vtti center for injury biomechanicscomputational biomechanics (dr. costin untaroiu) rigid body...
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VTTI Center for Injury Biomechanics
Duma Gabler Hardy Kemper Rowson Untaroiu VandeVord
PARTNERS
Virginia-Maryland College of Veterinary Medicine
Institute for Critical Technology and Applied Science
Virginia Tech-Carilion Research Institute
Virginia Bioinformatics Institute
Virginia College of Osteopathic Medicine
Wake Forest University
BC I Biomechanics and Injury Prevention
• Mechanism (multiple scales):– Mechanical response,
– Injury response.
• Tolerance:– Injury metric/function to be evaluated (HIC, ADFS),
– Injury Assessment Reference Values (IARVs).
• Mitigation:– Tools for design/evaluation of environments and equipment,
• Physical and numerical models.
• Treatment:– Understanding mechanism can lead to improved diagnosis,
– Can provide foundation for new treatment regimes.
BC I
Application
Automobile Safety Military Sports Other
Head/Brain
Eye/face
Neck
Thorax
Upper limb
Pregnant
Pelvis
Lower limb
Body
Region
Blast
IED/Shrapnel
Head Mass
Restraints
Airbags
Work/time
Vehicle
Paratrooper
Treatment
Products
Stents
Treatment
Surgery
Violence
Pregnancy
Prosthetics
FMVSS 208
Airbag/Particle
Nij
Belt Loading
Airbag Loading
Restraints
Side Impact
Knee Bolster
Football
Softball
Football
Shoulder Pad
Brace Design
Eligibility
Football
Brace Design
CIB Research Areas
BC I CIB Activities
1. Empirical Biomechanics
Impact and injury response characterization
Transportation
Recreation
Military
Multiscale, multimodal, multirate investigation
Mechanism determination
Material property description
Tolerance quantification
Injury risk formulation
Surrogate implementation
Protective system evaluation
Mitigation strategy realization
2. Computational Biomechanics
(Dr. Costin Untaroiu)
Rigid body modeling
Finite element modeling
3. Test Subjects
Cadavers (PMHS)
Animals (rats, pigs)
Dummies (ATDs)
Human volunteers
BC I CIB Personnel and Funding
1. Personnel
Seven Principal Investigators
Four staff
Four post-doctoral fellows
Twenty-six graduate students
2. Funding
Historically maintain > $30m open
research
3. Historical Funding Sources
Department of Defense
National Highway Traffic Safety
Administration
Centers for Disease Control
NIH
NSF
NASA
OEM Automobile Manufacturers
Tier-One Suppliers
BC I Crash Sled and Impact Laboratory
• 1.4 MN
• 475,000 N-m
• 90 kph and 93 g (20 g/ms)
• 57 kph and 37 g
• 2500-kg payload
• High-frequency (500 Hz)
• 2-m driving stroke
SHARED
OFFICE
CONFERENCE
ROOM
PREPARATION
ROOM
HIGH SPEED
X-RAY
FREEZER
STORAGE
SERVO-SLEDEQUIPMENT
ROOM
MACHINE +
ELECTRONICS
SHOPOFFICES
CONTROL
CENTER
HIGH SPEED MTS
MACHINE
PNEUMATIC
IMPACTOR
C-ARM
FLUORO
GENERAL
STORAGE BATHROOM +
CHANGING AREA
OVERHEAD
DOOR
BC I High-Speed Biplane X-Ray
Accurate to within 0.1 mm in 0.05 cubic meter
A high-frequency
Dual-axis x-ray generator
80 kW: 150 kV or 1,000 mA
BC I Tissue Testing
Biaxial Tissue Testing
BC I Military Applications
APPROVED FOR PUBLIC RELEASE
BC I Accident Investigation, Simulation, Statistics
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 10 20 30 40 50 60 70
EDR Maximum Longitudinal Average Acceleration (G)
Pro
bab
ilit
y o
f S
eri
ou
s (
MA
IS 3
+)
Dri
ver
Inju
ry
10 ms
Criteria
50 ms
Criteria
BC I Finite Element Modeling
BC I Kelly Hall Building (Biomedical Laboratories)
Mini-sled
Vicon Motion Capture System-18 MX-T20 cameras (2 megapixel)
-Max Resolution = 1600 x 1280
-Max Sampling = 2000 fps
BC I VCOM II Building
VCOM
CLASSROOMS
CLASSIFIED
MILITARY AREA
CENTER FOR INJURY
BIOMECHANICS
BC I Computational Biomechanics (current/recent projects)
1. Development and validation of occupant/pedestrian human FE Models (e.g.
GHBMC, THUMS, etc,)
2. Testing and material identification of biological tissues (e.g. liver, spleen, ribs
etc.)
3. Statistical shape analysis of human organs
4. Development and validation of ATD FE models (e.g. THOR - automotive,
WIAMAN –military)
5. Adaptive restraint systems
BC I GHBMC occupant FE Model
• Geometry
– Reconstructed geometry of 50th male volunteer
– Additional data from literature for defining the cortical bone shells with thin thickness (e.g. in pelvis and epiphysis regions) and foot/hip ligaments
• Meshing
– Almost 625k elements and 322k nodes included in 285 distinct components (parts)
– More than 73% solid elements (93% hexa)
– All elements fulfill GHBMC mesh quality criteria (Jacobian solid/shell>0.3/0.4; Tet collapse>0.2, etc.)
– Model stable with 0.3/0.6 µs time steps (0.4/6% mass scaling)
• FE Model Validation
– 19 Component / sub-system validations
– 4 Robustness/Stability simulations
• Biomechanical Database
– Develop a biomechanical database which includes all validation data (loading curves, test setups etc.) corresponding to component validations
– Develop test data corridors
* This database obtained from published references /databases can be used in developments of further GHBMC FE models (e.g. 5th female)
Reference: Untaroiu et al. 2012- PLEX User ‘s Manual
GHBMC cortical thickness revised to match Anderson et al.,
2008
Foot model- 26 bones and 42 ligaments
Distribution of cortical shell thickness (calculated using a Matlab code based on bone surfaces)
GHBMC Pelvis and Lower Extremity Finite Element
Dr. Jaeho Shin
Neng Yue
BC I Development and validation of THOR-k FE Model
Jacob Putnam
( NASA,
former VT
MSc student)
Development of head neck
Frontal loadingVertical
loading
BC I ATD vs. Human under vertical loading
Photogrammetric
Imaging
* 18 Markers
* Localized to chair THOR THUMS
T=0 ms T=150 msT=75 ms
% Force Distributed Through Model
35%34%
8%
14%
7%10%
13%12%
6%
BC I Material modeling of abdominal organs
Dr. Yuan-Chiao Lu
(Uniformed Services
University of the
Health Sciences,
former VT PhD
student)
BC I GHBMC adult pedestrian FE Models
US (2012) 4,743 pedestrians killed & 76,000 pedestrians injured (NHTSA 2014)
BC I GHBMC adult pedestrian FE Models
Component validation Vehicle-to-pedestrian validation
Wansoo Pak (VT
PhD student)
student)
BC I GHBMC child pedestrian FE Models
Component validation Vehicle-to-pedestrian validation
0
1
2
3
0 5 10 15
Fo
rce
(kN
)
Displacement (mm)
Test data (6YO)
FE Data (Adult Mat. Prop.)
FE Data (Child Mat. Prop.)
Yunzhu Meng (VT
MSc student)
BC I Development and validation WIAMAN leg FE model
Wade Baker –
VT MSc
graduate
student
Wade Baker – VT
MSc student
WIAMAN better biofidelity than HIII !
Validation of WIAMAN FE Model
BC I Statistical Shape Analysis & Mesh Morphing
Keegan Yates – VT
PhD student
(Yates et al. 2016)
Original meshMorphed mesh
BC I Identifying TBI thresholds using animal and human FE models
Göttingen mini-pigs
BC I Identifying TBI thresholds using animal and human FE models
Animal
testing
Animal finite
element (FE)
model
Human FE
model
Simulate Injury
Develop specific
transfer function
PMHS testing
BC I Identifying TBI thresholds using animal and human FE models
Results – Horizontal Displacement (mm) Time (s) Histories
-0.4-0.2
00.20.4
0 0.02 0.04
-0.20
0.20.4
0 0.02 0.04
-0.20
0.20.4
0 0.02 0.04
-0.6-0.4-0.2
00.20.4
0 0.02 0.04
-0.20
0.20.40.6
0 0.02 0.04
(Yates et al. 2016)
BC I
• Simulations can be run
applying similar loadcases
to human models
– Allows investigation of
scaling methods
– Better scaling can be
developed
-50
50
150
250
350
0 2 4 6 8
Pre
ssu
re, k
Pa
Time, ms
With GHBMC Head
-50
50
150
250
350
0 2 4 6 8P
ress
ure
, kP
a
Time, ms
Pig Head w/o Scaling
Ommaya, A.K., et al., Scaling of experimental data on cerebral concussion in sub-human primates to
concussion threshold for man. 1967, DTIC Document.
Mao, H., et al., Development of a finite element human head model partially validated with thirty five
experimental cases. Journal of biomechanical engineering, 2013. 135(11): p. 111002.
Nahum, Alan M., and Randall W. Smith. An experimental model for closed head impact injury. No.
760825. SAE Technical Paper, 1976.
-50
50
150
250
350
0 2 4 6 8P
ress
ure
, kP
a
Time, ms
Pig Head w/ Scaling
Roughly
50% too
high
Identifying TBI thresholds using animal and human FE models
(Yates et al. 2016)
