CDT Conference Poster Booklet 2017

44 Pages·2017·9.82 MB·English

6th ANNUAL CONFERENCE OF THE
CDT IN ADVANCED COMPOSITES FOR INNOVATION AND SCIENCE

POSTER BOOKLET

Tuesday 11th April 2017
University of Bristol, Queen’s Building, University Walk,
Bristol, BS8 1TR, UK
Multifunctional
Composites and Novel
Microstructures
Patient specific hip implants
Behjat Ansari, Kate Robson Brown*, Richard Trask+, Mark Schenk, Nic Roberts
*Department of Archaeology and Anthropology (University of Bristol), +Department of Mechanical Engineering (University of Bath)
The feasibility of a bespoke revision hip implant solution is evaluated through the
characterisation of the trabecular architecture of the acetabulum, the finite element
analysis of a human innominate bone under typical load cases and the identification of a
suitable substitute material, together with an appropriate processing method.
Incentives Objectives
Prevent 1.4 million More than Mesh

F Bespoke osteolysis and procedures doubled in CT Scans generation
O L
solution promote A annually – 2000- and FEA
TY osseointegration CI $5.84 billion 2010
I N
UALFE High NA Growing demand, result of rise Structural Implant
QLI durability FI in population age and obesity optimisation manufacture
Trabecular characterisation
Methodology
• CT scanning of 4 hip bone specimens – focusing on acetabular region
• 2D and 3D analyses of histomorphometric parameters
70 120
mes 60 of 100
CddlfcperoeiaTossmmc smcsk opocre nataandhtmnrs ieenn tio rdfueaaif eot cttwdtuioenh os tgetaa rh a pbkfaenep u) cdmel mul toasrmaosraplaree baenre er scdsdtcpeogeue e e lnataac hsweinmee ad lwyey ni t h 3D ANALYSIS% Bone volume for 3 voluof interest B.V/T.V (%)Fe12345m000000ale M11111111111ale Male - 2222222222222LEFT Male -333333333333 RIGHT 2D ANALYSIS% Bone area for 6 regions interest B.Ar/T.Ar(%) -22468000000 1 21210 3 11304 10550 6
edge, highlighted in e), b) thick
cortical bone bordering the Notable findings
cancellous region, c) smaller
• Bone volume on average 14% lower in female specimen
trabeculae, transversely
connecting the larger, longitudinal • Varying degrees of anisotropy – variations in loading direction
counterparts visible in d).
Finite element analysis
m Methodology
u
m
xi • Loading for one-
a
m legged stance
of s
Contour plots principal stres • Pjjsooyiniimnnnttpes ahd –n yadssti as pt cuwrbooiicli ac Fjorienet bfoordcye sd,i awghrearme Kof ish ip
Notable findings body weight minus weight
of bearing leg, M is
• Max principal stress 1.373 GPa at sacroiliac joint abductor muscle force and
R is joint reaction force,
• Compressive stress of 12 - 30 MPa around acetabulum edge – increasing with a and b moment
tensile stress away from the edge arms of the forces K and M
from the hip joint, Byrne
• Varying body weight, abductor muscles force, joint reaction force and lever et al. (2010).
arm ratio contribute to variations in load magnitude and stress distributions
Future work
Explore additive manufacturing methods such as FDM and EBM to create porous hydroxyapatite and
tantalum scaffolds, and develop structural optimisation methods to aid implant design.
Supported by
www.bristol.ac.uk/composites
Positioning and aligning CNTs by external
magnetic field to assist localised epoxy cure
Giampaolo Ariu, Ian Hamerton, Bhrami Jegatheeswaram Pillai,
Dmitry Ivanov
The investigation of effective through service on-platform repair technologies for
propulsion systems is of interest for aerospace applications. The research focuses
on the manipulation of nanofillers such as multi-walled carbon nanotubes
(MWCNTs) through external magnetic fields for advanced curing.
Methodology
• Magnetic CNT positioning to create tailored
CNT networks within composite.
• Localised heating from CNTs for more
controlled curing process.
Schematic of composite inner structure for CNT magnetic alignment and translation.
Magnetic positioning of the plated MWCNTs within epoxy resin
Nickel-plated Magnetically
CNTs blended driven CNT edge
s
ess with epoxy resin ng pCaNtTte mrna ncoipnufilramtioend
c and exposed to di
o n within resin.
10 mm Pr through-thickness Fi Alternative metals
DC magnetic field
tested showing
Left: Ni-plated CNT positioning within epoxy PRIMETM20LV after exposition to B = 0.5 T until resin cobalt (Co) as
(top view). Right: computerised tomography (CT) scan of PRIMETM 20LV + 2.5 wt.%
Ni-plated MWCNTs (in red) under 0.5 T [1]. gelation. best plating.
Magnetic positioning of Co-plated CNTs within composite: procedure
Sample preparation
NCF glass printed with 2.5 wt.% Co-plated
CNT-filled epoxy (field/no field exposition),
followed by resin infusion.
A
Sample characterisation B
(c) C
Co-CNT magnetic migration (A -> B -> C)
from fracture surfaces through Co mapping
(b)
via SEM/EDX, together with mDSC/FT-IR
(a)
for Co-CNT effect on cure degree ((cid:302)).
(a) Resin printer head used for the magnetic patch printing; (b) magnetic patch highlighting
sample region and characterised fracture surfaces A, B, C; (c) machined sample region (c).
Magnetic positioning of Co-plated CNTs within composite: results
Cobalt distribution progression
(magnetically driven CNT migration + filtration):
Co-plated CNTs could localise and assist cure
Increasing (cid:302)
A B C
Energy-dispersive X-ray (EDX) cobalt mapping (Co represented by yellow regions) at the fracture surface from Modulated Differential Scanning Calorimetry (mDSC) results showing effect
location A to C. of Co-CNT distribution on cure kinetics.
Future work [1] Ariu G., HamertonI., Ivanov D., Open Physics. (2016) 14:508-516 (DOI 10.1515/phys-2016-0057).
Inductive cure of scarf
Supported by
samples bonded with Co-CNT-
filled adhesive, followed by
www.bristol.ac.uk/composites
bond strength tensile testing.
UV-responsive liquid crystal elastomers for
room temperature shape change
Laura Beckett, George Whittell, Valeska Ting, Richard Trask, Annela
Seddon and Ian Manners
Liquid crystal elastomers (LCEs) are capable of programmed shape change by
switching between the nematic mesophase and the fully disordered isotropic state.
By introducing a UV-responsive azo group to the mesogen, disruption of the
nematic phase can occur reversibly at room temperature; a process which has
been exploited for soft actuators. This work focuses on developing thermoplastic
LCEs with the aim of using extrusion to obtain well-aligned, UV-responsive fibres.
Polymer Synthesis and Characterisation
A synthetic route to the DSC confirms thermal
functional polymer has been xSiOySiOzSiOSizOSiy x transitions in desired range:
developed with the following O OS OS S + N OO OC4H9
advantages: OH OH OH H9C4O NHO =LC W/g) -0.1 PTgM–VS2 0M°idCblock TNiesom–a1tic2-0Is°oCtropic
• High yield – 85%. DichlorDoCmCethane Room48tehmopuerrsature ow ( -0.2 transition
DMAP Fl
• Mild reaction conditions. eat
H -0.3
• Ability to accommodate a SiOSiOSiOSiOSi
x y z z y x -0.4
variety of polymer S S S -50 0 50 100 150
Temperature (°C)
bgraocukpbso.nes/mesogenic LOCO OO OOLC tAebmopvee rtahtiusr eT g–at room Troraonms ittieomn poecrcautursre a t
N O polymer is soft and with UV irradiation
H9C4O N OC4H9 deformable
O
UV-Induced Shape Change Towards Responsive Fibres
• Stretching polymer film in isotropic • Aim to use shear forces encountered
state aligns mesogens to enable during extrusion to form a well-aligned
shape change. liquid crystal monodomain.
• Manually stretched thin film held
Isotropic polymer in
under tension (25.7 kPa stress) -
contracts on irradiation with UV light:
Anisotropic, responsive
fibre out
0.020n n n
O O O
V- V- V-
UV-On Force (Newtons) 000...000011505U UV-O U UV-O U UV-O Fmloewso tghernosugash fsocrrceewd etxhtrrouudgehr naolizgznlse
Polymer Film 0.000 ff ff ff
• Compare UV response with manually
0 60 120 180 240 300 360 420
UV-Off Time (seconds) aligned film.
• Visible light returns polymer to its
• Investigate effect of fibre diameter on
original state – contraction stops.
response.
Supported by
www.bristol.ac.uk/composites
Inverse opals for active colour tuning devices
Diego Bracho, Ian Hamerton, Richard Trask, Annela Seddon
Photonic crystals are periodic ordered microstructures, built from dielectric
materials, with a periodicity in the scale of visible light wavelength (~200-700
nm). Through rational design and smart tuning of the PC periodicity it is possible
to tailor the colour exhibited by these materials. The main objective of this work is
to design and assemble photonic crystal structures based on colloidal self
assembly and silica sol-gel chemistry for active colour display devices.
Results (a)
Polymer opals and silica inverse opals were
prepared by colloidal self-assembly and sol-
gel chemistry. The resulting species exhibit
angle-dependant colouration characteristic of
555mm
photonic structures (Fig. 1a). These exhibit a
(b) (c)
face-centered cubic (FCC) structure, with the
(111) plane oriented at the surface of the
structure (Fig. 1b,c).
The exhibited colour can be tuned by altering
22(cid:645)(cid:645)(cid:645)(cid:645)m 22(cid:645)(cid:645)(cid:645)(cid:645)(cid:645)(cid:645)(cid:645)(cid:645)m
one or more physical parameters of the
Figure1:
system, such as lattice spacing (Fig. 2), a)PhotographofSiO inverseopalcoatedwithsilver((cid:660)=1μm)
2
symmetry, induction of defects, and refractive b)SEMimageofapolymerdirectopal((cid:660)=240nm)
index contrast (Fig. 3). c)SEMimageofSiO inverseopal((cid:660)=500nm)
2
1000 nm
500 nm
310 nm
240 nm
Glass
substrate
Figure3:DiffuseUV-visspectraofSiO inverseopals((cid:660)=240nm)
Figure 2: Diffuse UV-vis spectra of PS opals ((cid:660)=240, 2
coatedwith15nmAginair(a),andinfilledwithethanol(b).Inset
310,500and1000nm)
showsphotographsofthedevicedisplayingcolourchange
Conclusions and Future Work
• Direct and inverse opals of different pore sizes were fabricated using a vertical deposition
method in a single-step co-assembly of polystyrene colloids in a silica precursor solution.
• Tunability of the photonic bandgap within the visible spectrum is interesting for potential
applications in photonics and optics, such as colour display devices, active camouflage,
sensors, etc. Future work will include the integration of smart materials, aiming for
complete tunability within the visible spectrum.
Supported by
www.bristol.ac.uk/composites
Surface modification of composite material for
space application—a baseline
Yanjun He, Ian Hamerton, Mark Schenk, and Alex Brinkmeyer
To improve the durability of composites materials for space applications, a surface
modification ‘Photosil’ technique is considered. This technique is a surface modification
treatment which improves the resistance to atomic oxygen and UV radiation by
silylation of the surface of the composite material. For space deployable structures,
where flexural properties are of great importance, tests are performed to ensure the
modification does not affect the flexural properties of the material. In this work, a
three-point bend and bend radius test, together with acoustic energy measurements,
were performed on four types of untreated samples. Together these form a baseline
for subsequent comparison to Photosil-treated samples.
Test methods
• A three point bend according to ASTM D790-15 is applied to the
samples. After the first test, the samples are bent around a rigid
cylinder 10 times to simulate repeated stowage damage. An acoustic
sensor is used to record the energy during the bends to detect fibre
damage and failure. The three-point bend test is conducted again after
simulated stowage.
• Laminates tested (all laminates contain toughened epoxy):
- LAM01: Carbon PW 94gsm -LAM02: Carbon PW 61gsm
- LAM03: Kevlar PW 60gsm - LAM04: Hybrid Kevlar 60gsm/Carbon 61 gsm Bend radius test set-up
Results
Acoustic Energy (AE) and amplitude vs. bend number for
Flexural stiffness before and after bend for
(a) LAM01, (b) LAM01 (rescaled), (c) LAM02, (d) LAM03 and
each sample
(e) LAM04
Conclusions and future work
• Fibre failure occurred the first bend of LAM01, meaning that this laminate is not suitable for this
stowage application. LAM01 and LAM03 show more matrix cracking signs compared to LAM02 and
LAM04, with the Kevlar laminate undergoing significant damage after 10 cycles of stowage.
• The results from the acoustic sensor showed consistent results with three-point bend.
• Future work consists of optimising the set-up of bend radius test to improve the baseline, and of testing
samples after Photosil treatment and VUV/ATOX exposure.
Supported by
www.bristol.ac.uk/composites
Creating folds: Origami inspired morphing
Manu Mulakkal, Richard Trask, George Whittell, Ian Manners and
Annela Seddon
Folding is a key process at the heart of morphing or transformations that occur in nature.
Whether it’s the formation of proteins from polypeptide sequences or vast mountain ranges
through the movement of tectonic plates; folding is ubiquitous in nature. A methodology for
creating folds on fibrous substrates, such as paper, utilising the forces developed within
hydrogels during drying is presented. This methodology is not just limited to folds but curves
and sophisticated pop-up structures can also be realised through pertinent design. The
shapes formed can revert back to the flat configuration using the stimuli of water. This
methodology and design parameters are envisaged to better inform the design and
fabrication of stimuli-responsive fibrous substrates.
Principle of actuation: shrinking driven
Shrinking of hydrogel due to loss of water would create a positive curve on paper due to
strain mismatch driving the open regions close to each other
Independent Coupled
free ends
Hydrogel Paper De-hydrated gel
5 mm 10 mm 15 mm
180 °C for 5 min
Flat
Pop-up
30mm 30mm
The resulting fold angle depends on: the amount of gel-forming polymer, its spread,
stiffness of paper (i.e grammage) and open area that needs to be folded
Examples of some Origami inspired transformations
Rectangle to helix Concentric circles to saddle-like shape
Hydrogel lines at prescribed angle and spacing on paper Scale bar: 25 mm
Construction
45°:(spacing 10 mm) 45°(10 mm) 30°(5 mm) 45°(5 mm) 1-annular paper cut (bottom)
2-gel
1 2 3 1 3-annular paper cut(top)
30°: (spacing 5mm) Front view Side view
3
1 1
45°:(spacing 5 mm)
Scale bar: 10 mm
Supported by
www.bristol.ac.uk/composites
Additive manufaFclowt/fiultratrioning of multi-functional and
patterned GFRP composites
Arjun Radhakrishnan+, David Stanier+, Ian Gent+, Ian Hamerton+,
Milo Shaffer*, Dmitry S Ivanov+
+University of Bristol, *Imperial College London
Conventional liquid composite moulding processes are hindered by high viscosity when using
multiwall carbon nanotubes (MWCNT) enhanced resin. To overcome these limitations and
allow the processing of patterned multi-functional GFRP, a combination of two novel
approaches are explored in this work : a) use of heterogeneous solution (powder-
liquid) and b) Liquid resin print. This process allows for localised enhancement of
mechanical and functional properties of the composites.
PROCESSING OF PATTERNED COMPOSITES PATCH MORPHOLOGY
Step 1: Heterogeneous solution • Filtering of the powder through the fabric from the
site of the injection leads to natural grading of the
The novel powder
mmaattrriixxppaattcchh..
helps improve the
processability of
solution with higher
CNT loadings by
Solution = encapsulating them
15 wt.% CNT powder + liquid epoxy within solid epoxy.
• Distribution of the particles can be controlled via
processparameters.
• Electrical conductivity maps across the matrix patch
Step 2: Liquid resin printing
varies withconsolidation schemes.
• The solution is injected
into a preform using a • Different patch
3D printer with morphologies are
modified head to form achievable
a matrixpatch. through
consolidation
• Higher loadings of parameters.
upto 3.5 wt% CNTs
are possible when
matrix is applied MECHANICAL PROPERTIES
locally.
• Open hole SSttrreessss,, MMPPaa
tensile test
increase of
Stepp 3: Consolidation (hot press) 17% and 24%
of strain-to-
• Consolidation pressure is failure and
applied at a predefined strength Strain, %
degreeof cure. respectively.
• Patch morphology is
controlled by injection and MOVING FORWARD
consolidation parameters.
• Mechanical modelling of multi-matrix
composites.
• Investigating:
a. Influence of the multi-matrix interface
Step 4: Resin infusion of patched preform
on tailoring the mechanical
performance.
Preform with functionalised
b. Optimisation of patch architecture.
cured patch is infused using
• Assess the feasibility for application in:
conventional processes to
a. Reinforcing stress concentration
create a patterned multi-
features like joints.
matrix composite.
b. Vibrational damping.
Supported by
www.bristol.ac.uk/composites
3D mesostructures via compressive buckling
and potential applications
Rujie Sun, Xinge Yu, Xin Ning, Jonathan Rossiter, Fabrizio Scarpa
Mechanical assembly of 3d mesostructures with programmed configurations are
explored. This method could transfer a variety of advanced materials from 2d
precursors into mechanically tunable 3d architectures with broad geometric
diversity. Such structures show great potential in areas, including microscale
rheology measurement, soft robotics, energy harvesting, and cell mechanics.
Experimental Demonstrations
(cid:41)(cid:76)(cid:74)(cid:17)(cid:3)(cid:20)(cid:17)(cid:3)(cid:57)(cid:68)(cid:85)(cid:76)(cid:82)(cid:88)(cid:86)(cid:3)(cid:22)(cid:71)(cid:3)(cid:80)(cid:72)(cid:86)(cid:82)(cid:86)(cid:87)(cid:85)(cid:88)(cid:70)(cid:87)(cid:88)(cid:85)(cid:72)(cid:86)(cid:15)(cid:3)(cid:86)(cid:70)(cid:68)(cid:79)(cid:72)(cid:3)(cid:69)(cid:68)(cid:85)(cid:3)(cid:24)(cid:19)(cid:19)(cid:3)(cid:459)(cid:80)
Potential Applications
Bonding site
SU8
Actuation
Fig. 2. Soft robotics Fig. 3. Microscale rheology measurement
Supported by
www.bristol.ac.uk/composites