Final Year Student Projects in

a.mcmillan@glyndwr.ac.ukMini Biography: Alison McMillan studied Maths and Physics BSc at University CollegeLondon and Mechanical Engineering MSc at Cranfield. Her PhD from StaffordshireUniversity involved computational modelling of vibration and impact of laminates.Following a series of post-doctoral positions at the University of Oxford and KeeleUniversity she moved into industry, working almost 15 years at Rolls-Royce plc in Derby,on the interface between new product introduction and capability acquisition.

Between 2007-2011 she held a Royal Society Industry Fellowship, based part-timeat the University of Bristol. Alison left Rolls-Royce plc in October 2011, and is currentlyProfessor in Aerospace Technology at Glyndwr University.

Invitation to collaborate

Please contact me if you are interested in any of the aspects presented here.

Alison McMillan, Dennis Pflugmacher, Martin Duschl, Marc Worch and Ron Schreinecke

Computational MechanicsDennis Pflugmacher: Multiple crack development using XFEMI am investigating multiple crack development using the extended finite element method (XFEM), and have chosenAbaqus since it provides a powerful XFEM framework to model discontinuities like cracks. XFEM allows cracks to

initiate and propagate along an arbitrary pathwithout the need to adjust the meshmanually after each crack growth increment.

The aim of the project is to investigatethe impact of corrosion pits on crackdevelopment. Therefore, corrosion pits arebeing mimicked as missing material, byadding small holes and hemispherical pits intoa simple plate, with increasing applieduni-axial tension to see the behaviour ofnucleating cracks. A simple 2D model was

used to investigate influences ofmultiple pits of random size andposition. Since cracks can onlydevelop in “enrichment zones”these features need to bespecified by the user. Each crackmust be assigned to its ownenrichment zone to enablemultiple crack modelling. Thechallenge is to anticipate thegrowth pattern of each crack,

and create those enrichment zones appropriately.

Although I was totally new to Abaqus I quickly becamefamiliar with it, not at least due to the helpful tutorials.Whenever I was facing difficulties the Abaqus internetcommunity provided me with help.

I do think the experiences I gained in using Abaqusand fracture mechanics have definitely increased mychances in finding a job in a research department.

Manufacturing SimulationMartin Duschl: Numerical simulationof the turning processThe numerical simulation of a turning process is a verymulti-layer and complex task, requiring the considerationof factors such as the behaviour of highly deformedmaterial and the friction forces which arise due tointeraction between chip and work-piece. Furthermore,

process parameters likecutting speed, cutting depth,and the radius and rake angleof the cutting insert influencethe process performance.

To investigate thesefactors a Coupled Eulerian-Lagrangian (CEL) simulation ofconventional orthogonal cutting was performed. The

work-piece is a straightrectangular body and thecutting insert performsthe cutting movement.

An Eulerian grid issuperimposed over thework-piece material andis sized to cover the chip flow which will develop duringthe machining process.

The big advantage of the Coupled Eulerian-Lagrangianformulation is that the Lagrangian material can movethrough the Eulerian mesh wherefore the simulation isfree of element distortion; the CEL formulation iswell-suited for the investigation of problems involving

highly deformed material.The CEL-Simulation is a great way to visualise and to

measure the influence of process parameters on responses suchas the cutting forces, chip morphology and stress distribution.

I worked at a lathe in my apprenticeship,and later I was responsible for the workpreparation of turning processes in seriesproduction.

Now, using Abaqus gave me theopportunity to investigate the turning processin my final year project, which helped me tounderstand it better.

Component AnalysisMarc Worch: Analysis cases foraero-engine radial drive shaftsThe aim of the project is to develop and model aradial drive shaft of an aero-engine. Differentdesign variations of a radial drive shaft wereconstructed and analysed for natural frequencies,stress-strain and the critical buckling load.

Various materials were used andanalysed and the modellingconsidered variousboundary conditions toreplicate the shaftbearings.

Research into the design requirements of a radial drive shaft showed the mostimportant aspects for which analysis must be undertaken and evaluated. Aero engines

require a very high level of quality and safety. Analysis showed that wall thickness is veryimportant, but attention must be paid to the weight of the shaft. The outer diameter of the

shaft is also very important, because space is limited in an aero engine.

Through my studies at Wrexham GlyndwrUniversity, I had the opportunity to learn aboutcomponent analysis using Abaqus. This gave me anew perspective on the effects of many differentcomponent load-cases.

Thanks to Professor Alison McMillan’s support, Ilearned how extensively an engine component isanalysed before it is produced.

To ensure the function of the door seal two main tests are carried out during the production. The first is to measurethe size by checking the cross section of the seal. The second is to measure the deformation force that is needed tocompress the seal. This is done with a test called the load deflection or compression load.

The analysis in my project simulates this compression test and measures the forces which occur during thedeformation. It is important that the seal cross section is optimised such that the sealing force matches the designspecification (15 N). If the force is too low, the pressure would not be sufficient to form a seal between the doorand the car body, and would result in leakage. If the force is too high, the door would not close properly.

It was found that the placing of enrichment zones, the mesh topology,and location of“corrosion pits” have aninfluence on the crackgrowth behaviour.

The XFEM is anelegant way to modellingcracks, but still poseschallenges especially inareas where neighbouring cracks become too close to each other.

Design & OptimisationRon Schreinecke: Design of asealing system for a car.The aim of my project is to develop and design a sealingsystem for a car door. Several sealing systems areinstalled all around the car to protect the driver andpassengers from incoming water. Additionally seals helpto reduce the noises, mainly wind noises, whicharise during driving or are caused by vibration.

Sealing systems, which are installed in amovable or flexible area, are subject to largedeformations during the opening and closingcycles. This means that the materials used forthe seals must have very good properties indeformation and relaxation. In consequence,most of these seals are produced of EPDMrubber (Ethylene-Propylene-Diene-Monomer).

Before I started the project I have had noexperience with the ABAQUS software. Usingthis software helped me to understand howimportant those FEM calculations are. I couldsee directly which effect a small change in theshape had by analysing the deformation andchecking the results.

BEng final year students studying Engineering at Wrexham Glyndwr University undertake a project as part of theirstudies, which represents one third of their final year grade. This project is spread over both semesters, and givesthe students an opportunity to develop particular new skills, and plan and manage their own work. Frequently theprojects are linked with particular research activities within the School of Applied Sciences, Computing andEngineering.

The projects presented here were carried out in conjunction with the Computational Mechanics, ManufacturingSimulation, Design & Optimisation (CoMManDO) Research Group, under the supervision of Alison McMillan.

Science in the Age of ExperienceMay 23-25, 2016 • Boston, MA

Initial design, for which the sealing force (7.1 N)is too low. Observe the gap formed between the

stamp and the seal tube.

Optimised design, with sealingForce 16.2 N. There is now very

little gap formed between thestamp and the seal tube.

Buckling in torsion

Vibration mode