Materials Characterisation and Simulation
Physical Inputs to Finite Element Crash Design Tools
Design Requirements
Technical Service
Strain Rate Data Generation, Modelling
and Formatting
•
Controlled strain rate data generation over
seven decades of strain rate up to 1000/s,
conforming to Ford Premium Automotive
Group test procedures, VDEh and IISI
recommendations
•
Implementation ready material models for
use in commercial finite element tools, and
customised to end user application
•
•
Material model validation
•
Unique lab facilities, measurement system
and capability to test a wide range of
materials, jointed coupons and components
•
Fast delivery
600
400
200
0
0
5
10
15
True Stress (Mpa)
Engineering stress (MPa)
800
20
25
DP600 strain rate flow curves with IARC fitted surface
30
0
0
0.05
0.1
True Plastic Strain
True Stress (MPa)
Engineering Strain (%)
0.15
0.2
Development of customer specific test
procedures, instrumentation and specimen
designs for high rate data generation
0
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
True Plastic Strain
Material Model Validation
Joint testing
specimen
Material testing
specimen
Measured Force (kN)
14
Application Area of Technology
•
Improved confidence and efficiency in
application of virtual testing technology
to product development
•
Improved crashworthiness: compliance
to world wide crash regulation, NCAP,
insurance and pedestrian safety
requirements
•
Reduce time, cost and risk to introduce
new materials to develop new car body
designs
•
•
Reduce mass of car body structure
5000 mm/s
2000 mm/s
800 mm/s
100 mm/s
10 mm/s
12
10
8
6
4
2
0
0
10
20
30
40
Actuator Displacement (mm)
End Application of Material Model
Eco-friendly technology
Copyright 2007
50
Materials Characterisation and Simulation
Physical Inputs to Finite Element Crash Design Tools
High Speed Test Laboratory, Equipment and
Capability
•
Precision servo-hydraulic machine with closed and
open loop control features
•
•
Actuator velocity from 1 mm/s up to 20 m/s
•
Fast jaw Technology - acceleration of complete
moving grip before testing starts
•
Stiff 4 column load frame for controlled testing of
components and joined assemblies
•
Velocity profile correction under open loop control for
high speed testing
•
High accuracy data acquisition with logging
frequency of 5 MHz and 12 bit resolution
•
Custom built high frequency force transducers for
high accuracy stress measurements
•
Local instrumentation fully integrated within signal
conditioning unit e.g. custom built transducers and
special strain gauges exposed to high speed and
large strain
•
Modelling experiment - specimen geometry, system
of measurement and test boundary conditions
Controlled tensile and compression testing up to 100
kN static load (160 kN dynamic load)
Medium strain rate specimen design
20.00
100
18.00
90
16.00
80
14.00
70
12.00
60
10.00
50
8.00
40
6.00
30
4.00
Strain Rate [1/s]
Strain [%]
Grip speed of 5 m/s: Gauge length 60 mm
20
2.00
0.00
0.037
- strain sensor strain
- strain sensor strain rate
0.0375
0.038
0.039DP600
0.0395
0.04
0.0405
Load-Filtered
Actuator0.0385
Position, Steel
(2mm), Dynamic
(5 m/s)
10
0
0.041
Time [s]
18
20.00
800
16
18.00
14
700
12
14.00
600
12.00
10
500
10.00
8
400
8.00
6
6.00
Machine Mounted Force Sensor Output
4
Mounted Forceforce
Sensor Output
- machineSpecimen
dynamic
sensor
- specimen transducer
4.00
2
2.00
300
200
0.00
100
0
0.02225 0.0223 0.02235 0.0224 0.02245 0.0225 0.02255 0.0226 0.02265 0.0227
0
Dr. Paul Wood
Mobile: +44 (0)7932 608084
Email: P.K.C.Wood@warwick.ac.uk
LVDT Actuator
Position [mm]
Time [s]
Dr. Claus Schley Dipl.-Ing., PhD
Mobile: +44 (0)7932 729053
Email: Claus.Schley@warwick.ac.uk
IARC Copyright 2008
Strain Rate [1/s]
Strain [%]
Load [kN]
16.00