JEC COMPOSITES MAGAZINE - Issue #121 - May 2018 - 69

3D textile-reinforced composites: from manufacturing to structural design

Fig. 7: Overview of multi-scale modelling: (a) simulated warp-directional stressstrain curves along the experimental upper and lower bounds (left y-axis); evolution
history of di in the matrix/collective warp/weft component (right y-axis); (b) statistical distribution of the damage value when the peak stress value is reached with
yarn breakage in the warp yarns (d1) (loading along the warp direction) [1]
Fig. 6: The computed local fibre orientations are distributed along the binder path,
taking the real model as an example [1]

dure suggested in [3], the 3D image domain was partitioned into
a number of voxels by imposing two user-assigned parameters:
voxel size and integration window size (all the units of size are in
pixels). The derivate variables attached to each voxel were determined at the end of the discretization stage:
the AGV was estimated over the whole voxel domain; the degree
of anisotropy was calculated via an eigenvalue analysis on the
structure tensor.
Multi-scale material modelling
Two-scale numerical homogenization schemes are one of the
effective methodologies that can be used to integrate material
properties variations after manufacturing.
At this step, the experimental observations and mathematical
modelling are related.
The data obtained from CT scans or SEM images is transformed into a finite element model with a developed non-linear material behaviour.
This work was conducted in collaboration with a team from
the Department of Materials Engineering (MTM) of KU
Leuven.
Some key results are briefly presented in Figure 7.
Figure 7a shows the knock-down effect due to partial fibre
bundle breakage on the predicted strength value.
Two models were compared:
the first one did not take into account the local defects of the
textile (shown in green) and the second one had a modified
geometry with partially broken bundles (shown in red).
A qualitative and statistical analysis is also shown in
Figure 7b.
The left-skewed distribution of damage values shows a small
overall damage intensity.
For the model that takes into account broken fibre bundles,
the already-formed damage slightly propagates along the yarn
width, while new damage appears wherever the non-smooth
surfaces are reconstructed.
This model tends to show a lower damage ratio but a higher
degree of damage.

Conclusion
The works described in this paper just lift the veil over the
wide range of problems associated with composite materials
modelling in general, and 3D textile composites in particular.
It also shows the great interest of having a complete numerical
methodology that takes into account a variety of experimental
observations at different manufacturing steps in order to complete the design of future structural components with key and
decisive material data.

More information:
Web Carnot-MINES: www.carnot-mines.eu
Web IMT Lille Douai: www.imt-lille-douai.fr
dmytro.vasiukov@imt-lille-douai.fr

Acknowledgements
Dr. Yang Liu wishes to acknowledge the financial support of the
China Scholarship Council for funding his PhD grant. The authors
also gratefully acknowledge Stepan V. Lomov, Professor at the
Department of Materials Engineering (MTM) of KU Leuven and
Toray professor (Toray Chair for Composite Materials in KU Leuven),
Stephane PANIER (former Professor at IMT Lille Douai, currently
Professor at IUT GMP Amiens), and the Carnot MINES Institute.

References
[1] Liu Y, Straumit I, Vasiukov D, Lomov SV, Panier S. Prediction of linear and nonlinear behavior of 3D woven composite
using mesoscopic voxel models reconstructed from X-ray
micro-tomography. Compos Struct 2017; 179:568-579.
[2] Labanieh AR, Liu Y, Vasiukov D, Soulat D, Panier S.
Influence of off-axis in-plane yarns on the mechanical
properties of 3D composites. Compos Part A Appl Sci Manuf
2017; 98:45-57.
[3] Straumit I, Lomov SV, Wevers M. Quantification of the
internal structure and automatic generation of voxel models
of textile composites from X-ray computed tomography data.
Compos Part A Appl Sci Manuf 2014; 69:150-158.

N°121 May - June 2018

/ jec composites magazine

http://www.carnot-mines.eu http://www.imt-lille-douai.fr

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #121 - May 2018