evaluation on the structural performance of sandwich composite...
TRANSCRIPT
Evaluation on the Structural Performance of
Sandwich Composite Beams for Railway Sleepers
Presenter:
Wahid FerdousPhD Candidate (Structural Engineering)
University of Southern Queensland
Toowoomba, Queensland 4350, Australia
Authors:
Wahid Ferdous, Allan Manalo and Thiru Aravinthan
2
Overview
• Introduction of the Research
• Materials and Casting Method
• Experimental Program
• Static Behaviour of Beams
• Discussion
• Application
• Conclusion
3
Introduction
• Rotting
• Splitting
• Insects attack
• Scarcity
• Corrosion
• Electrical conductivity
• Fatigue cracking
• Difficulty of packing
• Heavy weight
• High initial cost
• Low impact resistance
• Chemical attack
Timber Sleeper Steel Sleeper Concrete Sleeper
Composite Sleeper
Pro
ble
ms
Solution:
4
Types of Existing Composite Sleepers
Long Longitudinal Directional Fibres(Type 2)
Fibres in All Directions(Type 3)
Short or No Fibres (Type 1)
Materials:Recycled plastic such as plastic cups, bottles, bags etc.
Materials:Urethane resin foam is reinforced with long glass fibres
Materials:Sandwich panel, Pultruded composite etc.
Examples:TieTek, Axion EcoTrax, IntegriCo, I-Plas, Tufflex, KLP, MPW sleepers etc.
Examples:FFU synthetic sleeper
Examples:Glue laminated sleeper, Hybrid sleeper etc.
5
Performance of Composite Sleepers
Performance measurement AREMA specification
Oak Softwood Glue lam Type-1 Type-2 Type-3
Density, (kg/m3) 1096 855 960 850-1150 740 1040-2000
Modulus of elasticity, (GPa) 8.4 7.4 12.0 1.5-1.8 8.1 5.0-8.0
Modulus of rupture, (MPa) 57.9 49.3 66.9 17.2-20.6 142 70-120
Shear strength, (MPa) 5 4 4 4 10 15-20
Rail seat compression, (MPa) 4.6 3 3.9 15.2-20.6 28 40
Screw withdrawal, (kN) 22.2 13.3 n/a 31.6-35.6 65 > 60
6Typical composite sleeper concept
Mould
Sandwich
Panel
Polymer Matrix
• Excellent strength and stiffness to weight ratio• Can be engineered according to the requirements• Excellent resistance to environmental effect
Materials and casting method
• Sandwich Composite• Polymer Matrix
7
Test Properties GFRP skin Core
Long Trans
Flexure Modulus (GPa) 14.28 3.66 1.33
Strength (MPa) 317.4 135.1 14.3
Peak strain (%) 2.29 5.26 1.22
Tension Modulus (GPa) 15.38 12.63 1.03
Strength (MPa) 246.8 216.3 5.97
Peak strain (%) 1.61 2.37 0.61
Poisson’s ratio 0.25 0.13 -
Compression Modulus (GPa) 16.10 9.95 1.33
Strength (MPa) 201.8 124.2 21.3
Peak strain (%) 1.24 1.25 4.04
Poisson’s ratio - - 0.29
Shear Modulus (GPa) 2.47 2.17 0.53
Strength (MPa) 23.19 21.81 4.25
Peak strain (%) 3.08 2.38 0.81
Properties Values
Tensile strength (MPa) 14.74
Tensile strain at peak 0.042
Compressive strength (MPa) 65.46
Compressive strain at peak 0.054
Density (gm/cm3) 1.38
% Porosity 0.62
Glass transition temperature (0C) 64
Sandwich panel
Polymer matrix
8
Experimental program
1.8 mm5 mm
16.4 mm
1.8 mm
5 mm
1.8 mm
16.4 mm
1.8 mm
16.4 mm
16.4 mm
5 mm1.8 mm
5 m
m
= 80 mm
5 m
m
1.8 mm
= 90 mm
= 1
05 m
m
1.8
mm
5m
m
16.4
mm
1.8
mm
5m
m
1.8
mm
16.4
mm
1.8
mm
16.4
mm
16.4
mm
5m
m1
.8 m
m
5 mm
= 8
0 m
m
5 mm
1.8
mm
=
90 m
m
= 105 mm
Spreader beam
Load
Cell
Hydraulic
Cylinder
1400 mm
Experimental beam
Laser distance sensor
Beam
ID
Shear
span
(mm)
Width
(mm)
Depth
(mm)
Orientation
b D
F-A200 200 90 105 Flatwise
F-A400 400 90 105 Flatwise
F-A600 600 90 105 Flatwise
E-A200 200 105 90 Edgewise
E-A400 400 105 90 Edgewise
E-A600 600 105 90 Edgewise
(a) flatwise orientation (b) edgewise orientation (c) test setup (d) beam details
9
Failure behaviour of beams
F-A200 F-A400 F-A600
E-A200 E-A400 E-A600
10
0
20
40
60
80
100
0 35 70 105 140
Lo
ad
(k
N)
Displacement (mm)
Core tension
Skin compression
Skin tension
Core shear
F-A600
F-A400
F-A200
E-A200
E-A400
E-A600
static behaviour of beams
Beam
identity
Peak load Flexural
strength
Shear
strength
Elastic
modulus
(kN) (MPa) (MPa) (GPa)
F-A200 90.5 54.72 7.18 3.08
F-A400 51.0 61.68 4.05 3.01
F-A600 26.8 48.62 2.13 3.08
E-A200 75.8 53.47 6.02 2.83
E-A400 40.2 56.72 3.19 2.67
E-A600 29.2 61.80 2.32 2.87
𝑀𝑂𝑅 =𝑃
4𝐼𝑒𝑓𝑓; 𝐸𝐼 𝑒𝑓𝑓 =
3𝐿2 − 4 2
48
∆𝑃
∆𝑣𝜏 =
3𝑃
4 ;
11
discussion
0
20
40
60
80
0 200 400 600 800
Fle
xu
ral
stre
ng
th (
MP
a)
Shear span (mm)
Flatwise
Edgewise0
2
4
6
8
0 200 400 600 800
Sh
ear
stre
ng
th (
MP
a)
Shear span (mm)
Flatwise
Edgewise0
1
2
3
4
0 200 400 600 800
Ela
stic
mo
du
lus
(GP
a)
Shear span (mm)
Flatwise
Edgewise
(a) effect on flexural stress (b) effect on shear stress (c) effect on elastic modulus
12
Application – Composite Railway Sleeper
Cases Bending strength
(MPa)
Shear strength
(MPa)
Elastic modulus
(GPa)
𝑀𝑂𝑅 𝜏 𝐸𝑎𝑝𝑝
Sandwich beam 49-62 6.0-7.2 2.7-3.1
Timber sleeper 47-110 2-7 7-26
AREMA specification 13.8 6.2 1.17
• Sandwich beam can meet the strength requirements of composite railway sleeper
13
conclusion
• The orientation of the beam plays a significant role on the failure behaviour.
• The flexural stress increases and shear stress decreases with the increase of shear spans.
• The flatwise orientation provided higher effective modulus of elasticity than the edgewise
beam. However, the shear span has no effect on the elastic modulus of the beam.
• The capacity of resisting high bending and shear forces and ease of controlling the depth,
makes the edgewise orientation a preferable choice than flatwise orientation for railway
sleeper.
14
Thanks for your attention
Acknowledgement• University of Southern Queensland for financial and material supports through Australian
Postgraduate Award (APA) scholarship
• Supports from the Department of Industry Innovation, Science, Research and Tertiary Teaching
Enterprise Connect Researcher-In-Business Funded by the Australian Government.
Contact InformationWahid Ferdous
Email: [email protected]