|
Return
to September 2002 Newsletter
THOR
Advanced Crash Test Dummy
(50th Percentile Adult Male, Alpha
Version) |
|
NHTSA
Release to Public Domain
|
Figure 1. THOR Alpha Cutaway Model |
|
As a component of a long-term
research program dedicated to the reduction of automotive crash
trauma, the National Transportation Biomechanics Research Center
of the NHTSA Research and Development Office has directed the development
of an advanced crash test dummy, denoted as THOR. THOR has been
designed to assist both the development and the evaluation of advanced
vehicle occupant safety systems, and incorporates significantly
improved biofidelity and greatly expanded injury assessment capabilities
in all body regions. Though designed specifically for use in frontal
and oblique crash environments, the design offers multi-directional
capabilities in several of its components.
GESAC, Inc., of Boonsboro, MD, served as prime contractor to the
NHTSA for engineering development of this crash test device.
As an integral part of the THOR development program, the NHTSA has
actively involved the participation of worldwide automotive manufacturers,
research organizations, and government agencies in extensive test
and evaluation trials. Through the generosity and cooperative efforts
of expert individuals and institutions in North America, Japan,
Europe, and Australia, many useful refinements have been identified
and incorporated into the current THOR Alpha version (see Figure
1). |
|
| Functional Capabilities of THOR Alpha |
By virtue of its enhanced design and measurement
capabilities, THOR Alpha offers numerous functional benefits as compared
with previously existing crash test dummy technology:
- Assistance in optimization of "smart"
occupant restraint systems, including setting of air bag deployment
thresholds and design of integrated advanced belt/ bag restraint systems;
- Improved assessment of belt/ bag interactions;
- Improved head kinematics, as a result
of new neck and spine designs;
- Improved neck injury assessment, including
out-of-position injury assessment;
- More realistic spinal kinematics, as
a result of added spine flexibility;
- Facility for assessment of seated posture
effects upon restraint performance;
- Detection of air bag, belt, and wheel
rim interaction with the abdomen;
- Facility for injury assessment at the
hip joint;
- Detailed assessment of foot motions
and ankle/foot/tibia injury potential;
- Facility for localized facial injury
assessment
|
Figure 2. THOR Alpha Components
|
| To realize the above functional benefits,
THOR Alpha incorporates new design approaches in many component parts,
(Figure 2), as follows: |
- Load sensing face with regional
measurement capability (Figure 3);
|
- Multi-directional head/ neck
design with a) kinematic performance matched to human volunteer
frontal, lateral, and rear impact data, and b) distinct cervical
column and "muscular" load paths (Figure 4);
 |
- Human-like thoracic structure
with clavicle representation, multiple high-speed 3D deflection
instruments at four locations on the anterior ribcage, and optional
mid-sternum uni-directional displacement measurement (Figure
5);
|
Articulating spine with adjustable
vehicle-seated posture (Figure 6);
|
 |
- Improved shoulder design with
more human-like mobility (Figure 7);
|
 |
 |
- Restorable abdomen design featuring
an upper module with compression measurement and a lower module
with continuous bilateral 3D deflection measurements (Figure
8);
|
- Pelvis design with revised anthropometry
and flesh configuration, injury assessment capability at the
hips, and submarining detection features (Figure 9);
|
 |
- Compliant femur design to assist
in generation of more realistic femur loads (Figure 10);
|
 |
 |
- Lower extremity design (Thor-Lx)
with more human-like ankle/ foot motions, a representation of
the Achilles tendon load path, and substantially advanced injury
assessment capabilities (Figure 11);
|
|
|
A design intended for ease of
calibration, maintenance, and use.
|
|
| THOR Alpha Instrumentation |
THOR Alpha is capable of carrying a total
of 134 channels of data; see Figure 12 for details of instrument
locations. (Note: thorax mid-sternum x-displacement (optional),
knee shear displacement, knee angular displacement (optional), and Achilles
tendon tension (optional) instruments are not shown).
|
Figure 12. THOR Alpha Instrumentation
|
| THOR Alpha Instrumentation by Body Region |
| Head: |
9 Uniaxial Accelerometers
1 Biaxial Tilt Sensor |
| Face: |
Five Uniaxial Load Cells |
| Neck: |
Upper Neck Load Cell (6 channels)
Lower Neck Load Cell (6 channels)
Front Neck Cable Load Cell
Rear Neck Cable Load Cell
Head Rotation Potentiometer |
| Thorax: |
CRUX Deflection Units - 3 Dimensional
Displacement at each of Four Locations (UL, UR, LL, LR)- 4 CRUX
units @ 3 channels each;
Two Uni-directional Displacement String Potentiometers at Mid-Sternum
Location (optional);
1 Triaxial Accelerometer at the C.G. |
| Mid Sternum: |
1 Uniaxial Accelerometer |
| Upper Abdomen: |
Uni-directional Displacement String
Potentiometer
Uniaxial Accelerometer |
| Lower Abdomen: |
DGSP Deflection Units - 3 Dimensional
Displacement at L & R Locations (2 DGSP units @ 3 channels each) |
| Spine: |
1 Triaxial Accelerometer at T1 location
1 Triaxial Accelerometer at T12 location
T12 (5-axis) Load Cell
4 Biaxial Tilt Sensors |
| Pelvis: |
Acetabulum Load Cell (left and right,
3 channels each)
Iliac Crest Load Cells (1 each left and right)
1 Triaxial Accelerometer at Pelvis C.G. |
| Femur: |
Femur Load Cell (left and right, 6-axis
each) |
| Knee: |
Knee Shear Displacement, L&R
Knee Rotation (L&R, optional) |
| Lower Extremities: |
Upper Tibia Load Cell (L&R, 4
channels each)
Lower Tibia Load Cell (L&R, 5 channels each)
Tibia Acceleration (X, Y), each leg
Achilles Tendon Load Cell (each leg, optional)
Ankle Joint Rotation Potentiometers (X, Y, Z), each leg
Foot Acceleration (X, Y, Z), each leg |
|
Two multi-point 3D displacement measurement
systems are utilized in THOR Alpha. The CRUX precision solid link
design is utilized within the thorax at four locations (see Figure
13 for schematic right side installation), while the DGSP telescoping
joystick design is utilized within the lower abdomen (see Figure 14
for schematic right side installation). Multiple static tilt
sensors are also installed on THOR to assist laboratory personnel in precise
pre-test dummy positioning.
|
Figure 13. CRUX 3D Multi-Point Thorax Deflection Measurement
System
|
Figure 14. DGSP 3D Multi-Point Abdominal Measurement
System
|
| Scope of International THOR Test and Evaluation |
During the period of THOR development, an
extensive database of test results was acquired with the contributions
of numerous participating organizations and laboratories. Some 150 sled
test exposures at impact speeds ranging from 48 kmph to 64 kmph were conducted,
with peak decelerations ranging up to 30g. Frontal, oblique, and
rear tests were conducted in a variety of restraint systems: 3- point
belts, force-limiting belts, and belt + air bag combinations. Out of position
static air bag tests were also conducted to assess ATD durability and
response characteristics in this test environment.
In addition, fifteen full-scale vehicle crash tests were conducted, both
in U.S. NCAP and offset deformable barrier test conditions.
|
| Acknowledgement |
The process leading up to the development
and release of the THOR Alpha design has involved close cooperation and
consultation with many research organizations and automotive engineering
personnel worldwide. The NHTSA and THOR program principals extend their
sincere appreciation to the many individuals, research organizations,
and automotive manufacturers worldwide who have shared their advice and
expertise with the THOR project team:
Europe
- Renault, Volvo Car, SAAB, Autoliv Research AB,
Chalmers University
- EEVC/ADRIA: Transport Research Laboratory, TNO,
Polytechnic University of Madrid
North America
- NHTSA Vehicle Research and Test Center
- Transport Canada
- USCAR (GM, Ford, Daimler-Chrysler)
- Honda Research of America
- University of Virginia
- U.S. Federal Aviation Administration
- U.S. Department of Defense
Asia/ Pacific
- JAMA/ Japan Automobile Research Institute
- Australia (FORS)
- Autoliv Australia
|
| THOR Alpha Documentation Release |
As of December 14, 2001, NHTSA has released
version 1.1 of the THOR Advanced Crash Test Dummy (50th Percentile
Adult Male, Alpha Version) design to the public domain.
This version 1.1 release consists of the following downloadable components:
THOR Alpha DRAWING
PACKAGE, in AutoCAD 2000 format
Supporting Text Documents, as follows
(pdf format).
THOR Alpha USERS'
MANUAL
THOR Alpha CERTIFICATION
PROCEDURES DOCUMENT
THOR Alpha BIOMECHANICAL
REQUIREMENTS DOCUMENT
THOR Alpha THORTEST
PROGRAMS
THOR Alpha THORTEST
PROGRAMS-USERS' MANUAL
PLEASE NOTE: The
NHTSA has stipulated that all THOR Alpha components and
assemblies manufactured and delivered for use must conform
to the specifications and certification performance requirements
as defined within this release. Further, the NHTSA
has stipulated that all certification performance data
must accompany newly manufactured and delivered THOR Alpha
hardware.
Based upon the design concepts embodied
in this release, development of a 5th percentile female version
of THOR Alpha is now in progress. However, development of the
lower extremity portion of the small female THOR ATD has been completed,
for retrofit application at the distal femur interface of the small
female Hybrid III ATD. The NHTSA has released full documentation
for this component, called THOR-FLx/ HIIIr, to the public domain at:
http://www-nrd.nhtsa.dot.gov/departments/nrd-51/thor_flx/ThorFLxweb.html
In analogous fashion, the NHTSA has separately released detailed documentation
for THOR-Lx/ HIIIr, the lower extremity portion of the 50th
percentile male THOR Alpha for retrofit application to the Hybrid III
ATD, to the public domain at:
http://www-nrd.nhtsa.dot.gov/departments/nrd-51/thor_LX/Thorlxweb.html
For further information and a bibliography relevant to THOR
origins, engineering development, and refinement, see Foundations
and Elements of the NHTSA THOR Alpha ATD Design, presented
at the 17th International Technical Conference
on the Enhanced Safety of Vehicles, in Amsterdam, Holland.
For additional information with regard to the THOR Alpha
Advanced Crash Test Dummy, THOR-Lx/ Hybrid III Retrofit
Version, or the THOR-FLx Hybrid III Retrofit Version, please
contact Mr. Mark Haffner, Thor Program Manager, NHTSA National
Transportation Biomechanics Research Center, at (202) 366-4719
(phone) or by e-mail at mhaffner@nhtsa.dot.gov.
|
Return
to September 2002 Newsletter
|
