Does unbelted safety requirement affect protection for belted occupants?

Jingwen Hu, Kathleen D. Klinich, Miriam A. Manary, Carol A.C. Flannagan, Prabha Narayanaswamy, Matthew P. Reed, Margaret Andreen, Mark Neal, Chin Hsu Lin

Research output: Contribution to journalArticle

Abstract

Objective: Federal regulations in the United States require vehicles to meet occupant performance requirements with unbelted test dummies. Removing the test requirements with unbelted occupants might encourage the deployment of seat belt interlocks and allow restraint optimization to focus on belted occupants. The objective of this study is to compare the performance of restraint systems optimized for belted-only occupants with those optimized for both belted and unbelted occupants using computer simulations and field crash data analyses. Methods: In this study, 2 validated finite element (FE) vehicle/occupant models (a midsize sedan and a midsize SUV) were selected. Restraint design optimizations under standardized crash conditions (U.S.-NCAP and FMVSS 208) with and without unbelted requirements were conducted using Hybrid III (HIII) small female and midsize male anthropomorphic test devices (ATDs) in both vehicles on both driver and right front passenger positions. A total of 10 to 12 design parameters were varied in each optimization using a combination of response surface method (RSM) and genetic algorithm. To evaluate the field performance of restraints optimized with and without unbelted requirements, 55 frontal crash conditions covering a greater variety of crash types than those in the standardized crashes were selected. A total of 1,760 FE simulations were conducted for the field performance evaluation. Frontal crashes in the NASS-CDS database from 2002 to 2012 were used to develop injury risk curves and to provide the baseline performance of current restraint system and estimate the injury risk change by removing the unbelted requirement. Results: Unbelted requirements do not affect the optimal seat belt and airbag design parameters in 3 out of 4 vehicle/occupant position conditions, except for the SUV passenger side. Overall, compared to the optimal designs with unbelted requirements, optimal designs without unbelted requirements generated the same or lower total injury risks for belted occupants depending on statistical methods used for the analysis, but they could also increase the total injury risks for unbelted occupants. Conclusions: This study demonstrated potential for reducing injury risks to belted occupants if the unbelted requirements are eliminated. Further investigations are necessary to confirm these findings.

Original languageEnglish (US)
Pages (from-to)S85-S95
JournalTraffic Injury Prevention
Volume18
DOIs
StatePublished - May 29 2017

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risk
performance
Safety
Wounds and Injuries
means of transport
optimization
test
parameter
method
system
Seat Belts
data bank
statistical method
computer simulation
deployment
genetics
driver
security
algorithm
simulation

Keywords

  • Crash simulations
  • field data analysis
  • field performance evaluation
  • restraint design optimization
  • seat belt interlock
  • unbelted requirements

ASJC Scopus subject areas

  • Safety Research
  • Public Health, Environmental and Occupational Health

Cite this

Does unbelted safety requirement affect protection for belted occupants? / Hu, Jingwen; Klinich, Kathleen D.; Manary, Miriam A.; Flannagan, Carol A.C.; Narayanaswamy, Prabha; Reed, Matthew P.; Andreen, Margaret; Neal, Mark; Lin, Chin Hsu.

In: Traffic Injury Prevention, Vol. 18, 29.05.2017, p. S85-S95.

Research output: Contribution to journalArticle

Hu, J, Klinich, KD, Manary, MA, Flannagan, CAC, Narayanaswamy, P, Reed, MP, Andreen, M, Neal, M & Lin, CH 2017, 'Does unbelted safety requirement affect protection for belted occupants?' Traffic Injury Prevention, vol 18, pp. S85-S95. DOI: 10.1080/15389588.2017.1298096

Hu, Jingwen; Klinich, Kathleen D.; Manary, Miriam A.; Flannagan, Carol A.C.; Narayanaswamy, Prabha; Reed, Matthew P.; Andreen, Margaret; Neal, Mark; Lin, Chin Hsu / Does unbelted safety requirement affect protection for belted occupants?

In: Traffic Injury Prevention, Vol. 18, 29.05.2017, p. S85-S95.

Research output: Contribution to journalArticle

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