Physics-based Computational Modeling of Knitted Textiles
Daniel Christe1,2, Chengyang Mo1, Dani Liu1, Krzysztof Mazur1, Aditi Ramadurgakar1,2, Shane Esola1, and Antonios
1*
Kontsos
1Department
of Mechanical Engineering & Mechanics
2Department of Materials Science & Engineering
*Corresponding Author e: akontsos@coe.drexel.edu | t:215-895-2297
Multiscale Modeling Approach
Introduction
• Garment devices are hierarchically structured material
systems
exhibiting complex (micro) structure-property-behavior relations
driven by yarn-level interactions. Accurately capturing this behavior in
simulation is key for advancing predictive design of functional garments.
• The Shima Seiki Haute Technology Lab at Drexel University’s ExCITe
Center brings the capability to rapidly manufacture knitted garments
from diverse materials, including steel, Kevlar and spider silk. However,
a fundamental knowledge gap remains in the ability to predict the
performance of a given design, due to complex textile mechanics.
• Compared to processing routes for other materials such as metal alloys,
knitting allows the designer much greater control over the material
structure, advancing the concept of “knits-by-design” and fitting the
broader “materials-by-design” framework [1,2].
Objectives
Theoretical & Applied Mechanics Group
Applications
Knit Pattern
1 Loop
Figure 1: Generation of knit geometries in an open source textile generator (TexGen), from single knit loop to knit pattern level. Such
structures are directly exportable to finite element environments (e.g. Abaqus) for computational mechanics simulations, with data
obtained from physical/mechanical evaluation of actual structures.
(a)
(c)
(b)
• To characterize mechanical behavior of knitted textiles using a suite of
quantitative Non-Destructive Evaluation methods in parallel with
multiscale mechanical testing.
• To develop robust data-driven simulation tools to study mechanical &
multi-physics behavior of smart textiles.
(N)
Drexel University, Department of Electrical and
Computer Engineering
Design & Manufacturing
(b)
[5]
(M)
Figure 6: Textiles are tailorable, shape-conformal platforms for devices,
with envisioned for energy storage, actuation, and sensing applications.
SDS-One Apex Design System
(a)
[4]
Figure 2: (a) Meshed geometrical model with boundary conditions shown, based on ASTM D4964 pertaining to constant rate-ofextension testing of fabrics (b) Von Mises stresses for a RVE(Representative Volume Element) (c) Force-displacement results for
different friction coefficients under uniaxial tension for 2 RVEs in static FEA.
Concluding Remarks
Characterization
Mechanical Testing + Quantitative Non-Destructive Evaluation (QNDE)
[3]
Scanning Electron Microscopy (SEM)
Desktop Mechanical Tester
(a)
(b)
(a) 2D encoding of the knitting pattern as (b) Preview of the resulting fabric
specified by the designer
in Knit Paint design software
•
(c)
Digital Image Correlation (DIC)
Figure 3: SEM Images of (a) Garter stitch (b) Jersey stitch (c) Rib stitch
(c) Shima Seiki SSG122SV knitting machine at the ExCITe Center
As stated, a major objective of this work is to provide quantitative
feedback to design and manufacturing operations. This will be
accomplished through a framework coupling design and simulation
with testing and evaluation of actual knitted materials at multiple
length scales. This work serves as a basis for the development of
predictive “process-aware” design tools, reducing reliance on costly
“Edisonian” trial-and-error approaches.
• Smart textiles are an excellent example of a hierarchically structured
material system. The integrated framework of experiments coupled
with physics-based modeling presented herein can potentially serve as
a more general template for component-level design of hierarchical
material systems, accelerating the traditionally slow materials
development cycle.
References
[1] Pollock, T., et al. (2008). Integrated Computational Materials Engineering: A Transformational
Discipline for Improved Competitiveness and National Security, National Academy of Engineering.
[2] Kalidindi, S. R. (2015). "Data science and cyberinfrastructure: critical enablers for accelerated
development of hierarchical materials." International Materials Reviews 60(3): 150-168
[3] Photo of an SDS-One Apex workstation. Retrieved from TEXDATA International
www.texdata.com/news/2/7267.SHIMA-SEIKI-to-exhibit-at-Premi%C3%A8re-Vision-Paris.htm
[4] K. Jost, D. Stenger, C. R. Perez, J. K. McDonough, K. Lian, Y. Gogotsi, et al., "Knitted and screen
printed carbon-fiber supercapacitors for applications in wearable electronics," Energy &
Environmental Science, vol. 6, p. 2698, 2013.
[5] (2015) Lockheed Martin Human Universal Load Carrier. Available
http://www.lockheedmartin.com/us/products/hulc.html
(d) Mechanical testing specimens, knitted with a high-contrast
speckle pattern for full-field strain mapping via digital image correlation.
(a) Sample
(b) U2
(c) ε22
Figure 4: (a) Clamped sample, (b) full-field displacements, and (c)
strains computed through DIC
Figure 5: Loading profile for three simple knits
Acknowledgments
This work is a collaborative effort with Assistant Professor Geneviève Dion and Chelsea Knittel from the College of
Media Arts & Design, and Associate Professor David E. Breen from the College of Computing & Informatics of Drexel
University.