Influence of 3D Warp Interlock Fabric Parameters on
Final Geometry
F. BOUSSU, C. CHEVALIER, C. KERISIT and D. COUTELLIER
ABSTRACT
The exact geometry of 3D warp interlock fabric during production is highly
dependent on the weaving process. Several fabric parameters as the number of layers,
the weave diagram of linking warp yarns and the end and pick densities can influence
the final geometry. Several fabrics have been produced on the same dobby weaving
machine using para-aramid yarns with different warp and weft densities. Thanks to
these observations, differences between final geometries of 3D warp interlock fabric
as the different position of yarn insertion and the cross-section shapes have been
revealed.
INTRODUCTION
One of the recent trend of composite material design aims at reducing the labour costs,
and especially those induce by the handling of the fibrous reinforcement. One of the
existing solutions consists in the use of fibrous reinforcement directly produced in one
step into the final required 3D shape. Thus, the handling of this 3D shape fibrous
reinforcement is faster due to its easier fitting inside the mould for resin infusion in
thermoset parts and thermo-compression for thermo-plastic parts. 3D shape fibrous
reinforcement can be obtained by various technologies.
_____________
François Boussu, Ecole Nationale Supérieure des Arts et Industries Techniques (ENSAIT), 2
Allée Louise et Victor Champier, 59100 Roubaix, France
Caroline Chevalier, Christophe Kerisit, French-German Research Institute of Saint-Louis (ISL),
5 rue du général Cassagnou, BP 70034, 68301 Saint-Louis Cedex, FRANCE
Daniel Coutellier, LAMIH UMR CNRS 8201 University of Valenciennes, UVHC Campus Mont
Houy, 59313 Valenciennes Cedex 9, FRANCE
Among all the existing 3D shape solutions, the 3D warp interlock fabric weaving
affords to obtain multi-layer woven fabrics linked together by linking yarns driven by
different weave diagrams to obtain the required thickness. 3D warp interlock fabrics
technology seems to be well known and used in several applications [1] [2].
For instance T shape, H shape X shape or I Shape can be obtained on adapted weaving
loom to provide 3D shape fibrous reinforcement for composite material, and
especially based on carbon yarns for aeronautical applications [3]. Depending on the
required dimensions as regard the 3D shape woven preform in Pi cross-section,
different architectures allow to reach the required height and fabric thickness [4] [5].
Recently, by combining the tubular weaving technic with crenel and unbinding
weaving tips, 3D shape woven fabric, including thermoplastic yarns, has also been
designed to provide new fibrous reinforcement solution of composite material for
railway applications [6].
Based on experimental characterization of 3D woven composites, it has been observed
that their mechanical properties and associated failure mechanisms appear relatively
linked to their geometry, according to detailed observations of the fabric [7]. One of
the most interesting features of 3D warp interlock fabric remains the modularity of
their architectures and the relative accurate control of the yarn’s evolution in the
structure leading to safe prediction of mechanical properties [8].
On the contrary, few studies have been conducted to understand the distribution of all
the yarns during the weaving process leading to their final internal geometry. To fill
the gap, we have attempted to reproduce the final geometry of 2D fabrics by
simulation of the kinematic of the weaving process [9] [10] including several
hypothesis. Simple models of material behaviour and geometry of the yarn have
allowed us to reproduce the modification of its cross-section shape due to dynamic
motions of the weaving reed during the beating-up and high speed vertical motion of
heddles. Results of these simulations have been compared with real 3D warp interlock
fabrics for only fundamental weave diagrams as: plain, twill and satin weaves.
Additionally, in the research work of Nauman [11] we have also highlighted the
influence of the weaving loom parameters on the final geometry of 3D warp interlock
fabric produced with carbon yarns. Considering the same weaving loom and the same
type of interlock architecture as an Interlock Orthogonal with binding yarns linking
layer to layer but with different surface weave diagrams and number of layers, it has
been demonstrated that the position of warp yarns inside the weaving reed have led to
modify the cross section shape of carbon warp yarns as well as their distribution as
inclined column inside the 3D fabrics [12]. At a meso-scopic scale, the cross section
shape of the muli-filaments yarn is characterized both by its initial structure and its
path inside the woven structure due to the different motions or yarns and mechanical
forces applied during the weaving process as the warp yarns shedding, the weft yarn
insertion and the weft yarns beating-up at the edge of the fabric forming line on the
weaving loom [13].
In order to investigate the modelling and simulation of the weaving of 3D warp
interlock fabrics, an experimental approach is first needed based on the same weaving
loom and the same type of yarns. Thus, the main objective of this research consists in
checking the influence of weaving process parameters on the final geometry of 3D
warp interlock fabric. To conduct this research, end and pick densities will be
considered as variables and their different values will be modified in order to check
their global influence not only on the final geometry but also on the resulted weight
per surface and fabric thickness.
EXPERIMENTAL RESULTS
To better understand their properties, we have produced 3D warp interlock fabric
based on the same weave architecture including binding and surface warp yarns [14].
The general definition of this architecture represented in Figure 1, which is entirely
described in our research work [15], is:
3D warp interlock O - L 1-2-7 {plain weave}{1 12 - 2 11- 3 10- 4 9- 5 8 – 6 7 - # - #}
– Surface {plain weave}{15 16 - # - # - # - # - # - 13 14 - #}.
This 3D warp interlock fabric is then represented in Figure 1, with all the warp yarns
represented in blue colour and the weft yarns in grey colour. The evolution of warp
yarn are represented both on a 2D view (Figure 1 - left), corresponding to the crosssection of weft yarns, and also on a 3D view (Figure 1 - right).
Figure 1. (left) Evolution of the 1st binding warp yarn in the cross-section view of weft yarns and
3D view (right) of the 3D warp interlock O - L 1-2-7 {plain weave}{1 12 - 2 11- 3 10- 4 9- 5 8 – 6 7 - #
- #} – Surface {plain weave}{15 16 - # - # - # - # - # - 13 14 - #}.
Taking into account this architecture, four different 3D warp interlock fabrics O -L 12-7 have been designed with the same para-aramid 1680 dTex yield for warp and weft
yarns and with the following end and pick densities values:
• Fabric 1: 18 ends/cm - 80 picks/cm
• Fabric 2: 30 ends/cm - 56 picks/cm
• Fabric 3: 42 ends/cm - 42 picks/cm
• Fabric 4: 60 ends/cm – 37 picks/cm
Pictures on the surface of these produced fabrics have been taken just before being
impregnated at very low pressure with epoxy resin in order to fix all the yarns without
modifying their positions inside the 3D woven architecture. Thus, by cutting the
impregnated fabrics into thin slices both in the two fabric directions, different crosssection views of these 3D warp interlock fabrics have been obtained to observe the
evolution of the warp and weft yarns path inside the 3D fabric, as represented in
Figure 2 and Figure 3.
Figure 2. Top view and cross section view for warp and weft yarns of the 3D warp interlock
fabric O -L 1-2-7 with (left – Fabric 1) 18 ends/cm – 80 picks/cm and (right – Fabric 2) 30 ends/cm – 56
picks/cm.
Figure 3. Top view and cross section view for warp and weft yarns of the 3D warp interlock
fabric O -L 1-2-7 with (left – Fabric 3) 42 ends/cm – 42 picks/cm and (right – Fabric 4) 60 ends/cm – 37
picks/cm
Considering the warp yarns cross-section views of the four fabrics, as represented in
Figure 2 and Figure 3, we have observed that the increase of the end density inside the
same fabric architecture reduces the space between yarns and leads to different yarn
cross section shapes as flatly lenticular (Fabric 1: 18 ends/cm), to elliptic (Fabric 2: 30
ends/cm and Fabric 3: 42 ends/cm) and till rectangular shape (Fabric 4: 60 ends/cm)
(TABLE I).
TABLE I. REPRESENTATION OF WARP YARNS CROSS-SECTION VIEWS OF THE 3D
WARP INTERLOCK O - L 1-2-7 {PLAIN WEAVE}{1 12 - 2 11- 3 10- 4 9- 5 8 – 6 7 - # - #} –
SURFACE {PLAIN WEAVE}{15 16 - # - # - # - # - # - 13 14 - #} WITH DIFFERENT END
DENSITIES.
Fabric
1:
ends/cm
18 Fabric
2:
ends/cm
30 Fabric
ends/cm
3:
42 Fabric
4:
ends/cm
60
Higher compaction is applied in the weft direction on the warp yarns while keeping
the same fabric thickness. Thus, this increase of compaction in the weft direction,
leads to higher end density values, which directly influence the modification of weft
yarns path inside the same 3D warp interlock fabric architecture. In Fabric1, the
lowest end density value (18 ends/cm) but the highest pick density value (80
picks/cm), the weft yarns are linearly inserted inside the shed and pushed with the
weaving reed on the fabric forming line with higher pressure. As they need the
sufficient space to be inserted inside the fabric they find more available space in the
fabric thickness direction and then follow the warp yarns location given by their up
and down position corresponding to the weave diagram of the 3D warp interlock
fabric architecture. On the contrary, in Fabric 4, the highest warp yarns density value
(60 ends/cm) with the lowest pick density value (37 picks/cm), weft yarns couldn’t get
more space in the fabric thickness direction and then stay in their initial filling position
which can be assumed is quite linear.
By the same, taking into account the influence of the pick density increase (TABLE
II), with the same 3D warp interlock fabric architecture, on the weft yarns crosssection evolution and on the warp yarns path inside the fabric; observations lead to
similar phenomenon as in the warp direction.
In Fabric 1, the highest pick density value (80 picks/cm) with the lowest end density
value (18 ends/cm), the cross-section shapes of weft yarns appear quite rectangular
and the warp yarns path quite linear. On the contrary, in Fabric 4, the lowest pick
density value (37 picks/cm) and the highest end density value (60 ends/cm), the crosssection shapes of weft yarns seem to be quite flatly elliptic and the warp yarns path
highly undulated.
TABLE II. REPRESENTATION OF WEFT YARNS CROSS-SECTION VIEWS OF THE 3D
WARP INTERLOCK O - L 1-2-7 {PLAIN WEAVE}{1 12 - 2 11- 3 10- 4 9- 5 8 – 6 7 - # - #} –
SURFACE {PLAIN WEAVE}{15 16 - # - # - # - # - # - 13 14 - #} WITH DIFFERENT PICK
DENSITIES.
Fabric
1:
picks/cm
80 Fabric
2:
picks/cm
56 Fabric
3:
picks/cm
42 Fabric
4:
picks/cm
37
Variations of end and pick densities have an influence on the cross-section shapes of
yarns and their location inside the structure, which induce differences of homogeneity
of the 3D woven structure.
CONCLUSION
We have observed different real views at macroscopic scale of 3D warp interlock
fabrics thanks to thin slices of these impregnated fabrics. By using this technic,
evolution of cross-section shapes of yarns has been highlighted which mainly depends
on their position inside the 3D woven architecture. Based on the same weaving loom
to produce the same 3D warp interlock architecture, different end and pick densities
have been taken into account to compare the resulted final architecture coming from
these different fabrics. It has been revealed the influence of warp and weft yarns
densities on the final and real geometry of the 3D warp interlock fabric. Thanks to
these research results, more accurate geometrical model can be used into numerical
simulations which better fit the real geometry of 3D warp interlock fabrics
architecture.
Future works will be done on the influence of the weft insertion order onto the resulted
geometry of 3D warp interlock fabrics.
ACKNOWLEDGMENT
The authors would like to thank the ISL for funding this study during the final year
project of Caroline Chevalier (MS student). Special thanks to Nicolas Dumont,
Tomasz Kromoska and Frederick Veyet for their helps and advices during the design
and production of 3D warp interlock fabrics done on prototypes looms located in
Gemtex laboratory.
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Cristian I., Boussu F., and Nauman S. 2010. "Interesting parameters of 3D warp interlock fabrics
influencing the mechanical properties of the final composite structures," presented at 10th World
Textile Conference, Vilnius, Lithuania, June 21-23, 2010.
Boussu F. and Legrand X. 2008. “Interesting properties of 3D Warp interlock structures to
delamination and impact resistance”, in SEICO 08, SAMPE EUROPE International Conference
and Forum, Paris, France, March 31st. – April 2nd, 2008, pp. 297-302.
Islam A. 2015. 3D woven preforms for E-textiles and composites reinforcements. Advances in 3D
Textiles, X. Chen, Ed. Cambridge, UK: Woodhead Publishing, ch. 9, pp. 207-264.
Schmidt R., Bersuch L., Benson R., and Islam A. March 30, 2004. "Three dimensional weave
architecture," US patent 6 712 099 B2.
Schmidt R. and Kalser D. April 5, 2005. "Woven preform for structural joints," US Patent US 6 874
543 B2.
Boussu F., Dufour C., Veyet F., and Lefebvre M. 2015. Weaving processes for composites
manufacture, Advances in Composites Manufacturing and Processes - Part 1, P. Boisse, Ed.
Cambridge, UK: Woodhead Publishing, ch. 3, pp. 55 - 78.
Sheng S.Z. and Hoa S.V. 2003., "Modelling of 3D Angle Interlock Woven Fabric Composites",
Journal of Thermoplastic Composite Materials, 16 (1): 45-59.
Hu J. 2008. 3D fibrous assemblies, properties applications and modelling of three dimensional
textile structure, Woodhead publishing.
Vilfayeau J., Crepin D., Boussu F., Soulat D., and Boisse P. 2013. «Modélisation numérique du
procédé de tissage des renforts fibreux pour matériaux composites», presented at JNC 18, Nantes,
France, 12-14 juin 2013.
Vilfayeau J., Crepin D., Boussu F., Soulat D., and Boisse P. 2015. "Kinematic Modelling of the
Weaving Process applied to 2D fabric", Journal of Industrial Textiles, 45(3): 338–351.
Nauman S. March 2011. "Geometrical modelling and characterization of 3D warp interlock
composites and their on-line structural health monitoring using flexible textile sensors", Ph-D thesis
report, University of Lille 1, Lille.
Boussu F., Nauman S., and Cristian I. 2016. "Influence of process parameters on the final geometry
of 3D warp interlock fabric", presented at the 16th AUTEX World Textile Conference 2016,
Ljubljana, Slovenia, June 8–10, 2016.
Yurgartis S.W. and Jortner J. 1998. “Characterisation of yarn shape in woven fabric composites” in
Microstructural characterization of fibre-reinforced composites, Woodhead Publishing Limited.
Chevalier C. July 2012. "Étude de l'influence de paramètres intrinsèques à un tissu interlock sur ses
propriétés balistiques", Final year project report, ISL, Saint-Louis, France.
Boussu F., Cristian I., and Nauman S. 2015. "General definition of 3D warp interlock fabric
architecture", Composites Part B, 81: 171-188.