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Materials and Design 36 (2012) 75–80
Contents lists available at SciVerse ScienceDirect
Materials and Design
journal homepage: www.elsevier.com/locate/matdes
Hybrid composite laminates reinforced with glass/carbon woven fabrics
for lightweight load bearing structures
Jin Zhang, Khunlavit Chaisombat, Shuai He, Chun H. Wang ⇑
Sir Lawrence Wackett Aerospace Research Centre, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, VIC 3083, Australia
a r t i c l e
i n f o
Article history:
Received 6 September 2011
Accepted 3 November 2011
Available online 12 November 2011
Keywords:
A. Composites
B. Laminates
H. Selection for material properties
a b s t r a c t
Light-weight structure utilising novel design and advanced materials is one of the keys to improving the
fuel efficiency and reducing the environmental burden of automotive vehicles. To ensure the low cost of
applying fibre-reinforced materials in automotive vehicles, it is proposed to selectively incorporate carbon fibres to enhance glass fibre composites along main loading path. This paper investigates the influences of stacking sequence of on the strength of hybrid composites comprising materials with differing
stiffness and strength. Hybrid composite laminates were manufactured using varying ratio of glass
woven fabric and carbon woven fabric in an epoxy matrix. Static tests including tension, compression
and three-point-bending were carried out to composite coupons containing various ratios of carbon
fibres to glass fibres. The results show that hybrid composite laminates with 50% carbon fibre reinforcement provide the best flexural properties when the carbon layers are at the exterior, while the alternating
carbon/glass lay-up provides the highest compressive strength. The tensile strength is insensitive to the
stacking sequence. Analytical solutions are also developed and are shown to provide good correlation
with the experimental data, which allow the optimisation of stacking sequence of hybrid composites
to achieve the maximum strength.
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
The shortage of fossil fuel supply and the new imperative of
environmental sustainability to combat global warming have exerted tremendous pressure on transforming the current materials
design and manufacturing technologies for human transportation
(air, land and sea). Lightweight is rapidly becoming a necessity
for structures, as a result of its less energy consumption from the
vehicles which take into account of this critical issue. While plastic
and composite materials are used in automobiles today, they constitute only approximately 7.5% of total vehicle mass and the applications are generally not for the primary vehicle structure [1].
Important reasons for the growing adoption of polymer matrix
composites [2] are the reduced weight (30–40% lighter than steel
parts of equal strength), part consolidation opportunities, design
flexibility, reduced tooling cost, better damage and corrosion resistance, material anisotropy and improved internal damping, etc.
Although the great advantages of polymer matrix composites
have been recognised by automotive industry, there exist a number
of critical challenges before their wide use in primary automotive
structures. Concerns about high material costs, slow production
rates and recyclability and the auto-industry’s lack of experience
⇑ Corresponding author. Tel.: +61 3 99256115; fax: +61 3 9925 6108.
E-mail address: [email protected] (C.H. Wang).
0261-3069/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.matdes.2011.11.006
with composite materials, are the main problems automakers are
facing currently [1,3,4]. The most popular reinforcements for polymer matrix composites are carbon and glass fibres. It has been estimated that the use of glass fibre reinforced polymer matrix (GFRP)
composites as structural components could yield a 20–35% reduction in vehicle weight; more significantly, the use of carbon fibre
reinforced polymer matrix (CFRP) composites could yield a 40–
60% weight reduction [5]. While fibreglass composites have been
increasingly used to replace steel in automotive industry [6,7],
the adoption rate for carbon fibre composites which are much lighter, stronger and stiffer than glass fibre composites, remains low. The
main reason is the high cost of carbon fibres; that is also the reason
why CFRP composites are only popular in concept and luxury cars
and aerospace vehicles. Different from the aerospace sector, where
additional payload capacity and engine efficiency are the paramount issues, the high-volume production of automotive industry
results in the most important consideration of being cost-effective
that overwrites any technical concerns [8]. Cost reduction continuously to be the number one challenge facing automobile manufacturers while fuel economy and technology transformation are
becoming more important [9].
To further reduce vehicle weight without excessive cost increase, one technique is to incorporate carbon fibre reinforcement
into glass fibre composites and innovatively design by selectively
reinforcing along the main load path [10–12]. Hybrid composites
J. Zhang et al. / Materials and Design 36 (2012) 75–80
2. Experimental procedure
Colan™ E-glass plain weave fabric and Sigmatex™ carbon 2/2
twill weave fabric (T300, 3 K Tow, 199 GSM) were used to reinforce
West system epoxy 105 cured with slow hardener 206. Wet lay-up
was applied to fabricate laminates with five different lay-up
schemes: [C]8, [C2G2]s, [CG3]s, [CGCG]s and [G]8, where C and G denote carbon fibre and glass fibre respectively. The composite laminates were cured at ambient temperature for 24 h before cut into
specimens for mechanical tests. The overall fibre weight fraction of
the composites was approximately 45%. The ASTM D3039-76 [21]
and ASTM D 790 [22] standards were used for tension and threepoint-bending tests; the compression tests were performed using
a NASA short block compression fixture. The thickness of the cured
composite laminates was between 2.5 mm and 3.5 mm. The specimen dimensions were 250 mm 25 mm for tensile and were
100 mm 25 mm for flexural tests. The compression specimens
were grinded to ensure perfectly horizontally parallel top and bottom edges, with the dimension of 52 mm 25 mm. The optical
micrographs were taken from a Leica EZ4D and a DP 71 optical
microscope.
3. Results and discussion
3.1. Hybrid composites under tensile and compressive loading
With the variation of composition, the density for five types of
composites varied from 1.508 g/cm3 for the plain glass fibre composite [G]8 to 1.460 g/cm3, 1.327 g/cm3, 1.316 g/cm3 and 1.237 g/cm3
for the [CG3]s, [C2G2]s, [CGCG]s and [C]8 composites, respectively.
The addition of carbon fibre reinforcement reduced the density of
the composites. The tensile and compressive stress–strain curves
500
Tensile Stress (MPa)
are composed of more than one type of reinforcement and they can
be classified into interply or laminated hybrid, intraply or tow
-by-tow hybrid, intimately mixed hybrid, and other types of mixtures. Some of the influential factors that affect the composite
mechanical performance from the reinforcement include the
length of fibre, fibre orientation, fibre shape and fibre material
[13,14]. Since the mechanical properties of glass and carbon fibres,
and the interfacial properties between reinforcement and matrix
differ greatly, the hybridisation effects would vary too for the hybrid composites [15–17]. A comprehensive review on the mechanical properties of hybrid fibre reinforced plastics especially on
glass/carbon hybrid composites showed that the longitudinal tensile moduli are generally in good agreement with the rule of mixture, which is due to the strain compatibility through the thickness
of a hybrid material [18]. The review also showed that the shape of
the stress–strain curves for hybrid composites varies with the different type of fibres and resins used, the overall fibre fraction and
the orientation of the reinforcement in the material. Positive hybrid effect was observed in flexure tests of specimens with high
glass versus carbon fibre ratio [19]; however, the compression
and fracture energy of glass/carbon epoxy matrix composites
exhibited negative hybrid effect [18]. In a recent study, the tensile
and compressive loading cases on hybrid glass/carbon fabric composites have been investigated and the main observation of this
work is that by placing glass fabric layers in the exterior and carbon fabric layers in the interior, higher tensile strength and ultimate tensile strain were obtained [20].
In the present study, E-glass and carbon fibre woven fabrics
with epoxy resin matrix have been used for fabricating hybrid laminates. Different glass/carbon ratios and stacking sequences were
investigated against the tensile, compressive and flexural responses of hybrid composite laminates.
1:
2:
3:
4:
5:
a
1
400
300
2
[C]8
[C2G2]s
[CG3]s
[C/G/C/G]s
[G]8
4
5
3
200
100
0
0.0
0.5
1.0
1.5
2.0
Tensile Strain (%)
1:
2:
3:
4:
5:
500
Compressive Stress (MPa)
76
b
400
300
1
200
2
4
3
5
100
0
0.0
[C]8
[C2G2]s
[CG3]s
[C/G/C/G]s
[G]8
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Compressive Strain (%)
Fig. 1. Tensile and compressive stress–strain curves for different composite
laminates.
for all five types of composite laminates are shown in Fig. 1 and
the calculated mechanical property data are included in Table 1.
As expected, the [C]8 composite had the highest tensile and compressive strength and the [G]8 composite had the lowest tensile
and compressive strength, where the average tensile and compressive strength of plain glass fibre composites account for almost 50%
of the plain carbon fibre composites for both tension and compression loading cases. The compressive strength of [C]8 was 38% lower
than its tensile strength and the compressive strength of [G]8 was
42% lower than its tensile strength. At the same glass/carbon fibre
ratio, [C2G2]s and [C/G/C/G]s showed similar tensile strength;
however, higher compressive strength and strain were found for
the [C/G/C/G]s than the [C2G2]s. With the addition of 25% of carbon
fibres in the exterior layers, [CG3]s exhibited only slight improvement in both tensile and compressive strength than plain glass
composite [G]8. The compressive strain resulted from the alternating lay-up scheme ([CGCG]s) showed the highest value above all
other composites. The enhanced compression strength for the
alternating stacking sequence may be caused by the bridging effect
of the carbon fibre layer between the failed glass fibre layers.
Kretsis has concluded that in hybrid composites, the weakest
low-elongation fibres break first to form cracks that are ‘bridged’
by the surrounding high-elongation composite, thus allowing the
stronger low-elongation fibres to reach their ultimate strength
[18]. A similar explanation has also been given by Manders who
pointed out that the hybrid effect arises from a failure to realise
the full potential strength of the fibres in all-carbon fibre composites, rather than from an enhancement of their strength in the
hybrids [23].
77
J. Zhang et al. / Materials and Design 36 (2012) 75–80
Table 1
Mechanical properties of composite laminates under tensile and compressive loading.
Lay-up
scheme
Tensile strength
(MPa)
Ultimate tensile
strain (%)
Young’s modulus for
tension (GPa)
Compression
strength (MPa)
Ultimate compressive
strain (%)
Young’s modulus for
compression (GPa)
[C]8
[C2G2]s
[CG3]s
[C/G/C/G]s
[G]8
420
260
206
263
200
1.07
1.18
1.41
1.40
1.87
38.39
22.04
18.09
22.27
11.01
260
171
189
217
117
3.06
2.63
3.01
3.13
2.76
10.97
7.40
7.72
8.22
5.14
(±0.13)
(±0.06)
(±0.14)
(±0.38)
(±0.29)
(±2.43)
(±1.50)
(±0.54)
(±0.84)
(±2.11)
The linear rule of mixture (ROM) was used for calculating the
tensile and compressive strength. Denoting the carbon fibre ratio
of all fibre reinforcement is a, the Young’s modulus can be expressed using the simple rule of mixtures as:
E ¼ aEC þ ð1 aÞEG
ð1Þ
where E denotes the modulus of hybrid composite, EC denotes the
modulus of carbon fibre composite and EG denotes the modulus of
glass fibre composite. So the stress (r) of the hybrid composite
can be expressed as
r ¼ ðEC tC þ EG tG Þec =ðtC þ tG Þ
ð2Þ
Assuming a equals to the percentage of the thickness of carbon
layers (tC) in the whole laminate (tC + tG) and the composite fails
when the elongation of laminates reaches ec. However, in real case,
the glass fibres can still carry load until the ultimate strain of glass
fibre composite is reached. Therefore the maximum stress of hybrid composites is
rmax ¼ max ½ec ðEC tC þ EG tG Þ=ðtC þ tG Þ; EG tG eG =ðtC þ tG Þ
ð3Þ
As it can be seen from Fig. 2, the tensile strength results agreed
well with analytical results; however, the compressive strength
exhibited a negative hybridisation effect, where the hybridisation
effect is shown by the deviation from the ROM behaviour. Stevanovic et al. found similar results when they investigated the tensile
properties of unidirectional carbon fibric /non wovon glass mat/
polyester resin hybrid composite laminates. The tensile moduli of
their tested composites agree with values calculated by the ROM
[19]. The ROM could not demonstrate the difference in the compressive strength of [C2G2]s and [CGCG]s composites, due to the
same carbon/glass fibre ratio.
Maximum Stress (MPa)
500
σT-experimental
(±12)
(±38)
(±33)
(±42)
(±8)
eðzÞ ¼ jz
ð4Þ
where z denotes the coordinate along the thickness direction
(Fig. 4). Different fibre reinforced composite plies can exhibit significantly different failure strains. For instance, unidirectional glass/
polyester laminae can reach an axial failure strain of approximately
500
1:
2:
3:
4:
5:
1
400
2
4
300
3
[C]8
[C2G2]s
[CG3]s
[C/G/C/G]s
[G]8
5
200
100
0
0.0
σC-experimental
0.5
1.0
1.5
2.0
2.5
3.0
Flexural Strain (%)
σC-analytical
300
(±0.18)
(±0.83)
(±1.59)
(±1.75)
(±0.17)
The flexural stress–strain curves for all five types of composite
laminates are shown in Fig. 3 and the calculated mechanical property data are included in Table 2. As expected, the [C]8 composite
had the highest flexural strength and lowest flexural strain, which
is the opposite case to the [G]8 composite. Placing two carbon layers at the exterior effectively increased the flexural strength, as
shown in the stress–strain curve for the [C2G2]s composite. The
flexural strength of the [C2G2]s was 406 MPa, accounting for 89%
of the plain carbon fibre laminate [C]8. By placing the high stiffness
carbon fibre away from the neutral axis and the low stiffness glass
fibre at the neutral axis, the flexural modulus is enhanced significantly, which is also proved by other researchers work [24].
Based on the plane section assumption, the strain distribution
in the laminate can be expressed in terms of the curvature j, with
the origin of the coordinate being at the mid plane of the composite laminate,
σT-analytical
400
(±0.21)
(±0.30)
(±0.20)
(±0.21)
(±0.20)
3.2. Hybrid composites under flexural loading
Flexural Stress (MPa)
(±57)
(±7)
(±9)
(±11)
(±3)
Fig. 3. Flexural stress–strain curves for different composite laminates.
200
[CGCG]s
[C2G2]s
100
0
0
20
40
60
Table 2
Mechanical properties of composite laminates under flexural loading.
80
100
Carbon Fibre Ratio (%)
Fig. 2. Tensile and compressive strength of composite laminates affected by the
carbon fibre ratios in the reinforcement (both experimental and analytical results).
rT is the tensile strength and rC is the compressive strength.
Lay-up
scheme
Flexural strength
(MPa)
Ultimate flexural
strain (%)
Flexural modulus
(GPa)
[C]8
[C2G2]s
[CG3]s
[C/G/C/G]s
[G]8
455
406
339
348
218
1.69
1.68
1.78
1.81
3.00
29.03
27.31
21.98
22.47
11.12
(±35)
(±17)
(±15)
(±9)
(±9)
(±0.04)
(±0.04)
(±0.05)
(±0.08)
(±0.10)
(±2.09)
(±1.19)
(±0.91)
(±0.70)
(±0.46)
78
J. Zhang et al. / Materials and Design 36 (2012) 75–80
jmax ¼ min
ec ðzi Þ et ðzi Þ
;
zi
zi
;
i ¼ 1; 2; 3 . . . N
ð5Þ
where ec(zi) denotes the strain of the ith ply under compression and
et(zi) denotes the stress of the ith ply under tension. It is clear that
maximum deformation (curvature) occurs when plies with the
highest failure strain are placed close to the surface, far removed
from the neutral axis.
The bending moment of a beam with rectangular section is given by,
Fig. 4. The rectangular beam under bending.
M¼
Z
t=2
rx ðzÞzBdz ¼ j
t=2
Maximum Stress (MPa)
[C2G2]s
400
300
[CGCG]s
M¼
200
σF-experimental
σF-analytical
100
0
0
20
t=2
zEðzÞBdz
ð6Þ
t=2
where t is the thickness of the beam, B is the width of the structure,
rx(z) is the stress either in compression or tension and E(z) denotes
the Young’s modulus of the material at coordinate z. It can be seen
from Eq. (6) that the maximum bending moment of a hybrid laminate depends on through-thickness distribution of the strain-tofailure and lamina stiffness. Considering a symmetric laminate with
eight plies, the moment is
600
500
Z
40
60
80
100
Carbon Fibre Ratio (%)
Fig. 5. Flexural strength of composite laminates affected by the carbon fibre ratios
in the reinforcement (both experimental and analytical results).
N
BX
ðt2 t2i1 Þ½EðiÞT þ EðiÞC j
2 i¼1 i
where ti denotes the locations of the ith ply of a laminate containing
a total of 2N plies in a symmetric lay-up. Because for a rectangular
section, the maximum flexural stress can be written as
rmax ¼ M=S ¼ M=ðBt2 =6Þ ¼ 6M=Bt2
a
N
X
t2i t2i1 ½EðiÞT þ EðiÞC j
ð9Þ
i¼1
If 50% of the reinforcement is carbon fibre, the maximum flexural stress can be obtained when two carbon fibre composite layers
are located at the exterior of the laminate. Both the experimental
and analytical flexural strength data are shown in Fig. 5. The analytical solutions were able to simulate the experimental trend
influenced by hybrid composition and stacking sequence; however, their calculated results were higher than the experimental
data due to the shear stresses presented in the specimens which
b
d
ð8Þ
where S is the elastic section modulus. The maximum flexural stress
can be determined as
rmax ¼ ð3=t2 Þ
2%, the strain-to-failure for type I carbon/epoxy unidirectional laminae is approximately 0.5% [25], and the natural fibre/epoxy composite strain can reach 5.2% when jute is used as reinforcement
[26]. So for a hybrid composite laminate under pure bending load,
the maximum bending moment it can carry corresponds to the load
when a certain ply in the laminate reaches its failure strain. Due to
the potentially very large difference in failure strains of different
types of composite materials, critical location may not always be
the surface ply. The maximum curvature at failure of the laminate is
ð7Þ
c
e
Fig. 6. Optical micrographs of failed composite laminates under tensile loading. (a) [C]8, (b) [C2G2]s, (c) [CG3]s, (d) [CGCG]s and (e) [G]8. (b) and (c) show the edge views of
failed tensile specimens and the rest show the facture surfaces.
79
J. Zhang et al. / Materials and Design 36 (2012) 75–80
a
b
d
c
e
Fig. 7. Optical micrographs of failed composite laminates under compressive loading. (a) [C]8, (b) [C2G2]s, (c) [CG3]s, (d) [CGCG]s and (e) [G]8.
a
b
d
c
e
Fig. 8. Optical micrographs of failed composite laminates under flexural loading. (a) [C]8, (b) [C2G2]s, (c) [CG3]s, (d) [CGCG]s and (e) [G]8.
caused additional displacements and led to reduced modulus. For
the low span-to-depth ratios and high modulus materials, these
shear stresses are more significant [18,19].
3.3. Failure modes of hybrid composite laminates
The failed composite specimens were investigated under optical
microscopes. Fig. 5a, d and e presents the tensile fracture surface of
the [C]8, [CGCG]s and [G]8 composites. The fibre pull-outs of the
plain glass fibre composite were more significant than the plain
carbon fibre composite [C]8 and the alternating carbon/glass fibre
laid-up composites [CGCG]s. In comparison, the composites with
one or two carbon fibre layers at the exterior did not break into
two halves, with glass fibres bridging the ruptured carbon surface
layers (Fig. 6b and c shows the edge view of the tensile specimens).
The optical micrographs in Fig. 7 display the compression failure of
different types of composites. It can be seen that the carbon fibre
layers failed with a transverse catastrophic mode, wherever the
glass fibre layer failed with the typical kinking–slitting mode. By
applying the alternating lay-up scheme, the compression failure
was effectively suppressed. Fig. 8 presents the cross-sections of
the failed flexural specimens along the central line of span. The
plain carbon fibre composite [C]8 exhibited brittle failure, where
the specimen broke through all layers with abundant carbon fibre
rupture. The other four types of composite laminates showed more
matrix fracture other than reinforcement failure, in comparison
with the compression failure modes. With the hybridisation of
the reinforcement, the brittle and catastrophic failure mode of
the all carbon fibre composite is avoided. It can be concluded that
improvement in the balance of stiffness and toughness in composite laminates can be realised through hybridisation [24,27].
4. Conclusion
Five types of composite laminates, i.e. [C]8, [C2G2]s, [CG3]s,
[CGCG]s and [G]8 composites, were investigated under static load-
80
J. Zhang et al. / Materials and Design 36 (2012) 75–80
ing under tension, compression and three-point-bending. To effectively improve the tensile, compressive and flexural strength of the
plain glass fibre composite, glass/carbon (50:50) fibre reinforcement was used either by placing the carbon layers at the exterior
or by placing different fibre types alternatively. With the same hybrid composition, the stacking sequence did not show noticeable
influence on the tensile properties but affected the flexural and
compressive properties significantly. The current composite system exhibited more matrix failure under flexural loading and more
reinforcement failure under compressive loading.
Acknowledgement
This work was supported by the ‘‘Lightweight Modular Vehicle
Platform’’ project of Australian Cooperative Research Centre for
Advanced Automotive Technology (Auto CRC).
References
[1] Cramer DR, Taggart DF. Design and manufacture of an affordable advancedcomposite automotive body structure. In: The 19th international battery,
hybrid and fuel cell electric vehicle symposium & exhibition; 2002.
[2] Plastics in automotive markets technology roadmap: a new vision for the road
ahead. The plastic division of the American Chemistry Council (ACC); 2009.
[3] Beardmore P, Johnson CF. The potential for composites in structural
automotive applications. Compos Sci Technol 1986;26:251–81.
[4] Thilagavathi G, Pradeep E, Kannaian T, Sasikala L. Development of natural fiber
nonwovens for application as car interiors for noise control. J Ind Text
2010;39:267–78.
[5] Das S. The cost of automotive polymer composites: a review and assessment of
DOE’s lightweight materials composites research. Oak Ridge National
Laboratory; 2001. p. 1.
[6] Al-Qureshi HA. Automobile leaf springs from composite materials. J Mater
Process Technol 2001;118:58–61.
[7] Hosseinzadeh R, Shokrieh MM, Lessard LB. Parametric study of automotive
composite bumper beams subjected to low-velocity impacts. Compos Struct
2005;68:419–27.
[8] Tucker N, Lindsey K. An introduction to automotive composites. Rapra
Technology Limited; 2002.
[9] Jacob A. Automotive composites – the road ahead. Reinf Plast 2001;45:28–32.
[10] Mahdi E, Hamouda AMS, Sahari BB, Khalid YA. Effect of hybridisation on
crushing behaviour of carbon/glass fibre/epoxy circular-cylindrical shells. J
Mater Process Technol 2003;132:49–57.
[11] Hosur MV, Adbullah M, Jeelani S. Studies on the low-velocity impact response
of woven hybrid composites. Compos Struct 2005;67:253–62.
[12] Nordin H, Täljsten B. Testing of hybrid FRP composite beams in bending.
Composites Part B 2004;35:27–33.
[13] Kaw AK. Mechanics of composite materials. 2nd ed. Tampa: CRC Press, Taylor
& Francis Group; 2005.
[14] Grujicic M, Pandurangan B, Koudela KL, Cheeseman BA. A computational
analysis of the ballistic performance of light-weight hybrid composite armors.
Appl Surf Sci 2006;253:730–45.
[15] Fu SY, Mai YW, Lauke B, Yue CY. Synergistic effect on the fracture toughness of
hybrid short glass fiber and short carbon fiber reinforced polypropylene
composites. Mater Sci Eng A 2002;323:326–35.
[16] Giancapro JW, Papakonstantinou CG, Balagura PN. Flexural response of
inorganic hybrid composites with E-glass and carbon fibers. J Eng Mater
Technol 2010;132:1–8.
[17] Hwang S, Mao C. Failure of delaminated interply hybrid composite plates
under compression. Compos Sci Technol 2001;61:1513–27.
[18] Kretsis G. A review of the tensile, compressive, flexural and shear properties of
hybrid fibre-reinforced plastics. Composites 1987;18:13–23.
[19] Stevanovic M, Stecenko T. Mechanical behaviour of carbon and glass hybrid
fibre reinforced polyester composites. J Mater Sci 1992;27:941–6.
[20] Pandya KS, Veerraju C, Naik NK. Hybrid composites made of carbon and glass
woven fabrics under quasi-static loading. Mater Des 2011;32:4094–9.
[21] ASTM International. Standard test methods for tensile properties of fiber-resin
composites. ASTM D 3039-76. Philadelphia (PA): Annual book of ASTM
standards; 1989.
[22] ASTM International. Standard test methods for flexural properties of
unreinforced and reinforced plastics and electrical insulating materials.
ASTM D 790-84. West Conshohockon (PA): Annual book of ASTM Standards;
1990.
[23] Manders PW. PhD thesis. The strength of mixed fibre composites. University of
Surrey, 1979.
[24] Naik NK, Ramasimha R, Arya H, Prabhu SV, ShamaRao N. Impact response and
damage tolerance characteristics of glass–carbon/epoxy hybrid composite
plates. Composites Part B 2001;32(7):565–74.
[25] Hull D, Clyne TW. An introduction to composite materials. In: Clark DR, Suresh
S, Ward FRS IM, editors. 2nd ed. Cambridge University Press; 1996.
[26] Hakim S, Sultan Aj. Energy systems and crushing behaviour of fiber reinforced
composite materials. World Acad Sci Eng Technol 2011;74:280–6.
[27] Manders PW, Bader MG. The strength of hybrid glass/carbon fibre composites.
J Mater Sci 1981;16(8):2233–45.
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