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Quickfire PresentationsBristol Composites Institute / NCC Joint Conference
21st November 2019
Objective Hygro-thermal models Validation Application
• Hydrothermal dependant strength
𝜎 𝑇,𝑀 , 𝑡 = 𝑓(𝑇, 𝑇 𝑇⁄ , �̇�)
• Interface energy
• Similarly, moduli and in-plane shear models have been developed
• To numerically predict the effect of temperature and moisture on the mechanical degradation of composites
• To develop hygrothermal-dependant bulk matrix and interface property models
SBS- unidirectional [0]34
Transverse Tension [90]11 Cut-ply[(+45/90/-45/0)4 (0)]s
90/-45 interface
90/-45 interface
Room Temperature DRY
Room Temperature WET
Numerical modelling of the hygro-thermal effects of temperature and moisture on compositesGanapathi Ammasai Sengodan
Fibre KinkingFibre Failure Matrix Cracking
Numerical Characterisation Unit Cell ModelEla
stic
Ten
sor
Est
imati
on
Dam
ag
e B
eh
avio
ur
𝜎
𝜀𝜀𝜀
𝜎
0
Damage LawFailure Modes
𝐺 = 𝐹(𝐴 )
Material ModelVoxelisationKinematic model
Initial cracks on the matrix pockets
damage
Transverse matrix cracks and shear induced damage
Strain [%]
yxShear angle, 𝜃
A numerical study of the effect of draping on the mechanical properties of 3D woven compositesIoannis Topalidis
Micro-scale Analysis of CMCs
Micro-scale Analysis of CMCsRiccardo Manno
• Tool for the creation of CMCs microstructures and homogenisation of the physical properties:
Elastic
Thermal
Electrical
• User-Subroutines for interphase pull/push out behaviour and for matrix cracking:
Experiments Performed by R.M.G. De MeyereUniversity of Oxford
Push-out behaviourCohesive + Friction lawPush-out behaviourCohesive + Friction law
Damage InitiationChristensen Criterion
Damage ProgressionSmeared Crack Formulation
Damage ProgressionSmeared Crack Formulation
Surrogate Modelling of Camber-Morphing Rotor Blades
Surrogate Modelling of Camber-Morphing Rotor BladesStephane Fournier
DISCRETE CONTROL SURFACE CAMBER-MORPHING AEROFOIL
FishBAC concept
max ΔCL > 1 max ΔCM > 0.2
Mach 0.6
Skin Sample preparation & Materials Speckle pattern for Digital Image Correlation
Analytical model for granular jamming beamsDavid Brigido
Full-field of transversal strains
WrapToR truss beams
SAMPE “Design and Make” 2019@EPSRC Future CompositesManufacturing Research Hub open day.With Dr Yian Zhao and Chris Hunt.
Christopher J.Hunt et al. 2019
3 points bending test
WrapToR truss beamsFrancescogiuseppe Morabito
WrapToR truss beamsFrancescogiuseppe Morabito
Pseudo-ductility in compression of thin-ply angle-ply laminatesXun Wu
Key challenge: to investigate gradual compressive failure of pseudo-ductile thin-ply angle-ply [±θn/0m]s laminates, via an indirect loading approaches.
Carbon fibre composites - stiff, strong, lightweight, but fail catastrophically, especially in compression
Metal CFRP
Compressive test method: premature failure, underestimated strength and large variability
Compressive non-linearity of angle-ply Fibre fragmentation of 0° plies Pseudo-ductility in compression
1.Main Features of Tensegrity
1) Truss-like structure
2) Prestressed, self-equilibrated
3) Discontinuous compressive members
4) Continuous tensile members
Tensegrity Art Form
Tensegrity Super Ball Bot from
NASA
2.Tensegrity Form-Finding
Equilibrated Configuration
Topology of Tensegrity Tower
Form-Finding
Method
Case 1: Finite Tensegrity Tower
3.Tensegrity/Origami Structure Case 2: Infinite Tensegrity Tower
Topology of Infinite Tensegrity Tower
Origami Dual of Infinite Tensegrity Tower
Section of Infinite Tensegrity Tower
DualityDisplay
Self-equilibrated infinite tensegrity tessellations with a developable Origami dual.
Extract
Topology
Results
Tessellations for Tensegrity/Origami MetamaterialsKeyao Song
Predicting Trans-laminar Fracture Using VCCT and In-situ CT ScansXiaoyang Sun
X. Sun, S. Takeda, M.R. Wisnom, X. Xu
In-situ CT scan & Virtual Crack Closure Technique (VCCT) are used to predict the failure propagation of the large stiffened panel.
(a) 0°
(c) -45°
(b) 90°
(d) 45°
7%accuracy vsexperiment
Predicting LARGE panels using small coupons is difficult, due to size effect.
R-curveDamage zone stateIn-situ CT scan
1 mm
25 mm
Collaborative layup
“Best of both worlds”:
• Strength + Reliability of robot• Skill and dexterity of a human
Tactile sensing
• Real time detection of defects• Detecting ‘type’ of defects
Tactile sensing/collaborative layupMichael Elkington
Project Summary
• Imperial College London are pursuing the incorporation of porous aerogels to boost the storage functions of composite laminates to create structural supercapacitors.
• Aerogels are stiff and brittle which presents a challenge for manufacturing of complex components.
• This project is investigating the formability and manufacturability of composites when divided into structural power and purely structural areas.
Forming simulationIdentify areas of high shear as a the ply is formed over the shape.
Segmenting multi- functional and structural areasAreas of high shear deformation and out of plane curvature are designated as purely structural. Areas of low deformation and curvature are designated for energy storage.
Manufacturing Composites with Structural and Energy Storage FunctionsMark Turk
A Digital Image Correlation (DIC) technique for measuring Chemical Cure Shrinkage (CCS) evolutionJames McArdle
Results• Smallest spacing (largest
confinement) corresponded to highest measured strain (A>C>B>D)
• Peak strains concentrated at edges of confinements
Str
ain
A
CBD
Gelation window
Degree of cure (D.O.C)
Project Challenge• Measure process induced
strain as resin transitions from liquid polymer to glassy solid
A
0.5 mm
1.0 mm1.0 mm
B
CD
Experimental arrays
1.5 mm
DIC strain map
Material variability
Process variability
Laminate Thickness
Requirements
MaterialVariability
ProcessVariability
Predicted Cured Ply Thickness
Tight dimensional tolerances
Laminate Thickness ControlKate Gongadze
A. Burrows et al., Separ. Purif. Technol., 212 (2019), pp. 545-554.
Photoresponsive metal-organic framework composites for gas trappingHarina Amer Hamzah
Materials for sustainable energy applications
Photoresponsive metal-organic framework composites
Thermo-responsive gas trapping in PW@TE7 composite
Maximum pressure up to 200 bar Temperature range 77-773 K High pressure CO2 and H2
Thermo-responsive gas trapping in paraffin wax coated activated carbon compositesPrasanth K Prabhakaran
100 µm
TE7 AC PW@TE7
100 µm
Paraffin wax (PW)
MeasurementsPreparation
Mechanism
I II III IV
Molten PW >55 ᵒC permeable to gases
Solid PW at 25 ᵒC physical barrier to gases
Solid PW at 25 ᵒC under vacuum Gas trapped
Molten PW >55 ᵒC Gas desorbed
Questions?Please speak with presenters at their postersGanapathi Ammasai SengodanIoannis TopalidisRiccardo Manno Stephane FournierDavid Brigido Francescogiuseppe MorabitoXun WuKeyao SongXiaoyang SunMichael ElkingtonMark TurkJames McArdleKate Gongadze Harina Amer HamzahPrasanth Prabhakaran
[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]