Numerical Investigation and Uncertainty Quantification of Composite Flexible Risers

About the Project

Pipelines, traditionally constructed from steel, form the backbone of the oil and gas industry, facilitating crucial transportation in both onshore and offshore operations. Recent advancements in manufacturability and the distinctive properties of composites, notably carbon fibre composites, have propelled them into the spotlight as a compelling alternative. Offshore pipes are primarily classified into two types; risers and generic tubulars. While all offshore components face challenges, risers, subjected to the most extreme conditions, have become the focal point for the quest for improved solutions.

Offshore risers are required to withstand a multitude of combinations of functional, environmental and accidental loads. These challenges include excessive twist and compressive forces encountered during installation, operation, and recovery, along with potential interference or clashing between the riser and the vessel hull, adjacent risers, and mooring lines. Additionally, there is exposure to thermal stresses, thermal cycling, and the risk of fatigue failure induced by the dynamic action of waves and currents. On the other hand, the susceptibility of steel pipes to corrosion necessitates frequent inspections and repairs, leading to regular shutdowns. This challenge is further compounded by the industry’s shift to deeper waters, requiring longer pipes and imposing substantial loads on the platforms due to the use of steel. Hence, flexible risers, composed of multiple unbound layers incorporating materials such as carbon fibre or other composites, stand out as a preferred choice among available riser options. This innovative design is particularly favoured for its ability to withstand heavy loads and effectively address the shortcomings associated with traditional steel risers.

The fatigue performance of composite flexible risers (CFR) is a crucial design consideration. The cumulative impact of cyclical stresses induced by waves, currents, vessel motion, thermal cycles, and pulsating fluid flow within the tubes results in fatigue. This fatigue, coupled with the development of interlaminar and intralaminar stresses, raises concerns such as delamination, matrix cracking, and fibre breakage, collectively compromising the overall structural integrity of the pipe. Despite its significance, the behaviour of CFR under these conditions has been rarely studied. The responses to fatigue in CFR depend on various factors, including manufacturing technology, environmental conditions, composite architecture, and geometry. Consequently, existing uncertainties in these sources contribute to variations in fatigue responses. A comprehensive understanding and quantification of these uncertainties will facilitate optimal designs, considering that current safety factors are high due to an incomplete grasp of this aspect. Therefore, prediction and uncertainty quantification of the fatigue performance of CFR emerge as a promising research avenue.

Entry requirements

Students with a First class/2.1 degree in Materials Science, Physics, Mathematics or an aligned Engineering subject are encouraged to apply. An MSc in a related filed would also be acceptable. Experience in MATLAB, ABACUS, COMSOL, C++ or any other programming languages and modelling would also be preferable. Also, an MSc and/or publications in a relevant field should also be useful.

Funding

This is a 3.5-year PhD project is open to self-funded students but there are also funding opportunities available. Please feel free to discuss these with the supervisor.

At The University of Manchester, we offer a range of scholarships, studentships and awards at university, faculty and department level, to support both UK and overseas postgraduate researchers.

For more information, visit our funding page or search our funding database for specific scholarships, studentships and awards you may be eligible for.

We recommend that you apply early as the advert may be removed if the position is filled.

The start date for funded students is October 2026. The start date for self funded students is negotiable.

Before you apply

We strongly recommend that you contact the main supervisor for this project (Dr Abeykoon - chamil.abeykoon@manchester.ac.uk) before you apply. Please include details of your current level of study, academic background and any relevant experience and include a paragraph about your motivation to study this PhD project.

How to apply

You will need to submit an online application through our website here: https://uom.link/pgr-apply

When you apply, you will be asked to upload the following supporting documents:

• Final Transcript and certificates of all awarded university level qualifications
• Interim Transcript of any university level qualifications in progress
• CV
• You will be asked to supply contact details for two referees on the application form (please make sure that the contact email you provide is an official university/ work email address as we may need to verify the reference)
• Supporting statement: A one or two page statement outlining your motivation to pursue postgraduate research and why you want to undertake postgraduate research at Manchester, any relevant research or work experience, the key findings of your previous research experience, and techniques and skills you’ve developed. (This is mandatory for all applicants and the application will be put on hold without it.
• English Language certificate (if applicable). If you require an English qualification to study in the UK, you can apply now and send this in at a later date.

If you have any queries regarding making an application please contact our admissions team FSE.doctoralacademy.admissions@manchester.ac.uk