Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD Abdomen/Pelvis ...

113 Pages·2014·7.21 MB·English

DOT HS 812 088 January 2015
Comparative Evaluation of
6-Year-Old Hybrid III and
DAPRR Prototype ATD
Abdomen/Pelvis Components
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Suggested APA Format Citation:
Hagedorn, A., & Stammen, J. (2015, January). Comparative evaluation of
6-year-old Hybrid III and DAPRR prototype ATD abdomen/pelvis components.
(Report No. DOT HS 812 088). Washington, DC: National Highway Traffic
Safety Administration.
TECHNICAL REPORT DOCUMENTATION PAGE

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.
DOT HS 812 088

4. Title and Subtitle January 2015

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype
ATD Abdomen/Pelvis Components 6. Performing Organization Code
NHTSA/NVS-311

7. Author(s) 8. Performing Organization Report No.
Alena Hagedorn, Transportation Research Center Inc.; Jason
Stammen, Ph.D. of NHTSA’s Vehicle Research & Test Center

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)
National Highway Traffic Safety Administration
Vehicle Research and Test Center 11. Contract or Grant No.
10820 SR 347; P.O. Box B37
East Liberty, OH 43319-0337

12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered
National Highway Traffic Safety Administration Final Report
1200 New Jersey Avenue SE.
14. Sponsoring Agency Code
Washington, DC 20590 NHTSA/NVS-311

15. Supplementary Notes

16. Abstract

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known
as DAPRR) has been developed for the Hybrid III 6-year-old child ATD. The pelvis and abdomen are
intended to better identify lap belt intrusion into the occupant’s abdomen in restraint evaluation tests. More
biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when
using the 6-year-old ATD. Both component level and dynamic sled tests were conducted on a Hybrid III 6-
year-old with either the standard abdomen – pelvis structure (HYIII 6YO) or the prototype package with gel-
filled abdomen and revised pelvis (DAPRR). Abdomen impact tests conducted with both dummies were
repeatable and revealed that the DAPRR abdomen showed more penetration as test rate increased from 1.5 to
2.5 m/s. In addition, the DAPRR abdomen stiffness was independent of test rate. In belt pull tests, the
DAPRR was more consistent with the biofidelity corridor than the HYIII 6YO. Sled tests indicated that the
DAPRR was more sensitive to different types of restraint conditions than the HYIII 6YO, and that current
FMVSS No. 213 injury assessment reference values (IARVs) were not significantly altered by DAPRR
design changes from the standard Hybrid III. An alternative method for calculating abdomen penetration in
the 6YO was developed, and the results were encouraging based on similarity in anterior superior iliac spine
(ASIS) force versus abdomen penetration responses between belt pull component tests and sled testing.
Overall, for all test modes, the DAPRR tended to display more abdomen penetration at lower force levels
than the stiffer HYIII 6YO. In summary, the DAPRR prototype package appears to improve the sensitivity
of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury.

17. Key Words 18. Distribution Statement
Abdomen, ATD, Hybrid III, DAPRR, 6-year-old Document is available to the public from
the National Technical Information Service
www.ntis.gov
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price
Unclassified Unclassified 113
Form DOT F 1700.7 (8-72)
Reproduction of completed page authorized
i
EXECUTIVE SUMMARY

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen
(together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD. The
pelvis and abdomen are intended to better identify lap belt intrusion into the occupant’s abdomen
in child restraint tests. More biofidelic abdomen and pelvis components could therefore improve
the prediction of abdomen injury when using the 6-year-old ATD.

Component level (pendulum impact and belt pull) and dynamic (sled) tests were conducted on a
Hybrid III 6-year-old with either the standard abdomen – pelvis structure (HYIII 6YO) or the
prototype package with gel-filled abdomen and revised pelvis (DAPRR). Overall, for all test
modes, the DAPRR allowed for more abdomen penetration at lower force levels. The HYIII
6YO was stiffer, allowing much less penetration and higher intrusion force.

Pendulum impact tests conducted with both dummies were repeatable. However, the impact bar
tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen
compression. The DAPRR showed increasing penetration with increasing test rate; stiffness was
independent of test rate despite the presence of viscous material within the abdomen structure.

In the belt pull tests, abdomen force penetration curves were compared to a pediatric biofidelity
target. The HYIII 6YO was stiffer than the DAPRR and showed much less penetration. In
addition, the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO. Results
from the high and low belt placement tests on the DAPRR indicate that the high placement
yielded slightly higher force levels but similar maximum penetration.

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the
HYIII 6YO. Evidence of this was found in increased abdomen penetration and pelvis rotation as
the test configuration increased in severity. An alternative method for calculating abdomen
penetration in the 6YO was developed and appears to have potential based on similarity in ASIS
force versus abdomen penetration responses between belt pull component tests and sled testing.
In a few tests, the DAPRR abdomen moved out of position from the pelvic cavity. A method for
better stability of the abdomen within the pelvis is necessary. While some differences were
observed between the FMVSS No. 213 injury assessment reference values (IARVs) measured by
the two dummies, these particular measurements did not appear to be significantly altered by
DAPRR design changes.

In summary, the DAPRR package appears to improve the sensitivity of the Hybrid III 6-year-old
ATD to kinematic conditions associated with abdominal injury. The abdomen and pelvis are
more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD
design. Ongoing work includes refinement of the abdomen penetration measurement technique
and better stabilization of the abdomen within the pelvis. If an instrumented version of the gel
abdomen becomes available in the future, repeat tests will be done to compare with the results
from this report.

ii
Table of Contents

1.   Background............................................................................................................................. 1

2.   Methods................................................................................................................................... 3

2.1.   Pendulum Impacts to Abdomen ....................................................................................... 3

2.1.1.   Methodology............................................................................................................. 4

2.1.1.1.   Calculating Abdomen Penetration ..................................................................... 7

2.1.2.   Results and Discussion ............................................................................................. 8 

2.2.   Seat Belt Pull Tests ........................................................................................................ 14

2.2.1.   Methodology........................................................................................................... 15

2.2.2.   Calculating Belt Load Force, Abdomen Penetration, and Velocity ........................ 19 

2.2.2.1.   Calculating Belt Loading Force....................................................................... 20

2.2.2.2.   Calculating Abdomen Penetration ................................................................... 20

2.2.2.3.   Calculating Abdomen Penetration Velocity .................................................... 20

2.2.3.   Results and Discussion ........................................................................................... 20 

2.3.   Sled Tests ....................................................................................................................... 22

2.3.1.   Methodology........................................................................................................... 28

2.3.2.   Abdomen Penetration.............................................................................................. 31 

2.3.3.   Results and Discussion ........................................................................................... 33 

2.3.3.1.   40 km/h Sled Tests (1-4) ................................................................................. 33

2.3.3.2.   FMVSS 213 (48 km/h) Tests (5-12) ................................................................ 39 

3.   Conclusions........................................................................................................................... 52

iii
APPENDIX A: Test 1 Plots (40 km/h, 5-point Harness).............................................................. 54

APPENDIX B: Test 2 Plots (40 km/h, Backless Booster) ............................................................ 58 

APPENDIX C: Test 3 Plots (40 km/h, Highback Booster) .......................................................... 62 

APPENDIX D: Test 4 Plots (40 km/h, No CRS).......................................................................... 66 

APPENDIX E: Test 5 Plots (48 km/h, 5-point Harness) .............................................................. 70

APPENDIX F: Test 6 Plots (48 km/h, Backless Booster) ............................................................ 74 

APPENDIX G: Test 7 Plots (48 km/h, Highback Booster) .......................................................... 78 

APPENDIX H: Test 8 Plots (48 km/h, Backless Booster) ........................................................... 82 

APPENDIX I: Test 9 Plots (48 km/h, Highback Booster)............................................................ 86 

APPENDIX J: Test 10 Plots (48 km/h, No CRS) ......................................................................... 90 

APPENDIX K: Test 11 Plots (48 km/h, No CRS, 7° Bench Angle) ............................................ 94 

APPENDIX L: Test 12 Plots (48 km/h, No CRS, Lap Belt, 7° Bench Angle) ............................ 98 

APPENDIX M: Abdomen Penetration Analysis ........................................................................ 102 

APPENDIX N: Neck Loads and Chest Compression................................................................. 103 

iv
List of Tables

Table 1. Test Modes for the HYIII 6YO and DAPRR Dummies ................................................... 3 

Table 2. Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO ............. 3

Table 3. 6YO Pendulum Test Instrumentation ............................................................................... 4 

Table 4. Summary of Abdomen Penetration From Pendulum Tests .............................................. 8

Table 5. Results of HYIII 6YO and DAPRR Abdomen Impacts ................................................... 9

Table 6. Seat Belt Pull Test Matrix ............................................................................................... 15

Table 7. 6YO Seat Belt Pull Test Instrumentation ....................................................................... 18

Table 8. Polarities for Seat Belt Testing and Calculations ........................................................... 19

Table 9. Seat Belt Pull Test Results .............................................................................................. 22 

Table 10. HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix ......................................... 23 

Table 11. 6YO Sled Test Instrumentation .................................................................................... 29 

Table 12. 6YO Sled Tests 40 km/h Current 213 IARVs .............................................................. 34

Table 13. 6YO Sled Tests 40 km/h Abdomen and Lumbar Measurements ................................. 35 

Table 14. 6YO Sled Tests 48 km/h (FMVSS 213) Pulse Current 213 IARVs ............................. 40 

Table 15. 6YO Sled Tests 48 km/h (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 ....................................................................................................................... 42

Table 16. 6YO Sled Tests 48 km/h (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 ..................................................................................................................... 43

v
List of Figures

Figure 1. Features of DAPRR abdomen and pelvis components .................................................... 2 

Figure 2. DAPRR gel abdomen with Ethafoam inserted behind abdomen .................................... 4 

Figure 3. Alignment of the probe bar just above pelvis in the DAPRR ......................................... 5 

Figure 4. Setup for pendulum impacts to the DAPRR abdomen; (top) probe alignment and

(bottom) test setup .......................................................................................................... 5 

Figure 5. Probe alignment in HYIII 6YO impacts .......................................................................... 6 

Figure 6. Setup for abdomen pendulum tests with the HYIII 6YO ................................................ 6 

Figure 7. Pendulum force versus abdomen penetration in DAPRR pendulum impacts ............... 10 

Figure 8. Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts .......... 11 

Figure 9. DAPRR and HYIII 6YO average force-penetration 1.5m/s .......................................... 12 

Figure 10. DAPRR and HYIII 6YO average force-penetration 2.0m/s ........................................ 12 

Figure 11. DAPRR and HYIII 6YO average force-penetration 2.5m/s ........................................ 13 

Figure 12. High belt position for DAPRR belt pull tests.............................................................. 14 

Figure 13. Low belt position for DAPRR belt pull tests............................................................... 14 

Figure 14. Belt position for HYIII 6YO belt pull tests ................................................................. 15 

Figure 15. DAPRR 6YO in seat belt pull device .......................................................................... 16 

Figure 16. HYIII 6YO in seat belt pull device .............................................................................. 16

Figure 17. Setup for belt pull tests showing instrumentation ....................................................... 17 

Figure 18. Stringpot configuration for pelvis displacement measurement ................................... 17 

Figure 19. Belt and pelvis stringpot configurations ...................................................................... 19 

Figure 20. Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) – all tests 95 psi ................................... 21 

Figure 21. Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation.................................................................................................................... 23 

Figure 22. Sled Test 1 five-point harness ..................................................................................... 24 

Figure 23. Sled Test 2 backless CRS ............................................................................................ 24 

Figure 24. Sled Test 3 high back CRS .......................................................................................... 24 

Figure 25. Sled Test 4 three-point belt only ................................................................................. 25 

Figure 26. Sled Test 5 five-point harness ..................................................................................... 25 

Figure 27. Sled Test 6 backless CRS ............................................................................................ 25 

Figure 28. Sled Test 7 high back CRS .......................................................................................... 26 

Figure 29. Sled Test 8 backless CRS ............................................................................................ 26 

Figure 30. Sled Test 9 high back CRS .......................................................................................... 26 

Figure 31. Sled Test 10 three-point belt only ............................................................................... 27 

Figure 32. Sled Test 11 three-point belt only with 7° seat pan angle ........................................... 27 

Figure 33. Sled Test 12 lap belt only with 7° seat pan angle ........................................................ 28

Figure 34. Examples of seat belt accelerometers and ARS .......................................................... 30 

Figure 35. Pelvis motion block installed in the DAPRR dummy ................................................. 31

Figure 36. Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement ............................................................................................................... 33 

Figure 37. Abdomen penetration comparison for 40 km/h tests ................................................... 34 

Figure 38. Total ASIS force comparison for 40 km/h tests .......................................................... 36 

Figure 39. Total ASIS force versus X abdomen penetration for 5-point harness Test 1 .............. 37

vi
Figure 40. Total ASIS force versus X abdomen penetration for backless CRS Test 2 ................ 37 

Figure 41. Total ASIS force versus X abdomen penetration for high back CRS Test 3 .............. 38

Figure 42. Total ASIS force versus X abdomen penetration for 3-point belt Test 4 .................... 38

Figure 43. Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR ....................................................................................................................... 41

Figure 44. Abdomen penetration comparison for 48 km/h tests ................................................... 44 

Figure 45. Total ASIS force versus X abdomen penetration for 5-point harness Test 5 .............. 45

Figure 46. Total ASIS force versus X abdomen penetration for 3-point belt Test 6 .................... 45

Figure 47. Total ASIS force versus X abdomen penetration for high back CRS Test 7 .............. 46

Figure 48. Total ASIS force versus X abdomen penetration for backless CRS Test 8 ................ 46 

Figure 49. Total ASIS force versus X abdomen penetration for high back CRS Test 9 .............. 47

Figure 50. Total ASIS force versus X abdomen penetration for 3-point belt (16°) Test 10 ......... 47

Figure 51. Total ASIS force versus X abdomen penetration for 3-point belt (7°) Test 11 ........... 48

Figure 52. Total ASIS force versus X abdomen penetration for lap belt (7°) Test 12 ................. 48 

Figure 53. Top of abdomen “rolling out” of pelvis ...................................................................... 49 

Figure 54. Using tape to hold abdomen in place to minimize “rolling out” ................................. 49 

Figure 55. Pelvis rotation (about pelvic Y axis) comparison chart ............................................... 50

Figure 56. Total ASIS load comparison for 48 km/h tests ........................................................... 51

Figure 57. Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests............................................................................................................... 51

vii
1. Background

The abdomen is the second most commonly injured body region after the head/face in young
children using vehicle seat belts and can be associated with significant health care costs.1 In a
case series of 98 children with “seat belt syndrome” injuries, the mean age was 7.3 ± 2.5 years
and 72 percent were from 5 to 9 years old.2 An analysis of over 200,000 children in crashes
identified age as a primary factor for elevated abdominal injury risk.3 Children 4 yo 8 years old
were at the highest risk of abdominal injury; they were 24.5 times and 2.6 times more likely to
sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years
old, respectively. The developmental and geometric characteristics of the 4- to 8-year-old child
pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these
injuries. Thus, this age group is targeted as the primary age range to benefit from belt-
positioning booster seat use.

In addition to injury trends, differences have been identified between human and child ATD
pelvis geometries. It has been observed that the anterior superior iliac spine (ASIS) landmark on
the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD), hereafter referred to
as the HYIII 6YO, is higher relative to the thigh-abdomen junction, than on similar sized
children.4 5 Given the importance of lap belt placement with respect to the pelvis, it is important
that the ATD pelvis has a biofidelic anthropometry.

Currently, there is no current pediatric ATD that can accurately track the abdominal response to
belt loading and thus the risk of injury. The injury trends and pelvis geometry discrepancies
noted above both point to the HYIII 6YO as the prime candidate for an improved
abdomen/pelvis design.

In the early 2000s, a collaborative research effort was undertaken with the goal of developing a
new ATD abdomen and pelvis design.1 This effort included an epidemiological analysis of
abdomen injuries to identify risk factors,3 an anthropometry study to provide geometric
specifications for a modified pelvis,6 an experimental study to derive a pediatric abdomen

1 Arbogast K. B., Mong, D. A., Marigowda, S., Kent, R., Stacey, S., Mattice, J., … & Rouhana, S. R. (2005). .
Evaluating pediatric abdominal injuries. (Paper No. 05-0046-O). In: Proceedings of the 19th International Technical
Conference on the Enhanced Safety of Vehicles, June 6-9, 2005, Washington, DC. Available at www­
nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0046-O.pdf
2 Gotschall, C. S., Better, A. I., Bulas, D., Eichelberger, M. R., Bents. F., & Warner, M. (1998). Injuries to children
restrained in 2- and 3-point belts. Annu Proc Assoc Adv Automot Med.; 42: 29–43. .
3 Arbogast, K. B., Chen, I., Nance, M. L, Durbin, D. R & Winston, F. K. (2004).. Predictors of pediatric abdominal
injury risk. Stapp Car Crash Journal,48: 479-494.
4 Chamouard F, Tarriere, C., & Baudrit, P. (1996). Protection of children on board vehicles: influence of pelvis
design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster. (Paper Number
96-S7-O-03). In: Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles,
May 13-16, 1996; Melbourne, Australia, pp. 1063-1075. .
5 Reed, M. P., Ebert, S. M., Sherwood, C.P., Klinich, K. D., & Manary, M. A. (2009, May). Evaluation of the static
belt fit provided by belt-positioning booster seats. Accid.Anal Prev.;41(3):598–607.
6 Reed M. P., Sochor, M. M., Rupp, J. D., Klinich, K. D., & Manary, M. A. (2009). Anthropometric specification of
child crash dummy pelves through statistical analysis of skeletal geometry. J Biomech: 42: 1143-1145.
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