input on methods used and aid dissemination of findings.
Publications	(none)
Final Report	(none)
Added to Database	14/10/22