Template for for the Jurnal Teknologi
Experimental Test Effect Of Fiber Glass And Direction Of
Strength Matrix Composite Materials Airfoil Profile Fan BladesFull
paperJurnalTeknologi
Sugeng Ariyono, Carli, Ariawan Wahyu Pratomo, Hery
Tristijanto
Department of Mechanical Engineering Politeknik Negeri
Semarang*Corresponding author: [email protected]
Article history
Received XXXXReceived in revised form XXXXAccepted XXXX
Graphical abstract
Abstract
The use of composite materials is nowadays increasingly
widespread. Those materials are not only applied as a cover
material (skin) but also as main structure in the mechanical
construction. Composite materials commonly used are glass fiber
composites (fiber glass composite). The aim of this research is to
develop fan blade made of fiber glass composite. This study
discusses experimental testing for investigating influence of fiber
orientation and matrix material that applied as a fan blade to its
mechanical strength. In present study as composite matrix are epoxy
and polyester. The composite was manufactured using Hand Lay-Up
method and stacked with 6 layers with fiber direction of 0/90 and
45 . The Hand Lay-Up method was chosen because that method is
simple and cheap enough. In addition, the specimens then tested
using bending test machine based on test standard ASTM D 6272, with
the Four-Point Bending method, while for tensile testing using a
tensile testing machine (selvopulser) with the standard test ASTM D
3039. The results showed that the tensile and bending strength of
composite fiber glass/ epoxy composite is higher than the glass
fiber / polyester. Test results also showed that the tensile and
bending glass fiber composite with fiber orientation 0/90 has
higher tensile than the fiber orientation 45 , meanwhile deflection
of the composite with fiber orientation 45 gave higher values (more
elastic).
Keywords: Composites, Hand Lay-Up method, glass fiber / epoxy,
glass fiber / polyester
2012 Penerbit UTM Press. All rights reserved.
Author et al. / Jurnal Teknologi (Sciences & Engineering) 58
(2012) 8588
20 (2012) 85-88 | www.jurnalteknologi.utm.my | eISSN 21803722 |
ISSN 01279696
PAGE 2
1.0 INTRODUCTION
Wind as a source of energy is the most abundant source of
renewable energy. Wind energy will remain there as long as the
earth is getting energy from the sun. One of the tools that utilize
wind mechanical movement is the propeller. Propeller is a component
of the machine which is used to transmit power by converting
rotational motion into thrust [1][2]. The development of current
propeller is very rapid and diverse. Propeller is widely used in
the aerospace industry, maritime, and energy machinery, such as the
manufacture of aircraft, ships, hovercraft, and various types of
turbines [3][4]. Wind turbine has great potential to generate
electricity even though from the data, generally, the wind energy
potential in Indonesia was not great, but based on a survey and
measurement of wind data that has been conducted since 1979, many
prospective areas for wind speed annual average of 3.4 - 4.5 m /
sec or having energies between 200 kWh / m to 1000 kWh / m. This
potential can already be used for small-scale electricity
generation to 10 kW[5].
The most important things in the design of wind turbine blades
are both form and material. Micro win turbine under 5 kW, the blade
is usually made from wood as seen in Figure1. This type of
propeller can receive win speed up to 50 m/sec. For larger win
turbine the blade mostly made of composite either carbon fiber or
glass fiber. Meanwhile most propellers used for aerospace or
hovercrafts are made from fiberglass because it needs larger trust
[6]. In practice, to obtain high efficiency, fan blades must have
certain characteristics, such as a light, stiff, strong, and not
easily affected by the environment (such as corrosion), therefore
the material used for the manufacture of the fan blades must be
appropriately chosen[7].
Composite material is composed of more than one type of material
and designed to get a combination of the best characteristics of
each of its constituent components. Basically, the composite can be
defined as a macroscopic mixture of fiber and matrix. Fiber is a
material that is generally much stronger than the matrix and serves
to provide tensile strength, while the matrix serves to protect the
fiber from environmental effects and damage caused by collision.
Composite has great strength and can be designed based on the need
of it strength. The direction, composition and type of fiber glass
will effect to it strength.
Figure 1.2 kW Wind Turbine with wooden blade
The main benefit of the use of composites is to obtain a
combination of properties of high strength and stiffness and light
weight type. Composite can also be formed in very unique and
complex shape. By choosing an appropriate combination of fiber and
matrix materials, the strength of component can be designed
properly based on the need of it application. This research shows
simple example of the effect of direction of fiber on its strength
by using tensile test, bending test and finally dynamic test on
real condition with CPP machine.
2.0 FABRICATION METHOD
Hand lay-up method was used to manufacture the blade. First step
was to design the shape of blade and using CAM the blade was
manufactured using wood as raw material. Whereas to find the
appropriate direction and composition of fiber, the specimen was
made in 4 different compositions [8]. The specimen was then tested
using tensile test and bending test. Blade pattern made from wood
was used to manufacture mold made of fiber glass. A release agent,
usually in either wax or liquid form, is applied to remove the
finished mold easily from the pattern blade as seen in Figure 2
[9]. The surface of the mold should be polished and lay up with
release agent before it is used to make blade. Lay-up technique
with fiber orientation epoxy 0/90o, the blade was fabricated.
Figure 2. Blade pattern and mold master to fabricate next
blade
3.0 EXPERIMENTAL METHOD AND DISCUSSION3.1 Tensile TestTensile
and bending test specimens ,as seen in Figure 3, were made in the
form of composite plates were manufactured by hand lay-up method,
created in the six layers of glass fiber Woven Roving type (WR).
Geometry and dimensions of the tensile and bending test specimens
adapted to standard ASTM D 3039 and ASTM D 6272 (four point
bending)[10].
Figure 3. size of specimen based on ASTM D3039
Test specimens of composite bending shape refers to the standard
ASTM D 6272 (four point bending), which has dimensions of length =
100 mm and width = 10 mm. Specimen thickness = 3 mm as seen in
figure 4.
Figure 4 specimens of blade material
Tensile test results data using Servopulser engine, with load
(P) by 2 tons (2000 kg) can be seen in the table 1. The table shows
that the results of tensile testing of glass fiber composites with
epoxy resin matrix with fiber orientation 0 / 90 obtained results
tensile test maximum voltage average of 112.8 MPa. As for the Epoxy
45, the average maximum stress of 82.34 MPa. Results of tensile
test for fiber glass with polyester resin matrix with fiber
orientation 0 / 90 tensile test results obtained maximum voltage
average of 118.86 MPa. As for the polyester 45, the average maximum
stress of 90.49 MPa. From the above average results can be seen in
Figure 5.
Table 1. Results of Tensile
test.NoSpecimensThickness(mm)Wide(mm)Length ( Lo )(mm)Tensile mak.(
Mpa )
1Polyester 453,5020,0100,883
2Polyester 453,6521,998,892
3Polyester 453,2021,6597,7595
4Polyester 0/903,1019,5093,7112
5Polyester 0/902,8021,4594,45136
6Polyester 0/903,3019,6589,05107
7Epoxy 454,1021,70101,7861
8Epoxy 452,6022,5091,10105
9Epoxy 453,3521,3098,480
10Epoxy 0/903,0020,2096,7595
11Epoxy 0/903,0519,5096,25124
12Epoxy 0/903,1019,096,50118
Figure 5. Diagram of the influence of the orientation of the
fibers and the matrix of the maximum tensile stress
The average tensile strength from table 1 can be plot into graph
such as in Figure 5. Maximum tensile strength occurs in the second
bar with value 118.86 Mpa. This indicates that the Polyester with
90o fiber direction has better strength compare to Epoxy 0/90o.
Figure 1 indicates that the direction of orientation of the fibers
in the sample influence on mechanical properties, especially
tensile strength composite. Tensile strength was greatest in the
direction of fiber composites with 0 / 90. This can be explained by
looking at the analysis of microscopic stress acting on the
composite. Direction of orientation is important in strengthening
the composite. Since the direction of fiber orientation is closely
related to the deployment of the forces acting on the composite.
Distribution of the maximum fiber occurs when the fiber direction
parallel to the direction of loading. Strength of the composite
will be reduced by changing the angle of the fiber, so that the
composite will have a high strength if the fiber structure and the
force exerted are unidirectional. However, its strength will be
weakened if the structure of both the opposite direction or
perpendicular. Matrix composites have not actually chemically bond
with the filler fibers but only happens bonding interface (bond in
physics). Therefore, in this study showed that for unidirectional
fibers (0 / 90) have the largest tensile strength; this is because
the fiber is unidirectional and perpendicular to the force exerted
on the composite. Fibers are transverse to the direction of loading
does not provide reinforcement, will actually weaken. It is also
due to the unidirectional fibers and fibers that transverse or
perpendicular interfacial bonding does not occur (the fibers) are
against the force of the composite. The greater force is starting
to take some fiber (debonding) because of the pull force on the
tip.
Figure 6 , Left, a fracture with fiber orientation 0 / 90, and
Right, fracture with the fiber orientation 45.
Because of the connective force between the matrix with these
fibers, may also explain why the composite fibers have a tensile
strength 45 smaller than the fiber composite 0 / 90, this is
because the power of connective fiber between the matriknya weak
even weaker than the bonding of atoms in matrix itself.
Consequently when it gets there loading shear force on its matrix
which then separated from the matrix fiber bond.
3.2 Bending TestTesting was conducted using a four point bending
method, the method of measurement have been more accurate results
than the Three-point bending method. The result of bending test can
be seen in Table 2. Table 2. Comparison bending test between
Polyester and EpoxyNoSpesimenBending(Mpa)SpesimenBending(Mpa)
1Polyester 4570.6589Epoxy 4584.7081
2Polyester 4579.9360Epoxy 4580.1861
3Polyester 4583.0580Epoxy 4583.8537
4Polyester 0/9075.9126Epoxy 0/90117.4991
5Polyester 0/9084.7086Epoxy 0/90114.4567
6Polyester 0/9079.1527Epoxy 0/90125.7210
The table shows the bending test results for the fiber glass
with polyester resin matrix and fiber orientation 0 / 90 has an
average stress of 79.92 MPa. Meanwhile the polyester with fiber
orientation of 45 has the average stress of 77.88 MPa. Bending test
results for glass fiber with epoxy resin matrix and fiber
orientation 0 / 90 has an average stress of 119.22 MPa. The epoxy
resin and fiber orientation of 45, has the average stress of 82.91
MPa. Figure 7 shows the average bending test for every
specimen.
In the bending test, at the top of the specimen subjected to
pressure, and the bottom had traction. Failure caused by the
bending test composites fractured at the bottom of not being able
to withstand tensile stress.
Propeller used in this experiment made of glass fiber with epoxy
resin matrix and fiber orientation 0 / 90. This composition has
bending test higher than other, even though the tensile strength is
lower than the fiber glass with polyester resin matrix and fiber
orientation 0 / 90. Higher bending stress give better properties to
withstand dynamic load [11][12]. Propeller especially used as
hovercraft propeller have dynamic load higher than used for wind
turbine.
Figure 7 Diagram of the influence of the orientation of the
fibers and the matrix of the maximum bending stress
Blade fabricated from Multi-Wing was used as bench mark to
design new profile blade used in this experiment. Material used by
Multi-Wing was also tested for comparison in this experiment.
Figure 8 shows the result of the tensile strength.
Figure 8 Diagram of the maximum tensile stress for each test
specimen and the maximum tensile stress to the fan blade from
Muti-Wing
Figure 8 shows that the maximum tensile strength of the
specimens was higher (except Epoxy 45) when compared with products
from Multi-Wing. Multi-Wing products with the axial fan and other
various types that are used for a hovercraft are made from
thermoplastic (glass reinforced polypropylene). The thermoplastic
material has a good flexural modulus when compared with materials
used in this experiment.
3.3 Results and Analysis of Static and Dynamic Testing Fan Blade
using Control Pitch Propeller (CPP)
Control Pitch Propeller (CPP) as seen in figure 9 is used to
test the capacity of the fan blade on constant rotation with
varying pitch angle and dynamic moves. CPP control mechanism serves
to adjust the angle of pitch propeller (blade angle) with the aim
of producing a variation of thrust (thrust). This mechanism
typically used in aircraft, ships, hovercraft, etc.. The working
principle of CPP control mechanism is by setting or changing the
pitch angle of the propeller. Hydraulic is used to push linkage
mechanism to change pitch angle position.
Fan blade strength testing was done in two ways: static testing
and dynamic testing. Static testing was conducted to determine the
maximum thrust occurs in every corner of his pitch. While the
dynamic testing was conducted to determine the ability of the fan
blade withstand varied styles arising from the rotation and
movement of the fan blade pitch angle changing automatically from 0
to 55, the number of revolutions reaches 1,000,000 rounds or until
the fan blade broke / broken
Figure 9 Control Pitch Propeller (CPP) machine
The purpose of static test is to find out the optimum pitch
angle to produce maximum thrust. Static test was carried out when
the blade was rotated at 1500 rpm for 30 minutes. Thrust was
recorded using load cell. Zero degrees was set when there was no
thrust at all or load cell indicated the minimum value. Static test
thrust force was done by adjusting the pitch angle from 0 to 55
with increment of 5o for every cycle. Figure 10 shows the result of
thrust resulted from static test. The graph shows that the maximum
thrust occur when the pitch angle was set at 35o.. Figure 10.
Thrust force for every pitch angle, blade rotation 1500 rpm.
The purpose of dynamic test is to investigate the effect of
varied resulted thrust to the performance of blade. Dynamic testing
was carried out when the blade was rotated at constant speed of
3000 rpm. The blade angle then rotated on its axial blade axis to
find out the zero reference where there was no trust. Experiment
was carried out by adjusting the pitch angle from 0o to 55o with
increment of 5 degrees. The blade was twisted from 0o to 5o while
it rotated at 3000 rpm for 15 minutes. Thrust resulted was measured
using load cell. Physical check should be done to investigate
damage due to dynamic test after one cycle test completed. One
cycle test mean every 15 minutes running in dynamic test for
increment pitch angle of 5 degrees, hydraulic push and pull
adjusted rod to twist blade from 0o to pitch angle required
automatically. Every cycle was repeated 3 times to get good data.
Second data was taken when the blade was twisted from 0o to 10o and
running in the same speed 3000 rpm for 15 minutes. Test was
repeated until the pitch angle reach 55o.
Experiments conducted over 1 million rounds or until there is
damage to the fan blade. Practically over one million rounds the
blade condition shows no damage and blade remains in good
condition.
4.0 CONCLUSIONFrom the tensile test results, has a polyester
resin matrix tensile stress which does not differ much from the
epoxy resin matrix, the matrix is due to function only as an
adhesive material (bonding). For best results composites have
tensile strength and flexural strength of the best is the direction
of fiber composites with 0 / 90. The blade can withstand and
reliable after over one million rounds on dynamic test. No fiber
pullout after completed the test. Further investigation is needed
to test in the real condition due to environment condition.
Acknowledgement
We would like to appreciate gratefulness to the ministry of high
education for giving research grand. We also would like to
appreciate gratefulness to Politeknik Negeri Semarang especially
department of mechanical engineering who give us opportunity to use
the laboratory to conduct the experiment.
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