World Journal of Engineering
GENERALIZED GEOMETRIC MODEL OF 3D WOVEN PREFORMS FROM SPUN
YARNS
Abdel-Fattah M. Seyam and Mehmet E. Ince
College of Textiles, North Carolina State University, Raleigh, NC 27695
The shortage in the petroleum and the environmental
Literature review disclosed that the existing models are
concerns prompted researchers to conduct research on
not comprehensive and deal with limited number of
composites from natural fibers and resins. Natural fibers
weaves. This lack of existing generalized model has
are short staple and must be twisted together to form
prompted us to undertake this research. We developed a
yarns. The yarns and the 3D woven preform construction
generalized model for composites from 3D woven
parameters from staple fibers assume totally different
preforms made from spun yarns that are made from short
geometries compared to continuous filament yarns that
synthetics and/or natural fibers. Yarns from natural
are traditionally used in preforms for composites. The
fibers such as cotton, wool, jute, hemp, sisal, kenaf, and
goal of this research is to develop a general geometric
flax established themselves in composite applications
model of three-dimensional (3D) woven preforms from
due to their sustainability and they are friendly to the
spun yarns to predict fiber volume fraction of the
environment [5].
structure constituents in terms of yarns and preform
The model predicts the fiber volume fraction, material
construction parameters including weave. Numerical
requirements, and composite thickness in terms of the
solutions are provided to demonstrate how the fiber
constituent yarns’ parameters, and weave design and
volume fraction, which influences the mechanical
takes into account non-jammed and jammed (fully
performance of the final composite, is affected by the
orthogonal) structures. This paper addresses the effect of
model parameters with emphasis in weave structure. The
weave and yarn linear density on the constituents and
target of the model is to obtain desired level of fiber
total fiber volume fractions.
volume fractions and hence achieve predetermined
properties of the final composite.
3D Orthogonal Woven Fabric Preform
Three dimensional woven fabrics (Figure 1) consist of
Introduction
multiple layers of x- and y-yarns and several sets of zThe share of fiber-based composite materials as an
yarn (binding yarns) depending on weave design.
alternative to metal in any industrial area is increasing
due to their high specific strength-stiffness, corrosion
resistance, energy absorbance capacity, and fatigue life.
Through the thickness mechanical properties of
composites such as interlaminar shear strength, damage
tolerance, and impact resistance have been improved
with the advance of 3D woven preforms [1, 2].
The internal geometry (weave interlacing, thread density,
thread size, cross-section shape of the threads, etc.) of the
preform influence the composite performance since it
determines the shape and size of the resin flow channels.
a
b
Internal geometry also directly affects the composite
: X-yarn
: Y-yarn
: Z – yarn
mechanical properties dictated by the amount of fiber in
Figure
1
Isometric
view
of:
(a)
3D
orthogonal
(jammed)
a given direction [3]. Therefore, the internal geometry of
plain woven preform and (b) 3D non-jammed plain
the structures should be evaluated thoroughly to produce
woven preform
a composite product of fully saturated, targeted stiffness
and strength properties for specific directions [4].
Assumptions
To simplify the development of the geometrical
relationships, we assumed the following:
1. Yarns are uniform cylinders (yarn cross-section is
circular)
2. The yarns have uniform packing factor
3. The yarns are completely flexible and incompressible
4. The yarn spacing is uniformly distributed along and
across the preform
Geometric Model
Geometrical models permit accurate prediction of the
fiber volume fraction before preform manufacturing and
enable foreseeing composite manufacturing performance
as well as model mechanical properties (stiffness and
strength) of the composite end product. Predicting both
fiber volume fraction and the internal geometry with
given yarn and weave parameters also enable designing
structures for specific application.
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World Journal of Engineering
Spun yarns are composed of short fibers that are held
A generalized geometric model was developed to predict
fiber volume fraction for 3D woven preform fabrics
together by twisting them during processing. Therefore,
from spun yarns. The model is not constricted to any
the cross-sectional shape of spun yarn tends to be
specific construction and considers jammed situation as
circular due to the distributed lateral forces on yarn
a special case. The effects of construction parameters,
surface (caused by the twist) experienced by the fibers in
especially weave, on fiber volume fraction was clearly
the yarn structure.
demonstrated. The z-yarn path assumed in this study is
more realistic as compared to previous studies.
Results
The numerical results calculated from the model
revealed that for non-jammed structure as linear density
F %
8
of all constituent yarns increase, then fiber volume
6.64
6.64
7
6
fraction increases at constant yarn spacing. On the other
5.11
5.11
5
4.34
4.34
hand, linear density has no effect on fiber volume
4
3
fraction for jammed structures as shown in Figure 2 (a),
2
1
and (b).
fz
0
Ffx%
20
18
16
14
12
10
8
6
4
2
0
Ffz%
Ffy%
Plain
M2 =1
2x2 Filling Rib
M2 =1
2x2 Basket
M2 =2
2x2 R.H. Twill
M2 =2
4x4 R.H. Twill
M2 =4
8-H. Sateen
M2 =4
Ffxyz%
17.36
a
11.26
7.15
4.63
2.26
Ffx%
6.64
5.06
2.53
1.13 1.24
ρℓxyz = 200
3.68
40
35
30
25
20
15
10
5
0
3.58
ρℓxyz = 1000
ρℓxyz = 2000
a
Ffx%
Ffz%
Ffxyz%
26.04
24.26
21.35
10.67
10.67
3.30
Plain
M2 =1
38.46
37.27
35.32
Ffxyz%
Ffz%
Ffy%
Ffy%
10.67
2.34
2x2 R.H. Twill
M2 =2
1.75
8-H. Sateen
M2 =4
35
28.43
30
28.43
b
28.43
25
20
15
10
5
0
13.12
10.21
13.12
10.21
5.10
ρℓxyz= 200
Figure 3 Effect of weave on fiber volume fraction; (a) zfiber volume fraction for non-jammed, (b) for jammed
case (M2: x-yarn weave factor)
13.12
10.21
5.10
ρℓxyz = 1000
5.10
Acknowledgement
We would like to thank University of Gaziantep, Turkey
for providing scholarship for Mr. Ince and the state of
North Carolina and National Textile Center for funding
the project.
ρℓxyz= 2000
b
Figure 2 Effect of yarn linear density on fiber volume
fraction; (a) non-jammed and (b) jammed structures
: Linear density of related yarn material (g/km)
: Fiber volume fraction of related yarn (%)
: Total fiber volume fraction (%)
For given x-, y-, z-yarns and x-, y-, and z-yarn spacing,
only z-yarn fiber volume fraction is affected by the
weave in case of non-jammed structures (Figure 3(a))
due to change in number of z-yarn interlacing. While in
jammed structures, for given x-, y-, z-yarns and y- and zyarn spacing, the x- and z-yarn fiber volume fraction are
affected by weave (Figure 3(b)). The x-yarn spacing
reduces as the weave float gets longer a matter that
increases the number of x-yarn in the structure and hence
fiber volume fraction increases.
References
1. Quinn, J., McIlhagger, R., & McIlhagger, A. T.
(2003). A
modified system for design and analysis of 3D woven preforms.
Composites Part A: applied science and manufacturing , 503-509.
2. Mohamed, M. H. (1990). Three-dimensional Textiles. American
Scientist , 78, 530-541.
3. Seyam, A. M., Taylor, D., Mohamed, M., Powell, N., & Meng, J.
(2011). 3D Woven Composites for Automotive Applications:
Structure Parameters/Impact Energy Relationships. World Journal of
Engineering
4. Miravete, A. (2000). 3-D textile reinforcements in composite
materials. In F. K. Ko, 3-D textile reinforcements in composite
materials (pp. 9-42). Boca Raton: CRC Press.
5. Seyam, A. M., Laney, M. L., Clapp, T. G., & Mohamed, M. H.
(2010). Three-Dimensional Woven Composites from Natural Fibers
and Resins. 39th Textile Research Symposium. New Delhi: Indian
Institute of Textile Technology.
Conclusion
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