Transcript Collaborative Research:

ACMTRL
Collaborative Research:
Enhancing the Understanding of the Fundamental
Mechanisms of Thermostamping Woven Composites
to Develop a Comprehensive Design Tool
James Sherwood
Jennifer Gorczyca
University of Massachusetts Lowell
Collaborators:
Northwestern University
NSF/DOE/APC Workshop:
Future of Modeling in Composites Molding Processes
(Design & Optimization Session)
9-10 June 2004
Arlington, Virginia
NSF Grant Number:
DMI- 0331267
ACMTRL
Motivation
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Mass production of lightweight low-cost
woven-fabric reinforced composite parts
Desirable in automobiles for:
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High strength-to-weight ratio (compared to
metal counterparts)
Reduce weight  Increase fuel efficiency
Development of predictive design tool
ACMTRL
Motivation – Thermostamping
Punch
Binder Ring
Fabric
Die
ACMTRL
Motivation – Part Quality
[Wilks, 1999]
ACMTRL
Our Research:

Development of a friction model to capture the
behavior of balanced plain-weave composite
materials during thermoforming
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Incorporation of the friction model into the
commercial finite element code ABAQUS

Parametric study of the effect of processing
parameters on the reaction force on the punch

Use of the fabric friction model with a fabric
constitutive model in a commercial finite
element code such as ABAQUS to create a
predictive tool
ACMTRL
Our Research:
ACMTRL
Our Research:
H  Hersey
Number
h  use Power Law
viscosity model
U  fabric velocity
W  normal force
ACMTRL
State of the Art –
Testing Standards
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Study of metal/fabric interface relatively
new
ASTM standards exist to determine friction
coefficients of sheets
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Account for normal load and pull-out velocity
Do not account for sheet viscosity and fiber
orientation
Researchers have developed their own
test methods (many based on ASTM
Standard D 1894)
ACMTRL
State of the Art – Friction Testing
Table from: Gorczyca, Sherwood and Chen (2004). Modeling of Friction and Shear in
Thermostamping of Composites – Part I. Journal of Composite Materials. In Press.
ACMTRL
State of the Art – FEM
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Boisse et al. (1996, 2001a, 2001b)
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Constitutive model with FEM focuses on
formability
Based on Kawabata et al. (1973)
Xue et al. (2003) and Peng (2003)
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Focus on constitutive model and incorporation
into FEM
Use of shell elements and nonorthogonality
Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric
during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML
ACMTRL
State of the Art – FEM
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Cherouat and Billoët (2001)
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Sidhu et al. (2001)
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Truss elements – tows
Membrane elements – resin
Truss elements – tows
Shell elements – inter-tow
friction and fiber angle
jamming
Li et al. (2004) [@ UML]
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Truss elements – tows
Shell elements – increasing
tangent shear modulus
Fabric unit cell
Truss
Elements
Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric
during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML
Shell
Element
State of the Art – FEM
ACMTRL

1000
800
600
400
0
0.0
0.2
0.4
0.6
0.8
Time, s
0.5V, Fabric friction model
3000
2500
25000
1.02000
1500
0.5V, Coulomb friction model
Fabric friction
model, m=f(H)
1000
500
0
0.0
0.1
Coulomb friction
model, m=0.3
0.3
0.4
20000
15000
10000
0.5
Time, s
V, Fabric friction model
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0.2
Reaction Force on Punch, N
200
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Reaction force comparison
between fabric friction model
and Coulomb friction model
3500
Reaction Force on Punch, N
Reaction Force on Punch, N
1200
V, Coulomb friction model
5000
0
0.00
0.05
0.10
0.15
0.20
0.25
Time, s
2V, Fabric friction model
2V, Coulomb friction model
Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric
during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML
ACMTRL
Vision
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Ability to compare results from different testing methods
is important (i.e. shear frame and bias extension, and
friction)
Researchers must combine finite element modeling and
testing efforts to create a robust Design Tool for
thermoforming of woven-fabric composite materials
Analytical Design Tool will account for changing:
 Constitutive properties
 Temperature
 Friction properties
 Material types and weaves
ACMTRL
Vision
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Continue to collaborate with industry to:
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Ensure that the appropriate materials and
processing techniques are being investigated
Aid technology transfer from academia to
industry
ACMTRL
Perceived Gaps
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Researchers have determined modeling
techniques for specific materials, weave
types and cases
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These methods need to be extended to
include “generic” materials, weave types and
cases
ACMTRL
Perceived Gaps

Researchers have developed their own
testing methods (true for constitutive
property research and friction modeling)
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Work with ASTM for standardized test protocols
Analytical methods for comparing test data using
different test procedures must be proposed,
publicized and peer-reviewed
ACMTRL
Research Thrusts
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Collaborative research among modeling
laboratories:
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Comparison and interpretation of differences
in results among different modeling
techniques
Joining of different fabric models, such as
friction and constitutive, in model of forming
processes and interpretation and publication
of results
Use these methods to lead to models for
“generic” materials, weaves and cases
ACMTRL
Research Thrusts

Collaborative research among testing
laboratories:


Comparison and interpretation of differences
in results using different test procedures
Use these comparisons to work towards
standardization of tests and to determine
strengths and weaknesses of the different
tests that are available
ACMTRL
Collaborative Research:
Enhancing the Understanding of the Fundamental
Mechanisms of Thermostamping Woven Composites
to Develop a Comprehensive Design Tool
James Sherwood
Jennifer Gorczyca
University of Massachusetts Lowell
Collaborators:
Northwestern University
NSF/DOE/APC Workshop:
Future of Modeling in Composites Molding Processes
(Design & Optimization Session)
9-10 June 2004
Arlington, Virginia
NSF Grant Number:
DMI- 0331267