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PhD Opportunities

Advanced manufacturing of aircraft composite structures

School of Mechanical and Aerospace Engineering | PHD
Reference Number
Application Deadline
None specified
Start Date
1 October 2021


The aim of the project is to explore intrinsic mechanisms and relationships between orbital drilling process parameters and geometrical accuracy, mechanical properties as well as surface integrity of holes in aircraft AL/CFRP/Ti stacked composites, the crucial fundamentals leading to realization of optimized machining processes deploying advanced robotic automation. The outcomes of the project will provide the concrete theoretical and technical foundations and bring significant benefits to the development of automated drilling equipment and processes for aircraft assembly.

The increased use of anisotropic CFRP stacked in layered combination with aluminium and titanium in aircraft structures has created enormous challenges for the industry due to the difficulties arising from drilling these heterogeneous materials [1, 2]. The difference in modulus of elasticity and coefficient of thermal expansion of each material, composite or metallic, induces undesirable hole tolerance variations throughout the stacked materials. Other problems encountered during drilling include rapid tool wear, CFRP damage, poor surface finish and burr formation due to the disparity in material properties [3-6].
Currently, these multilayered stacks which include layers of CFRP, titanium and aluminium of variable thicknesses are arranged and then fastened together following a multi-shot machining process which involves a series of drilling, reaming, disassembly, deburring and reassembly operations [7]. Alternatively, drilling through multilayered material stacks in a single-shot process to produce high quality, burrless holes with acceptable tool wear removes the need for multiple operations and manufacturing stages, and reduces cost and cycle times [8]. But this single-shot process requires a high performance automated manufacturing system, which offers high flexibility and high dynamic responses. The orbital drilling is considered as one of the best choices to perform the hole making on stacked AL/CFRP/Ti due to lower cutting forces/temperature and high efficiency. However, the main material damage of such kinds of materials including delamination and burr formation will affect the hole making quality. In addition, the geometric error of hole diameter easy encountered during orbital drilling include the insufficient size of hole diameter, hole diameter at stacked AL/CFRP/Ti exit less than hole diameter at CFRP entrance [9]. Because there are wave texture at the surface layer of CFRP hole and tool runout during orbital drilling, the roundness in orbital drilling of CFRP is large than the roundness in conventional drilling of CFRP [10,11]. Although a number of research efforts have been directed to this research area, most of them are empirical and the machining mechanism and surface integrity are still unclear. Fundamental characteristics of orbital drilling process for AL/CFRP/Ti stacks will clarify the mechanism of surface damage and thus to avoid its completely unacceptable occurrence in drilling or orbital drilling processes.

1. Brinksmeier, E., Janssen, R., Drilling of Multi-layer Composite Materials consisting of Carbon Fiber Reinforced Plastics (CFRP), Titanium and Aluminum Alloys, CIRP Annals, 51(1): 87-90, 2002.
2. Denkena, B., Boehnke, D., Dege, J. H., Helical milling of CFRP-titanium layer compounds, CIRP Journal of manufacturing Science and Technology, 1(2), 64-69,2008.

3. Brinksmeier, E., Fangmann, S., Rentsch, R., Drilling of composites and resulting surface integrity, CIRP Annals-Manufacturing Technology, 60: 57-60, 2011.
4. Cong, W. L., Pei, Z. J., Deines, T. W., Liu, D. F., Treadwell, C., Rotary ultrasonic machining of CFRP/Ti stacks using variable feedrate, Composites Part B: Engineering, 52: 303-310, 2013.
5. Ni, W.Y., Orbital Drilling of Aerospace Materials SAE Aerospace, Heat Treatment 2012,03-12, 2007.
6. Whinnem, E., Lipczynski, G., Drilling Mixed Stack Materials for the BOEING 787. Self, 1: 1855, 2010.

7. Shyha, I.S., Soo, S.L., Aspinwall D.K., et al. Hole quality assessment following drilling of metallic-composite stacks, International Journal of Machine Tools and Manufacture, 51(7-8): 569-578, 2011.

8. Avila, M., Gardner, J., Reich-Weiser, C., et. al., Strategies for burr minimization and cleanability in aerospace and automotive manufacturing, SAE Technical paper, 2005-01-3327, 2005.
9. Zhou L, Ke Y, Dong H, et al. Hole diameter variation and roundness in dry orbital drilling of CFRP/Ti stacks[J]. The International Journal of Advanced Manufacturing Technology, 2016: 1-14.

10. Wang B, Gao H, Bi M, et al. Mechanism of reduction of damage during orbital drilling of C/E composites[J]. Jixie Gongcheng Xuebao(Chinese Journal of Mechanical Engineering), 2012, 48(15): 173-181.
11. Li Z, Liu Q. Surface topography and roughness in hole-making by helical milling[J]. The International Journal of Advanced Manufacturing Technology, 2013, 66(9-12): 1415-1425.

Project Summary
Dr Dan Sun
Mode of Study

Full-time: 3 years

Apply now Register your interest

Mechanical Engineering overview

Doing a PhD in the School of Mechanical and Aerospace Engineering is a highly rewarding experience. You will carry out your research in a friendly and supportive environment, supervised by academics who are leaders in their field, using well-equipped laboratories and research facilities, alongside students from all over the world. We have around 100 students enrolled on a PhD at a time. The School has a vibrant PhD student mentoring programme and a student led Research Culture Committee.

The School’s research is focused around six interconnected research themes: Advanced Manufacturing and Processing, Future Aircraft, Composite Materials and Structures, Simulation Technologies, Clean Energy and Biomaterials and Biomechanics.

PhD opportunities are available in a wide range of subjects aligned to the specific expertise of our PhD supervisors. Many are linked with leading companies and organisations.

Key Facts

Research students are encouraged to play a full and active role in the research activities undertaken within the School. Students attend international conferences and participate in relevant external academic and industrial networks worldwide.

  • The School has strong links with both local and international engineering employers, and has longstanding relationships with companies such as Airbus, Caterpillar, ExxonMobil, Ford, Jaguar Land Rover, Lotus, McLaren F1 and Rolls-Royce.
  • PhD research contributes to major interdisciplinary centres in the University, including:
    •Northern Ireland Advanced Composites and Engineering Centre (NIACE)
    •Polymer Processing Research Centre (PPRC)
    •Northern Ireland Technology Centre (NITC)
  • The School has well equipped laboratories and great research facilities. PhD students share offices alongside postdoctoral staff. The School has Research Culture Committee to enhance the research environment of the School and support PhD students.

Course content

Career Prospects

Employment after the Course
Many of our PhD graduates have moved into academic and research roles in Higher Education while others go on to play leading roles in industry, industry or become entrepreneurs.

People teaching you

Dr Trevor Robinson
Doctoral Programme Director
Mech & Aerospace Engineering

Learning Outcomes

Course structure

You will carry out leading research under the guidance of your supervisory team. A full time student will normally complete in three years (up to a maximum of four), or part time over six years (up to a maximum of eight).

Research will usually be in one of the key, interlinked research themes in the School, and the subtopics they cover, include:-

Advanced Manufacturing and Processing - cost modelling, ergonomics, intelligent control, laser processing, life cycle analysis, material characterisation, mechatronics, parallel kinematic machines, polymer processing, robotics and ultra-precision manufacturing.

Future Aircraft - aero engines, aerodynamics, aeroelasticity, aircraft operations, design and analysis, optimisation and structural testing

Composite Materials and Structures -damage mechanics and crashworthiness, material characterisation, multifunctional composites and nano-enhanced composites

Simulation Technologies - FEA/CFD/EFG/DES/MD, kinematic modelling, meshing, multiscale/Multiphysics, optimisation, simulation intent, systems modelling, uncertainty quantification, virtual testing and design visual analytics and big data

Clean Energy - biofuels, catalysis, life cycle assessment, power systems, turbomachinery and waste management

Biomaterials and Biomechanics - biomimetics, material characterisation, mechanobiology and medical devices.

Also, over the course of study, you can attend postgraduate skills training organised by the Graduate School, or other internal and external training courses organised through your supervisor.

Entrance requirements

The minimum academic requirement for admission to a research degree programme is normally an Upper Second Class Honours degree from a UK or ROI HE provider, or an equivalent qualification acceptable to the University. Further information can be obtained by contacting the School.

International Students

For information on international qualification equivalents, please check the specific information for your country.

English Language Requirements

Evidence of an IELTS* score of 6.0, with not less than 5.5 in any component (*taken within the last 2 years) is required.

International students wishing to apply to Queen's University Belfast (and for whom English is not their first language), must be able to demonstrate their proficiency in English in order to benefit fully from their course of study or research. Non-EEA nationals must also satisfy UK Visas and Immigration (UKVI) immigration requirements for English language for visa purposes.

For more information on English Language requirements for EEA and non-EEA nationals see:

If you need to improve your English language skills before you enter this degree programme, INTO Queen's University Belfast offers a range of English language courses. These intensive and flexible courses are designed to improve your English ability for admission to this degree.

As a result of the COVID-19 pandemic, we will be offering Academic English and Pre-sessional courses online only from June to September 2020.

  • Academic English: an intensive English language and study skills course for successful university study at degree level
  • Pre-sessional English: a short intensive academic English course for students starting a degree programme at Queen's University Belfast and who need to improve their English.

Tuition Fees

Northern Ireland (NI) 1 £4,500
Republic of Ireland (ROI) 2 £4,500
England, Scotland or Wales (GB) 1 £4,500
EU Other 3 £22,000
International £22,000

1 EU citizens in the EU Settlement Scheme, with settled or pre-settled status, are expected to be charged the NI or GB tuition fee based on where they are ordinarily resident, however this is provisional and subject to the publication of the Northern Ireland Assembly Student Fees Regulations. Students who are ROI nationals resident in GB are expected to be charged the GB fee, however this is provisional and subject to the publication of the Northern Ireland Assembly student fees Regulations.

2 It is expected that EU students who are ROI nationals resident in ROI will be eligible for NI tuition fees, in line with the Common Travel Agreement arrangements. The tuition fee set out above is provisional and subject to the publication of the Northern Ireland Assembly student fees Regulations.

3 EU Other students (excludes Republic of Ireland nationals living in GB, NI or ROI) are charged tuition fees in line with international fees.

All tuition fees quoted are for the academic year 2021-22, and relate to a single year of study unless stated otherwise. Tuition fees will be subject to an annual inflationary increase, unless explicitly stated otherwise.

For further information please refer to

More information on postgraduate tuition fees.

Mechanical Engineering costs

There are no specific additional course costs associated with this programme.

Additional course costs

All Students

Depending on the programme of study, there may also be other extra costs which are not covered by tuition fees, which students will need to consider when planning their studies . Students can borrow books and access online learning resources from any Queen's library. If students wish to purchase recommended texts, rather than borrow them from the University Library, prices per text can range from £30 to £100. Students should also budget between £30 to £100 per year for photocopying, memory sticks and printing charges. Students may wish to consider purchasing an electronic device; costs will vary depending on the specification of the model chosen. There are also additional charges for graduation ceremonies, and library fines. In undertaking a research project students may incur costs associated with transport and/or materials, and there will also be additional costs for printing and binding the thesis. There may also be individually tailored research project expenses and students should consult directly with the School for further information.

How do I fund my study?
1.PhD Opportunities

Find PhD opportunities and funded studentships by subject area.

2.Funded Doctoral Training Programmes

We offer numerous opportunities for funded doctoral study in a world-class research environment. Our centres and partnerships, aim to seek out and nurture outstanding postgraduate research students, and provide targeted training and skills development.

3.PhD loans

The Government offers doctoral loans of up to £26,445 for PhDs and equivalent postgraduate research programmes for English- or Welsh-resident UK and EU students, £10,000 for students in Scotland and up to £5,500 for Northern Ireland students.

4.International Scholarships

Information on Postgraduate Research scholarships for international students.

Funding and Scholarships

The Funding & Scholarship Finder helps prospective and current students find funding to help cover costs towards a whole range of study related expenses.

How to Apply

Apply using our online Postgraduate Applications Portal and follow the step-by-step instructions on how to apply.

Find a supervisor

If you're interested in a particular project, we suggest you contact the relevant academic before you apply, to introduce yourself and ask questions.

To find a potential supervisor aligned with your area of interest, or if you are unsure of who to contact, look through the staff profiles linked here.

You might be asked to provide a short outline of your proposal to help us identify potential supervisors.