DEPARTMENT OF MATERIALS TEXTILES AND CHEMICAL ENGINEERING (MATCH) CENTRE FOR TEXTILE SCIENCE AND ENGINEERING (CTSE)
MECHANICAL MODELLING OF
REINFORCEMENT FABRICS USING A VIRTUAL FIBRE APPROACH WITH
HYBRID ELEMENTS
Lode DAELEMANS; B. Tomme; T.D. Dinh; B. Caglar; V. Michaud; J. Van Stappen; V. Cnudde; M. Boone and W. Van Paepegem
January 2021
In this presentation
Framework that allows the kinematic and mechanical modelling of reinforcement (woven) fabrics based on hybrid virtual fibres
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Virtual fibres Textile modelling Predictive simulations
Woven fabrics Through-thickness
compressive loading
The concept of virtual fibre modelling
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Fibrous nature of yarns Virtual fibres at yarn scale 3D modelling of textiles
Near-fibre scale precision Fibres realign under load
Differences to traditional FEM modeling
# virtual fibres determines accuracy;
Transversal material behaviour follows from the virtual fibers and is not explicitly defined;
Consider contact friction between virtual fibers.
Advantages of this near-microscale modelling approach
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Fibrous nature of yarns Virtual fibres at yarn scale 3D modelling of textiles
No need for a priori shape assumptions or µCT model extraction
Direct implementation of yarn parameters possible (twist, fibre type, …) Determination of input parameters for mesoscale modelling tools
Extreme deformation modes (discontinuous) possible, e.g. unravelling, splitting, …
State-of-the-art in virtual fibre modelling
Initially conceived around 2000 by Wang et al.
Several research groups currently using this method, for example
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SOME DIFFERENCES BETWEEN STUDIES Truss elements OR Beam elements
Kinematics OR Mechanics
Proprietary code OR Implemented in commercial FEA
Physics based input parameters OR Inversely determined input parameters
Our approach to virtual fibre modelling
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INPUT APPROACH APPLICATIONS
Datasheet values Fiber diameter;
Fiber linear density;
Fiber Young’s modulus;
Yarn tex;
Crimp;
Yarn count;
Weave schematic.
Experimental input
Non-elastic material properties;
Friction;
Bending stiffness.
High fidelity
50 – 100 virtual fibres per yarn;
Most-realistic approach.
Homogenised (simple)
Yarn properties without transversal behaviour;
Manufacturing
Virtual testing
Microstructural analysis
Cord twisting Tufting Weave compaction
Forming Coated fabrics Tensile, shear, flexure, …
Physics-based framework within commercial FEA software
Actual implementation
Each virtual fibre is a chain of truss-like elements
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Software
ABAQUS commercial FEA software Explicit solver
General contact algorithm
T3D2 truss elements, B31 beam elements
Hybrid truss-beam elements for bending stiffness
Assumptions
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Cross-sectional area virtual yarn equals that of real yarn.
1.
Mechanical properties of virtual fibre equal those real fibre, except for bending stiffness.
2.
Initial fabric microstructure is generated based on weave schematic and yarn crimp.
3.
𝐴
𝑣𝑦= 𝑛
𝑣𝑓𝜋
4 𝐷
𝑣𝑓2= 𝐴
𝑟𝑦= 𝑛
𝑟𝑓𝜋
4 𝐷
𝑟𝑓2→ 𝐷
𝑣𝑓1
𝑛
𝑣𝑓𝐸
𝑏𝑒𝑎𝑚𝐼
𝑣𝑓,𝑏𝑒𝑎𝑚= (𝐸𝐼 )
𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑1
In-plane virtual testing of a 3D woven fabric
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Tensile testing Shear testing
Finite element simulation of the woven geometry and mechanical behaviour of a 3D woven dry fabric under tensile and shear loading using the digital element method
L Daelemans, J Faes, S. Allaoui, G. Hivet, M. Dierick, L. Van Hoorebeke, W. Van Paepegem Composites Science and Technology (2016), 137, 177-187
Through-thickness compression
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From the experimental side
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2x2 twill weave Interglass E-glass fibres
390 g/m² Fabric
Through-thickness compression set-up
Compliance calibration procedure
In-situ µCT measurements
Uncertainty range
From the numerical side
13 Prof. Y. Wang
Kansas State University
Based on work of (Green et al. 2014)
Amount of virtual fibres per yarn
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Through-thickness compression simulation
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Dominating deformation mechanisms Fibre realignment
Fibre and yarn bending Transversal compaction
Very difficult loading to achieve predictive simulations
“Mesh convergence”
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61 virtual fibres per yarn Length-over-diameter ratio 1
L
D
Importance of virtual fibre bending stiffness
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Correct kinematics AND mechanics only with hybrid fibres
Experiment
Hybrid virtual fibres
Truss-only fibres
Truss-only fibres Truss-only fibres Hybrid virtual fibres
Hybrid virtual fibres
Which value of bending stiffness should we implement?
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Which value of bending stiffness should we implement?
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Measured bending stiffness (Peirce’s method) seems to give correct order of magnitude.
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Which value of friction
Simulated compressive response aligns well with the experimental measured one.
Typical glass-glass yarn friction values found in literature: 0.2 – 0.4
How to deal with decrease in surface area in virtual yarns?
Hysteresis
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Losses upon unloading are captured well by the simulations
Experiment Hysteresis losses
(J/m²) 6.72 ± 0.24 Simulation # virtual
fibers
𝑳/𝑫 𝑬𝑰 𝝁
61 1 𝐸𝐼𝑚𝑒𝑎𝑠 0.2 7.62
61 1 𝐸𝐼𝑚𝑒𝑎𝑠 0.35 8.04
61 1 𝐸𝐼𝑚𝑒𝑎𝑠 0.6 7.15
61 1 𝐸𝐼𝑚𝑒𝑎𝑠 0.8 7.06
61 1 2𝐸𝐼𝑚𝑒𝑎𝑠 0.35 7.92
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Conclusions
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Hybrid fibres offer a viable strategy for virtual fibre
modelling of the (out-of-plane) mechanical behaviour of textiles in commercial FEA packages
Accurate measurements of the platen-to-platen distance during compression
CONCLUSION
FUTURE WORK
Improved test method to determine yarn bending stiffness Friction law in function of the number of virtual fibres
Acknowledgments
Research Foundation – Flanders (FWO) FWO grant 12ZR520N
FCWO – UGent project G.0041.15N
Ghent University Special Research Fund BOF.EXP.2017.0007
Swiss Competence Center for Energy Research (SCCER) Mobility of the Swiss Innovation Agency (Innosuisse)
Swiss National Science Foundation SNF - 182669
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DEPARTMENT OF MATERIALS TEXTILES AND CHEMICAL ENGINEERING CENTRE FOR TEXTILE SCIENCE AND ENGINEERING
Lode DAELEMANS
Professor
CENTRE FOR TEXTILE SCIENCE AND ENGINEERING, DEPARTMENT OF MATERIALS, TEXTILES AND
CHEMICAL ENGINEERING (MATCH)
E LODE.DAELEMANS@UGENT.BE
T +32 9 264 57 51
WEBSITE HTTPS://WWW.TEXTILES.UGENT.BE
@UGENT_TEXTILES
@LDAELEMA
LODE DAELEMANS
