Quickfire Presentations

2-minute-2-slide

Second and third year CDT

students

Running Order

Structures• A one-dimensional snap-through model of the aeroelastic tymbal sound

production in Yponomeutidae moths - Hernaldo Mendoza Nava

Materials• Thermally reversible epoxies: self-healing, reshaping and recycling. - Callum Branfoot• Active thermal management via embedded vascular networks - Jim Cole• High voltage switching of dielectric elastomer actuators using thin film amorphous

Silicon - Calum Gillespie• Machine-Driven Experimentation For Solving Challenging Consolidation Problems -

Antoly Koptelov• Understanding of Leading-Edge Protection Performance Using Nano-Silicates for

Modification - Imad Ouachan• Nanodiamond composites: comparing manufacturing methods on material properties

- Dominic Palubiski

1D sound production

model of the Ermine Moth

Hernaldo Mendoza Nava

Rainer Groh, Marc Holderied (School of

Biological Sciences), Alberto Pirrera

CDT Conference 2019

16th April, 2019

Buckling as a defense mechanism4

16th April, 2019

1-D sound production model of the Ermine Moth

Hernaldo Mendoza Nava

Ermine moths produce bursts

of clicks to defend against

bats.

The sound originates at a

clear patch in its wings

(aeroelastic tymbal).[1][1]

[1] O’Reilly, 2019. Scientific Reports (9:1444)

Tymbal sound production5

16th April, 2019

1-D sound production model of the Ermine Moth

Hernaldo Mendoza Nava

1.

Static Riks Analysis – Determine

structural instabilities

2.

Modal & SSD – Rayleigh damping

parameters computation

Explicit Dynamics – Structural response

due to cyclic loading

3.

FFT analysis & Baffled-Piston model –

Calculates the sound pressure level and

directionality

Spectrogram – Representation of the on

axis emitted sound

o A 1D model allowed to

reproduce a single click

o Low frequency spectra

suggests a pre-stressed

structure

Future workFE analysis of a 2D shell model

1D model

U, magnitude

CANs: from dynamic

bonds to functional

compositesCallum Branfoot, Hartmut Fischer, Tim

Coope, Duncan Wass, Paul Pringle and Ian

Bond

CDT conference 2019

16/04/19

Covalent adaptable networks, CANs7

callum.branfoot@bristol.ac.uk / 16/04/19

Callum Branfoot / CANs

MotivationPoor recyclability,

repairability and

toughness of

conventional FRPs

CANsReversibly crosslinked

polymers based on

dynamic chemistry

Thermoset >> Thermoplastic >> Thermoset

Epoxy CANs for composites8

Healin

g

Recyclin

g

callum.branfoot@bristol.ac.uk / 16/04/19

Callum Branfoot / CANs

Active Thermal

Management via Embedded

Vascular Networks

Jim Cole, Ian Bond, Andrew Lawrie

CDT Conference

16th April 2019

Problem10

Chowdhury et al, “Mechanical Characterization of Fibre

Reinforced Polymers Materials at High Temperature”, Fire

Technol, 47, 1063-1080, 2011

• Polymer matrix limits operating temperature due to glass transition temperature, Tg

• Significant performance reduction, up to 50% at Tg• Thermo-oxidative ageing over long term

• Tg is typically 100°C to 150°C for aerospace epoxies

• Emerging applications expose composites to higher temperatures:

• Turbo-machinery

• Battery containment

• Hypersonic aircraft

Solution11

• Circulate fluid through small passages (vascules) inside the laminate

• Maintain matrix below Tg to retain performance, extend service life

• 4-vascule arrays embedded in QI CFRP samples using PTFE-coated wire

• Custom thermal chamber and test fixture required due to high temperatures

• Tested in four-point flexure up to 170°C (Tg=200°C)

• Initial results indicate a flexural strength reduction of -25% without cooling, and -6% with cooling flow

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

23°Cpristine

23°C0.00 bar

121°Cpristine

170°Cpristine

170°C0.00 bar

170°C1.00 bar

Ultimate flexural strength results

Thermal chamber

surrounding four-point bend

fixture

Embedding PTFE-coated

wires into layup

Acknowledgements12

The authors would like to acknowledge Rolls-Royce plc for their support of this research through the Composites University Technology Centre at the University of Bristol, UK.

High-voltage Photonic

Switching with Amorphous

Silicon Thin-film Composites

Calum Gillespie, Andrew Conn,

Johnathan Rossiter, Fabrizio

Scarpa, Asier Marzo.

CDT Conference 2019

16.4.19

High-voltage Photonic Switching with Amorphous Silicon Thin-Films Composites.

14

16.4.19

Calum Gillespie

Andrew Conn, Johnathan Rossiter, Fabrizio Scarpa, Asier Marzo.

Light on Light onLight off Light offLight off

Light off Light on Light off Light on Light off

1. Inspiration

2.

Current work

SPIE EAPAD XXI: Paper number - 10966-55

High-voltage Photonic Switching with Amorphous Silicon Thin-Films Composites.

15

16.4.19

Calum Gillespie

Andrew Conn, Johnathan Rossiter, Fabrizio Scarpa, Asier Marzo.

Reproduced from: Majid Taghacvi, Tim Helps

and Jonathan Rossiter, Electro-ribbon

actuators and electro-origami robots. Science

Robotics 2018.

3. Future applications – Alterative actuation:

• Electro-active Ribbon Actuators

Amorphous Silicon Poly-imide Composite

0 Seconds 1 Second 2 Seconds 5 Seconds

0k

V6k

V

6k

V0k

V

Machine-driven

experimentation for solving

challenging consolidation

problems

EPSRC ACCIS CDT Conference 2019

A. Koptelov, J.P.-H. Belnoue,

I. Georgilas, S.R. Hallett, D. S. Ivanov.

Supported by the EPSRC Platform Grant, Science and

SIMulation of new manufacturing PROcesses for

Composite Structures (SIMPROCS)

Consolidation and Characterisation testing strategies

17

Examples of different flow modes in the

specimen. [1] Belnoue et al.No universal testing procedure for

compaction of composite precursors

Toughened prepregs

[1] Belnoue et al.

Low viscosity UD prepregs

[2] Hubert et al.

Project scheme18

Processing Framework

Hardware

Consolidation sensor

Forc

e

Input load schedule, subject to definition

Time

Possibleload

Chosenload

Thickness (time)

Consolidation sensor is capable of recognizing the flow/deformation modes by its

characteristic signatures

Measurement and Understanding

of Viscoelastic Wind Blade Erosion

Coatings

Imad Ouachan, Kirsten Dyer (OREC),

Ian Hamerton and Carwyn Ward.

8th Annual CDT Conference

Tuesday 16th April 2019

Leading Edge Erosion 20

ACCIS CDT Conference 16/04/2019

Imad Ouachan - Measurement and Understanding of

Viscoelastic Wind Blade Erosion Coatings

• Rain impact velocities of >100 m/s

• Emergency repair of several modern wind farms e.g. London Array

(140 out of 175 turbines)

• Costs the European offshore wind industry between €56m- €75m

annually [4]

• Reduced lifetime

• Decrease in aerodynamic performance (1.5 - 2.5%)

• Reduction in annual energy production from (3 - 5 %)

• Inspection and repair programmes

• Tip speeds limited to ~100 m/s

[3] Five reasons for protecting the leading edge with Belzona,

https://blog.belzona.com/5-reasons-leading-edge-belzona/

[4] Wiser RH et al. Forecasting Wind Energy Costs and Cost Drivers.

DOI: 10.1016/S0379-6779(99)00311-2.

Results

ACCIS CDT Conference 16/04/2019

Imad Ouachan - Measurement and Understanding of

Viscoelastic Wind Blade Erosion Coatings

21

20 40 60 80 100 120 140 160

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Tg = 85 °C

Tan

Del

ta

Temperature (°C)

Neat Filler

Neat LEP

LEP + 10 wt.% NanoTg = 54 °C

1) Dynamic Thermal Analysis

Unmodified Nano Modified

2) Accelerated Rain Erosion Testing

Nanosilicate Modification

Nanodiamond composites;

comparing detonation and

high-pressure/high-

temperature nanodiamonds

within epoxy matrices

D. R. Palubiski, N. Fox, F. Scarpa

ACCIS CDT Conference 2019

Wednesday, 17 April 2019

Nanodiamonds in Resin23

Detonation Nanodiamond

17 April 2019

D. R. Palubiski

High-Pressure/High-Temperature Nanodiamond

Nanodiamond in Resin24

17 April 2019

D. R. Palubiski

Experimental Testing of Samples

TEM Images of HPHT in Resin