Premium Automotive Research and Development Programme
Crash Materials Technology
High Speed Testing, Characterisation and Modelling of
Materials and Joints
24th September 2007
Dr Paul Wood
Project Manager and Lead Engineer,
2nd floor IARC
University of Warwick
Coventry
CV4 7AL
07932 608084
http://www2.warwick.ac.uk/fac/sci/wmg/research/technology/autos/materials/
© 2007 IARC
Business Drivers
‰PARD – enhance capability of
UK suppliers to the automotive
industry
¾more effective use of
enabling technologies to;
¾reduce risk and cost in
product development
¾improve safety, innovative
car body designs, lighter
weight, lower unitary cost
¾increase competitiveness
© 2007 IARC
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Technology
‰Data input to crash simulation
software
¾material tensile data with strain rate
dependency
¾uncertainty and high cost in
generating material tensile data with
strain rate dependency
Same material tested at 10
labs around the world at a
relatively low strain rate
(10/s) as part of Round
Robin study c.2006
‰Leverage more value from
virtual crash testing
¾develop automotive industry
standard material data generation
and validation test procedures
Scope for PARD
© 2007 IARC
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Project Aim
‰Collaborative partnership with industry
‰Develop automotive test procedures (specimen designs, data
generation & validation techniques, recommendations, new
implementation ready material data cards)
‰Establish state-of-art high speed testing lab and expertise based
in West Midlands
‰Networking
‰Dissemination by publication
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Collaborative Partnership with Industry
Crash Technology Guild Members c2005
New partners c2007
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Data Generation and Processing
Raw Engineering Stress Strain Data
900
Design range of interest for crash structures is
0.001/s to 500/s (average ~ 60/s)
Stress [MPa]
Generate High Speed Tensile Data
<0.001/s
1.2/s closed loop (a)
1.2/s closed loop (b)
6.4/s closed loop (a)
6.4/s closed loop (b)
65/s open loop (a)
65/s open loop (b)
168/s open loop
0
0
5
10
15
20
25
30
Strain [%]
RAW TRUE DATA
1000
Transform to true plastic data
True Stress (Mpa)
Data Pre-Processing
0.001 /s
1.2 /s
1.2 /s
6.4 /s
6.4 /s
65 /s
65 /s
168 /s
420 /s
0
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
True Plastic Strain
DP600 strain rate flow curves with IARC fitted surface
Create a set or family of strain rate curves
True Stress (MPa)
Fit Material Model
0
0.00
Format Material Model
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
True Plastic Strain
For input to crash simulation design software
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0.20
Laboratory & Equipment
Stiff four column load frame
20 m/s tension & compression
5 MHz DAQ
Machine based sensors
Local instrumentation - strain
gauges on specimen
© 2007 IARC
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Specimen Design - Force Measurement
© 2007 IARC
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Specimen Design - Strain Measurement
© 2007 IARC
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Geometry affect on developed strain rate
Derived from strain gauge strain sensor on gauge length
© 2007 IARC
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Compare Optical Strain Measurement and Strain Gauge Results
Compare strain gauge strain
with ARAMIS strain for DP600
at test speed 15 m/s
2 cameras
= 3-D
1 camera
= 2-D
(no auto scale
feature)
Set camera
frame rate
Engineering strain converted to
true strain, filtered and
differentiated with time to
compare strain rate output from
strain gauge with Aramis
Strain gauge failure
© 2007 IARC
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Material Validation using High Speed Bend
© 2007 IARC
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Material Validation using Crush
ƒ Develop high and low speed
component tests and models
© 2007 IARC
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Broader Application of Testing Capability
© 2007 IARC
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Current Project Technical Objectives
‰
High speed joint failure
characterization for modelling
crash structures
‰
Improved productivity and
consistent quality of high speed
data generation
‰
Recommendations documentation of premium auto
test procedures
© 2007 IARC
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Vision - beyond current project
© 2007 IARC
Contact
Dr Paul Wood, Materials Project Manager,
2nd floor IARC,
University of Warwick,
Coventry.
CV4 7AL
07932 608084
© 2007 IARC
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