experimental analysis of bamboo and e-glass fiber
TRANSCRIPT
Journal of Materials Science and Engineering B 6 (5-6) (2016) 153-160 doi: 10.17265/2161-6221/2016.5-6.005
Experimental Analysis of Bamboo and E-Glass Fiber
Reinforced Epoxy Hybrid Composite
Daniel Redda* and Abiy Alene
School of Mechanical and Industrial Engineering, Addis Ababa University, King George VI Street -385, Ethiopia
Abstract: The main objective of this research is to investigate the performance of bamboo and E-glass fiber reinforced epoxy hybrid composite (BEGRC) for various applications. Initially, manual bamboo fiber extraction method was applied on Ethiopian highland bamboo species “Yushania Alpina” and soaked in a 5% NaOH to remove lignin and hemicellulose from fibers. Next, the bamboo and E-glass fiber test specimen was fabricated with 45% total fiber volume fraction and tensile, compressive, in-plane shear and flexural tests were carried out using universal testing machine. In the case of bamboo to E-glass fiber ratio of 50 : 50, it has high elastic modulus and better compressive strength. Therefore, it is clear that that bamboo and E-glass reinforced epoxy hybrid composite can be applied to various systems that require light weight and high strength. Key words: Bamboo, E-glass fiber, epoxy, hybrid composite, alkaline.
1. Introduction
Most of modern industrial artifacts such as wind
turbine blades, aircraft, ship and automotive parts are
manufactured from massive amount of synthetic
fibers. However these synthetic fibers have many
drawbacks from the fact that non-recyclable,
environmental pollution and high costs. From this
aspect, attention has given to materials such as
vegetable fibers including jute, wastes from industry,
mining and agricultural products for engineering
applications to control environmental degradation and
to minimize cost [1, 2].
Natural fibers have been popular reinforcement
material for fiber reinforced polymer composite
developments. These reinforcement can replace the
conventional fiber, such as glass as an alternative
material. Other than these natural fibers, bamboo is
another interesting material considered as plant fiber
& has a great potential to be used in polymer
composite industry [3-6]. According to Ref. [4-8], it is
known that bamboo is one of the ecological materials
*Corresponding author: Daniel Tilahun Redda, Ph.D., research fields: mechanical design, tribology and materials engineering.
for which it has many distinct characteristics: it
reaches its maximum strength in just few years, it is
renewable material and have simple production
process, have fairly good mechanical properties with
high specific strength, non-abrasive, eco-friendly and
bio-degradability characteristics, have low cost and
weight [8, 9]. This study has two parts. The first part
of the study focused on bamboo fiber extraction from
bamboo culm and fiber treatment. The second part
focused on experimental investigation of tensile,
compressive, flexural and in-plane shear strength of
bamboo and E-glass-fiber reinforced epoxy hybrid
composite.
2. Materials
In this work, System #2000 epoxy resin and System
#2060 hardener (Fiber Glast Development
Corporation, USA) were used. The bamboo fibers is
extracted in this work from Ethiopian highland
bamboo (Yushania Alpina) collected from Injibara,
North West part of Ethiopia, in green form. A UD
E-glass fibers were used for bamboo fibers
reinforcement, which is obtained from Dejen Aviation
(Davi), Bishoftu, Ethiopia.
D DAVID PUBLISHING
Experimental Analysis of Bamboo and E-Glass Fiber Reinforced Epoxy Hybrid Composite
154
2.1 Bamboo Fiber Extraction
There is After nodes, most inner parts and outer
thin layer of exoderm of the highland bamboo have
been removed, the remaining parts have cleaved in
longitudinal direction to thin strips using band saw.
Then these strips are bundled and kept in water for
five days in order to soften them. After removing, they
are beaten gently at slow constant impact load using
rubber hammer in order to loosen and separate the
fiber (Fig. 1a). The resulting fiber bundle is combed
using wire comb. (Fig. 1b). Next these fibers were so-
aked in 5% NaOH solution for 24 hours at 60 ºC in the
in oven dry to remove excess fats from individual
fiber (Fig. 1c).
Finally the fibers washed many times in distilled
water, and dried under the sun for four weeks. At the
end, fibers with a diameter of 170-300 μm and length
of 0.35-0.4 m were selected as hybrid reinforcement.
Finally these fibers were prepared manually in
unidirectional manner (Fig. 1d).
2.2 Preparation of Test Specimen
The BGREC is prepared on the 1,500 mm 500
mm 2 mm size of aluminum plate as a mold. The
plate mold was first coated with polyvinyl alcohol
solution (PVA) and then coated three times with thin
layer of paste wax to easily release composite from
mold. BEGRC specimen was fabricated with 45%
fiber volume fraction using vacuum bagging assisted
hand lay-up technique (Fig. 2). Impregnation process
is carried out manually (Fig. 3a).
A [0/90/0/90]s laminae orientation was used to
produce 2.5mm composite plate thickness for tensile
testing. Compressive and bending test specimens were
prepared as [902/02/-45/45]s laminae orientation
according to ASTM standard that gave 4 mm thick
(a) (b) (c) (d)
Fig. 1 Bamboo fiber extraction process.
Fig. 2 Flowchart of fabrication process of laminated composite using VBAHT.
Experimental Analysis of Bamboo and E-Glass Fiber Reinforced Epoxy Hybrid Composite
155
Fig. 3 Composite fabrication by vacuum bagging system: (a) impregnation & lay-up, (b) consolidation, (c) curved BEGRC and ( d) aluminum mold.
composite plate. Similarly In-Plane Shear coupon was
prepared by off-axis tensile tests of a ± 45º (+ 45º and
– 45º lamina) orientation and produce 2.5mm thick
composite plate.
Then in consolidation stage, vacuum bagging
materials are applied to draw excess air (Fig. 3b).
Next solidification stage is processed at 80 bars of
pressure and 25 ºC with in 2 hrs. Finally it dried for 24
hrs. at room temperature. A [0/90/0/90]s laminae
orientation were used to produce 2.5 mm composite
plate thickness for tensile testing. Compressive and
bending test specimens were prepared as
[902/02/-45/45]s laminae orientation according to
ASTM standard that gave 4mm thick composite plate.
Similarly In-Plane Shear coupon was prepared by
off-axis tensile tests of a ± 45º (+ 45º and – 45º lamina)
orientation and produce 2.5 mm thick composite plate.
Middle plane was used in order to separate the
composite in to two half thickness of laminate
symmetrically as well as in order to keep the balance
of the stack. This assists the composite not easily to
delaminate during the loading. Generally, 9 laminae
for tensile, 15 laminae for shear, 14 laminae for
compressive & bending test specimens are used.
3. Results and Discussion
3.1 Results
Tensile tests, in-plane shearing test compressive
tests and bending tests were performed with Universal
Testing Machine (UTM) with cross head speed of 2,
2, 3 and 5 mm/min respectively.
Typical stress-strain curves for BEGRC under
tensile loading, in-plane shear loading, compression
loading and three point bending load is presented in
Figs. 4a, 4b, 4c and 4d, respectively.
3.2 Discussion
3.2.1 Tensile Test
From Fig. 4a, tensile stress increased linearly with
increase in strain until point of ultimate load under
tensile loading. Above this point, the stress–strain
curve showed sharp, staggered decreases in load and
fracture. Laminate under a tensile loading, a kink is
observed in few specimens in the graph indicating the
BEGRC load and the curve continues with increasing
load, but with a smaller slope, signifying a reduced
stiffness in the direction of the load. Tensile fracture
of unidirectional is mainly longitudinal cracking of
fibers.
The minimum ultimate strength is 187.73 MPa for
bamboo alone composite and the maximum value is
557.29 MPa for E-glass alone composite (Fig. 5). In
general, we concluded that as increase of bamboo
fiber percentages, the tensile strength decreases
slightly.
3.2.2 In-Plane Shearing Test
The typical stress–strain curves for BGREC under
in-plane shearing load and ultimate stress with
percentage of bamboo & E-glass fiber ratio was
presented in Fig. 4b. This graph showed that shear
stress increased linearly with increase in strain until
point of ultimate load under shearing load. Above
this point, the stress-strain curve showed a slow
decrement in load and failure happened at ultimate
Experimental Analysis of Bamboo and E-Glass Fiber Reinforced Epoxy Hybrid Composite
156
(a) (b)
(c) (d)
Fig. 4 Stress vs Strain curve for (a) tensile, (b) in-plane, (c) compressive and (d) flexural loading.
Fig. 5 Comparison of different bamboo/ E-glass ratio tensile peak value.
failure point. The minimum shear strength is 18.18
MPa for bamboo alone composite and the maximum
value is 97.55 MPa for 30 : 70 ratio (Fig. 6).
3.2.3 Compressive Test
Fig. 4c indicated that compressive stress increased
with an increment of strain until point of ultimate
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.080
100
200
300
400
500
600
ENGINEERING STRAIN (mm/mm)
EN
GIN
EE
RIN
G S
TR
ES
S M
Pa)
Bamboo:E-glass=0:100
Bamboo:E-glass=15:85
Bamboo:E-glass=30:70
Bamboo:E-glass=50:50
Bamboo:E-glass=70:30
Bamboo:E-glass=100:0
0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.050
10
20
30
40
50
60
70
80
90
100
110
IN-PLANE SHEAR STRAIN (mm/mm)
IN-P
LAN
E S
HE
AR
ST
RE
SS
(M
Pa)
Bamboo/E-glass=15:85
Bamboo/E-glass=30:70
Bamboo/E-glass=50:50
Bamboo/E-glass=70:30
Bamboo/E-glass=100:0
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.080
20
40
60
80
100
120
140
160
ENGINEERING COMPRESSIVE STRAIN (mm/mm)
EN
GIN
EE
RIN
G C
OM
PR
ES
SIV
E S
TR
ES
S (
MP
a)
Bamboo:E-glass=15:85
Bamboo:E-glass=30:70
Bamboo:E-glass=50:50
Bamboo:E-glass=70:30
Bamboo:E-glass=0:100
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
50
100
150
200
250
300
350
400
450
500
FLEXURAL STRAIN (mm/mm)
FLE
XU
RA
L S
TR
ES
S (
MP
a)
Bamboo:E-glass=15:85
Bamboo:E-glass=30:70
Bamboo:E-glass=50:50Bamboo:E-glass=70:30
Bamboo:E-glass=0:100
187.73
414.72
513.52 520.56 534.11 557.29
186.32
354.64
475.18 470.92 463.07489.62
4.59 5.96 5.99 7.32 7.49 7.090
100
200
300
400
500
600
100:0 70:30 50:50 30:70 15:85 0:100
Ultimate Tensile strength (MPa)Failure strength (MPa)Elongation at Break (%)
Bamboo:E‐glass fiber ratio in Tensile test (%)
Maxim
um Value
E
stress under
the stress–st
This graph
non-linear, i
is jerky/st
compressive
buckling of
According
properties
as the angle
0°. In this
are same i
Fig. 6 Comp
Fig. 7 Comp
2
4
6
8
10
Maxim
um Value
Experimental
r compressiv
train curve s
h shown tha
in which the
tick-slip be
e stress of BE
specimens.
g to the
of compos
of orientatio
study, fibe
i.e. unidirec
parison of diffe
parison of diffe
18.18
0
20
40
60
80
00
10
Bam
l Analysis of
ve loading. A
showed non-
at the incre
responsible
ehavior. D
EGRCs rapidl
Tsai-Hill cr
ites continu
on of the fiber
ers direction
ctional, but
erent bamboo/
erent bamboo/
8
6
17.79
1.34
00:0
mboo:E‐gla
MaximumFailure stFailure st
Bamboo and
Above this po
-linear segme
ement value
for this respo
During fract
ly decreased w
riteria [7],
uously decr
rs increases f
in all lam
ply angles
/E-glass ratio i
/E-glass ratio c
69.7165.24
4.95
70:30
ass fiber ra
m In‐plane Strength (MPtrain (%)
d E-Glass Fibe
oint,
ents.
e is
onse
ture,
with
the
rease
from
minae
are
diff
an
of
stre
stre
unid
F
stre
yiel
com
valu
114
in-plane shear
compressive pe
84.3182
4
50:50
tio in In‐pl
Shear strengPa)
er Reinforced
ferent in all t
increment in
middle laye
ength obtaine
ength which
directional w
Fig. 7 illustra
ength, failure
ld strength.
mpressive- str
ue is obtaine
4.13 MPa.
peak value.
eak value.
97.55
2.45
4.18
0 3
lane Shear
th (MPa)
d Epoxy Hybr
type of BEG
n numbers o
ers fibers fro
ed is much
are all fib
way.
ated the pea
e strength, f
Ratio of 50
rength, 146.2
ed from the
5 991.96
5.27
30:70
r test (%)
rid Composit
GRCs samples
of layers and
om 0º, the
lower than
bers of lami
ak values of
failure strain
: 50 record
22 MPa; And
15 : 85 rat
94.21 93.9
4.82
15:85
te 157
s. So, due to
d orientation
compressive
n the tensile
inate are in
compressive
and (0.2%)
ded a higher
d a minimum
tio, which is
94
2
7
o
n
e
e
n
e
)
r
m
s
E
158
3.2.4 Flex
From Fig
increase in
stress unde
stress-strain
peak value
failure strain
clearly illust
concentrated
where load
strength is 3
maximum v
Bamboo, E
fluctuations
recorded du
tests.
The load
Responsible
rates and sm
used during
Modulus
and flexural
Fig. 9. The
modulus for
and 11,588 M
As we o
modulus is
Fig. 8 Comp
Experimental
xural Test
. 4d flexural
strain until
r bending l
curve show
of flexure r
n of each BG
trated in figu
d near the m
d was appli
376.17 MPa f
alue is 478.3
-glass & ep
of stress-str
uring uniaxia
oscillations h
e for this stic
mall specim
UTM test [10
of elasticity f
l tests also
minimum an
r these comp
MPa respectiv
observe from
recorded in a
parison of diffe
l Analysis of
stress increa
point of m
load. Above
wed non-linea
rupture, failu
GREC ratio in
ure 8. Here, b
middle of th
ed. The mi
for 70 : 30 co
5 MPa for 0
oxy bond re
rain curve (
al compressi
happened due
ck-slip is due
ens with slo
0].
for tensile, sh
determined,
nd maximum
posites are fo
vely.
m the graph,
a 50 : 50 rat
erent bamboo/
Bamboo and
ased linearly w
maximum flex
this point,
ar segments.
ure strength
n bending loa
bending fract
he test speci
inimum flex
omposite and
: 100 compo
evealed a str
(slip-stick eff
ion and ben
e to the stick-
e to small st
ow loading r
hear, compres
as illustrated
values of ten
ound to be 3
a good ten
tio of bambo
/E-glass ratio f
d E-Glass Fibe
with
xure
the
The
and
ad is
tures
imen
xural
d the
osite.
rong
ffect)
ding
-slip.
train
rates
ssive
d in
nsile
3211
nsile
oo to
E-g
dete
for
valu
com
S
5,04
indi
E-g
the
load
3
F
the
exh
failu
100
failu
It
grip
first
foll
prop
attr
dela
inta
dela
flexural peak v
er Reinforced
glass fiber ra
ermined, and
50 : 50 rat
ues. As wel
mposites vary
Similarly, the
47.7 and 7,6
icates that th
glass ratio has
tests carried
d-bearing cap
3.2.5 Failure M
Fig. 10 and T
specimens.
hibited simila
ure types at t
0 : 0 ratio, t
ure types.
t also observ
ps & multim
t matrix (adh
lowed by fi
pagates spon
ibuted by
amination. Th
act areas of
amination buc
value.
d Epoxy Hybr
atio. Shear m
3,568 MPa f
tios were a m
ll the compr
y between 1,9
e flexural mo
681.26 MPa.
he BEGRC w
s relatively hi
out. As a res
pacity.
Modes Identi
Table 1 show
All specime
ar failure m
the middle of
types of fail
ved that some
ode types. F
hesive betwe
fibers failure
ntaneously. C
micro bu
he delaminat
the laminat
ckling and gro
rid Composit
modulus of e
for 100 : 0 an
minimum an
ressive mod
06 and 2,630
odulus also v
This observ
with 50 : 50
igher moduli
sult, this ratio
ification
w the mode o
ens under ten
modes; that
f gage area. I
lure identifie
e specimens s
or all layers
een fibers) fa
e through th
Compressive
uckling surr
ted portions s
te by a com
owth, the buc
te
lasticity also
nd 5,418 MPa
nd maximum
duli of these
0 MPa.
vary between
vation clearly
0 bamboo to
in almost all
o has a better
of failures of
nsile loading
is explosive
In the case of
d are lateral
start to fail at
of laminate,
ailure occurs
hen fracture
failure was
rounded by
spread to the
mbination of
ckling further
o
a
m
e
n
y
o
l
r
f
g
e
f
l
t
,
s
e
s
y
e
f
E
Fig. 9 Comp
Fig. 10 (a) I
Table 1 Mo
Loading cond
Tensile
In-plane shear
Compressive
Flexural
enhancing
culmination
stiffness of s
In the ca
specimens f
of gage are
edge delami
failure on th
matrix and
surface was
Experimental
parison of You
Intact coupon u
de of failures u
dition
r
the growth
of this last
specimens.
ase of in-plan
failed by later
a; and only
nation. In the
he tension sur
fiber breakag
due to buckli
l Analysis of
ung’s Modulus
under tension
under differen
ASTM
D3039
D3518/
D3410
D790
h of dama
event is the
ne shearing t
ral failure typ
a few specim
e case of flexu
rface of speci
ge while on
ing of specim
Bamboo and
for different f
and compressi
nt loading cond
standards
/D3039
ged area.
complete los
test, most of
pe, in the mi
men’s failure
ural test, bend
imens was du
the compres
mens.
d E-Glass Fibe
fiber ratio.
ion loading an
ditions.
M
X
A
A
B
The
ss of
f the
ddle
e by
ding
ue to
ssive
4. C
T
hyb
tens
Firs
Eth
Alp
furt
Sec
er Reinforced
d (b) intact cou
Mode of failure
XGM, LGM
AGM, DGM, L
AGM, BGM, T
BBB, CBT, MU
Conclusion
The performa
brid composit
sile, compres
st, manual me
hiopian high
pina” was und
ther lignin an
cond, differen
d Epoxy Hybr
upon under sh
es identified in t
LGM
AT
UV, TAM
ns
ance of bambo
te (BEGRC) w
ssive, in-plane
ethod of bam
hland bamb
dertaken and
nd hemicellus
nt mechanica
rid Composit
hear and bendi
terms of codes
oo and E-gla
was investiga
e shear and f
mboo fiber ext
boo species
a 5% NaOH
slose remova
al properties
te 159
ing load.
ass reinforced
ated based on
flexural tests.
traction from
“Yushania
was used for
al from fiber.
of BEGRC
9
d
n
.
m
a
r
.
C
Experimental Analysis of Bamboo and E-Glass Fiber Reinforced Epoxy Hybrid Composite
160
were determined from different bamboo to E-glass
fiber percentage of 45% total fiber volume. Thus, the
following results are obtained:
The tensile, compressive, shear and flexural
properties of BEGRC composites depends
fundamentally on the amount layers in a laminate,
angle and orientation of lamian and bamboo to E-glass
fiber percentage presences in the composite.
High modulus of elasticity and compressive
properties are obtained from bamboo to E-glass
reinforced fiber ration of 50 : 50.
For a selected bamboo species, a three years old of
extracted bamboo fiber is good enough to use as
reinforced in structural fibers.
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