Updated chest injury criterion for the THOR dummy

Trosseille, Xavier<sup>1</sup>; Baudrit, Pascal<sup>2</sup>

Affiliations

Abstract

Anthropomorphic crash test dummies are designed to predict the risks of injury in automotive crash conditions. These dummies must therefore measure parameters that make it possible to calculate a metric related to injury mechanisms. This metric must evaluate the risk of injury whatever the solicitation, in a range covering all the solicitations arising in a crash. More specifically for a frontal impact, the risk of chest injury associated with this criterion must be the same, whatever the contributions of the belt or the airbag load paths. The objective of this paper is to develop such a criterion for the chest.

Several thoracic criteria were proposed by Poplin in 2017 for the THOR dummy, based on the measurement of the 4 3D deflections of the thorax. Unfortunately, for the sample studied, these criteria did not predict the risk of rib fractures better than the central deflection measured on an Hybrid III. The in-depth analysis of the sample showed that the sample configurations were too similar and that the deflection range was too small. Additional tests were added to the Poplin sample, which diversified the types of restraint systems and increased the extent of deflections. A new analysis was performed on this sample.

A new criterion was proposed. This criterion is a linear combination of the maximum value of the 4 chest resultant deflections and the absolute value of the difference of the upper right and left deflections. A risk curve was then constructed based on this criterion and age.

The consistency of the results of the new tests performed with the THOR dummy was assessed against the identical tests performed on the Hybrid III dummy. Similarly, the consistency of the injury assessments between the new tests and those of the initial sample was carefully studied. The results of these analyses confirmed the relevance of the added data. If the statistical methods used have shown the best performance of the new criterion, it has been optimized on the sample used and must be validated on external data. This could be verified on some data from the bibliography and further tests are planned to confirm it.

The use of an expanded test sample allowed to successfully develop a new thoracic criterion for the THOR dummy. It better predicts the risk of rib fractures, while being more consistent with crash investigation findings related to the age effect and the balance between the seat belt and the airbag. This paper brings new experimental data and analysis to improve the ability of the THOR to better predict the risk of rib fractures as a function of age.

Links

URL: http://indexsmart.mirasmart.com/26esv/PDFfiles/26ESV-000236.pdf

Cited Works (9)

Year	Entry
2005	Kent R, Lee S-H, Darvish K, Wang S, Poster CS, Lange AW, Brede C, Lange D, Matsuoka F. Structural and material changes in the aging thorax and their role in crash protection for older occupants. Stapp Car Crash J. November 2005;49:231-249. SAE 2005-22-0011.
2003	Mertz HJ, Irwin AL, Prasad P. Biomechanical and scaling bases for frontal and side impact injury assessment reference values. Stapp Car Crash J. 2003;47:155-188. SAE 2003-22-0009.
2012	Luet C, Trosseille X, Drazétic P, Potier P, Vallancien G. Kinematics and dynamics of the pelvis in the process of submarining using PMHS sled tests. Stapp Car Crash J. October 2012;56:411-442.
2005	Lebarbé M, Potier P, Baudrit P, Petit P, Trosseille X, Vallancien G. Thoracic injury investigation using PMHS in frontal airbag out-of-position situations. Stapp Car Crash J. 2005;49:323-342. SAE 2005-22-0015.
2000	Crandall J, Kent R, Patrie J, Fertile J, Martin P. Rib fracture patterns and radiologic detection: a restraint-based comparison. In: 44th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 2-4, 2000; Chicago, IL.
2015	Uriot J, Potier P, Baudrit P, Trosseille X, Richard O, Douard R. Comparison of HII, HIII and THOR dummy responses with respect to PMHS sled tests. In: Proceedings of the 2015 International IRCOBI Conference on the Biomechanics of Injury. September 9-11, 2015; Lyon, France.435-451.
2014	Davidsson J, Carroll J, Hynd D, Lecuyer E, Song E, Trosseille X, Eggers A, Sunnevang C, Praxl N, Martinez L, Lemmen P, Been B. Development of injury risk functions for use with the THORAX demonstrator: an updated THOR. In: Proceedings of the 2014 International IRCOBI Conference on the Biomechanics of Injury. September 10-12, 2014; Berlin, Germany.359-376.
2003	Petitjean A, Baudrit P, Trosseille X. Thoracic injury criterion for frontal crash applicable to all restraint systems. Stapp Car Crash J. 2003;47:323-348. SAE 2003-22-0015.
2008	Trosseille X, Baudrit P, Leport T, Vallancien G. Rib cage strain pattern as a function of chest loading configuration. Stapp Car Crash J. 2008;52:205-231. SAE 2008-22-0009.

Cited By (2)

Year	Entry
2022	Brumbelow ML, Jermakian JS, Arbelaez RA. Predicting real-world thoracic injury using THOR and Hybrid III crash tests. In: Proceedings of the 2022 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2022; Porto, Portugal.264-287.
2023	Östh J, Nylund M, Olofsson N, Iraeus J, Jakobsson L. Assessment of THOR-50M thoracic injury criteria by population-based accident reconstructions. In: Proceedings of the 2023 International IRCOBI Conference on the Biomechanics of Injury. September 13-165, 2023; Cambridge, United Kingdom.882-894.