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OverviewOverview
Research area Research area Most recent projects highlightsMost recent projects highlights
Dr. Elaheh Ghassemieh
Mechanical Engineering Department
University of Sheffield
Research areasResearch areas
Novel materials and their processes
Bio-composites
Biodegradable polymers
Ceramics
Titanium alloys
Scaffold, dental implants, membranes
Packaging
Natural based fibre composites
Hemp, flax, palm fibre In thermoplastic-thermoset
Body panels Automotive –Transport
Packaging
Biomaterials, automotive, packaging, oil& petroleum industry
Nano-composites
Nano tubes
Nano clay
In elastomers
High pressure and temperature seals
Wear resistant rubber
Nonwovens
Optimised/novel manufacturing processesOptimised/novel manufacturing processes
Aerospace, Automotive
Ultrasonic consolidation
3 dimensional hybrid metal structures
Adaptive metal structures
Ultrasonic welding
Thermoplastic and NF composites
Titanium /CFC stack
Aluminium /CFC stack
Optimised drilling process
Hydroentanglement
Research Areas (continued)
1. Nanocomposite of elastomers for enhanced life in Harsh Environment
2. Optimisation of the geometry of the drill bit and process parameters for cutting hybrid composite/metal structures in new aircrafts
3. Bio-Degradable Sintered Composites of PLA and HA in Scaffolds
4. Ultrasonic welding of the composites
5. Green/recyclable composites for reduced carbon footprint in automotive/sustainable development applications
6. Design, manufacture and characterization of patient specific porous titanium based implant
7. Embedding Active/Passive elements in Adaptive Structures using Ultrasonic consolidation
8. Developing pressure sensitive adhesive with better efficacy in health/personal care applications
9. Large Strain Behaviour of Syntactic Foam Damping Material
10. The influence of the interface lute on the integrity of machined ceramic restorations
11. Novel hybrid nano-elastomers designed for longer fatigue life and improved energy absorbing properties
12. Coating of elastomers for reduced permeability and high wear resistance
Mos
t rec
ent p
roje
cts
Mos
t rec
ent p
roje
cts
Research team
PhD students
Mr. Rahul CadambiMr. Ozden Isbilir
Mr. Davood RouholaminMr. Graham Gagg
Mr. Teddy MbwadzawoMs. Hoda AmelMr. Farhan Raza
Mr. Marton HuszarMs. Shirin SharhbafMr. Cheeseng Tan
Nanocomposite of elastomers for enhanced life (high pressureNanocomposite of elastomers for enhanced life (high pressure--temperature)temperature)
•Optimizing the processing of nanocomposites•Enhance the resistance to explosive decompression•Increase the life and performance of the elastomer
XRD Graphs for CLOISITE 15A
0
50
100
150
200
250
3 4 5 6 7 8 9 10 11 12
Angle 2θ
Rel
ativ
e In
tens
ity
C15A As RecdC15A Freeze DriedC15A 30 mins SonicationC15A 96h Ball Milling
0
5
10
15
20
25
30
35
HNBR Std HNBR C15A FD HNBR C20FD HNBR KC
Tens
ile S
tren
gth,
MPa
0
50
100
150
200
250
300
350
Elon
gatio
n at
bre
ak, %
tensile @ room temp
tensile @ 100°Celongation @ room temp
elongation @ 100°C
0
2
4
6
8
10
12
0.01 0.1 1 10 100
Particle Diameter, µm
Volu
me, %
As Received C15A
C15A 96h Ball Milled
C15A 48h Ball Milled
C15A 72h Ball Milled
• Improving the life of the tool and reducing the wear on drill• Preserving the quality of the holes produced, reduced
delamination and burr formation
Optimisation of the geometry of the drill bit and process parameOptimisation of the geometry of the drill bit and process parameters for ters for cutting hybrid composite/metal structures in new aircraftscutting hybrid composite/metal structures in new aircrafts
0
50
100
150
200
250
300
350
1 5 9 13
Forc
e (N
)
first runsecond run
CFC
• Optimisation of the process parameters for best quality weld and embedding• Understanding the mechanism of the process using FE simulation • Quantifying the effect of the process parameters on the two dominant effect
during process
Embedding Active/Passive elements in Adaptive Structures using Embedding Active/Passive elements in Adaptive Structures using Ultrasonic consolidationUltrasonic consolidation
ts
Substrate
Foil
S onotrode
w
tf
fV
P applied
2 m m2 m m
1 m m
P a th , para lle l to the d irec tion o f v ib ra tion
ts
Substrate
Foil
S onotrode
w
tf
fV
P applied
2 m m2 m m
1 m m
P a th , para lle l to the d irec tion o f v ib ra tion
ts
Substrate
Foil
S onotrode
w
tf
fV
P applied
2 m m2 m m
1 m m
ts
Substrate
Foil
S onotrode
w
tf
fV
P applied
2 m mts
Substrate
Foil
S onotrode
w
tf
fV
P applied
ts
Substrate
Foil
S onotrode
w
tf
fV
P applied
Substrate
Foil
S onotrode
w
tf
fV
P applied
2 m m2 m m
1 m m
P a th , para lle l to the d irec tion o f v ib ra tion
0
2
4
6
8
10
12
14
8.4 10.4 12.4Amplitude of ultrasonic vibration (μm)
Fric
tion
wor
k (m
J/m
m2 )
900
1100
1300
1500
1700
1900
2100
Frac
ture
Ene
rgy
(J/m
2 )
-250
-200
-150
-100
-50
0
50
100
150
200
250
-1.6 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 1.6
Strain (%)
Stre
ss (M
Pa)
BioBio--Degradable Sintered Composites of PLA and HA in ScaffoldsDegradable Sintered Composites of PLA and HA in Scaffolds
• Processing of biodegradable composite scaffolds of PLA and HA through sintering and porogen leaching.
• Evaluation of the suitability of the manufactured composite for scaffold applications.
0
5
10
15
20
25
30
35
0 - 100 100 - 200 200 - 300 300 - 400 400 - 500 500 - 600 600 - 700
Equivalent pore diameter (Microns)
Freq
uenc
y (%
)
Top faceBottom face
PLA / HA scaffolds
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90Strain (%)
Stre
ss (M
Pa)
Stage 2
Stage 3
Stage 1
Neat PLA
HA/TCP
HA and PLA
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
0 10 30 50PLA & (%HA)
Mod
ulus
(MPa
)
Gibson Model (85%)Our test (85%)Gibson Model (90%)Our test (90%)
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
Pure PLA PLA/10%HA PLA/30%HA PLA/50%HA0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
Wall ThicknessDegree of Anisotropyμm
Design, manufacture and characterization of patient specific Design, manufacture and characterization of patient specific porous titanium based implantporous titanium based implant
•Design of the patient specific implant •Manufacturing of the prototype implant using Laser sintering or 3D printing•Characterisation of the implant
Optimisation of the processing of green/recyclable composites foOptimisation of the processing of green/recyclable composites for r reduced carbon footprint in automotive/sustainable development reduced carbon footprint in automotive/sustainable development
applicationsapplications
•Improving adhesion of the fibre and resin using chemical treatments• Manufacturing the natural fibre composite using vacuum moulding or RTM (optimising)• Evaluation of moisture absorption, specific strength an stiffness and impact properties, failure and fatigue.
Developing pressure sensitive adhesive with better efficacy in Developing pressure sensitive adhesive with better efficacy in health/personal care applicationshealth/personal care applications
• New formulations for improving the efficacy of the cold wax strip • Establishing the in vitro tests to replace the most variable and expensive in vivo tests • Identification of the human factors and methods of measuring the variables and their
effects• Establishing the quality check tests on the lab products and new formulations
C-10 Silica (Half Size)
50
55
60
65
70
75
80
85
90
0.1 1 10 100
Frequency (Hz)Ph
ase
Ang
le
3%4%5%5.5%6%6.25%6.50%
180o Peel
0
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18
10mm/s 100mm/s 1000mm/s
Speed
Forc
e (N
) VeetBootsNair
Evaluation of the Design & Performance of Loading & Unloading SyEvaluation of the Design & Performance of Loading & Unloading Systems using stems using Ambulance StretchersAmbulance Stretchers
• Analysis of the loading & unloading of Ambulance Stretchers• Comparison of the Stretcher Systems (Tail-lift, Ramp-winch and easi-loader)• Evaluation of the Risk of Injury for the Ambulance Workers during the process
of loading and unloading
Failure CriteriaL4/L5 Disc : 3.4kN
-300
-150
0
150
300
-30 -15 0 15 30time (s)
forc
e (N
)
MeasuredCalculatedFailure Limit
loading
unloading
0
1
2
3
4
5
-15 -10 -5 0 5 10 15time (s)
com
pres
sion
forc
e (k
N)
AW1 rampAW2 rampfailure limit
0
2
4
6
8
-35 -25 -15 -5 5 15 25 35time (s)
com
pres
sion
forc
e (k
N)
easi-loaderAW1 tail-liftAW2 tail-liftAW1 rampAW2 rampfailure limit
The influence of the interface lute on the structural integrity The influence of the interface lute on the structural integrity of of
full coverage machined ceramic restorationsfull coverage machined ceramic restorations
Resin cement
Cemented machined ceramic crown
Tooth
Standard crown preparation
Ceramic crown
Tooth
Pulp
• the effect of the interface dimensions and the elastic modulus of the lute on the structural integrity of a tooth restored with an adhesively retained full-coverage machined ceramic crown.