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The responses of the THOR and the Hybrid-III ATDs to head and neck loading due to a deploying air bag were investigated. Matched pair tests were conducted to compare the responses of the two ATDs under similar loading conditions. The two 50th percentile male ATDs, in the driver as well as the passenger positions, were placed close to the air bag systems, in order to enhance the interaction between the deploying air bag and the chin-neck-jaw regions of the ATDs. Although both ATDs nominally meet the same calibration corridors, they differ significantly in their kinematic and dynamic responses to interaction with a deploying air bag. The difference between the structural designs of the Hybrid-III's and the THOR's neck appears to result in significant differences in the manner in which the loads applied on the head are resisted.

While the Hybrid III anthropomorphic test device (ATD) family has experienced a lengthy period of development, and is an essential part of vehicle safety regulation, several issues associated with the ATD's head/neck design and the neck dynamic response due to airbag loading have been identified. As a result, the response of the Hybrid III neck under a number of airbag loading conditions could be an “artifact” of the ATD and not representative of the live human. One area of concern relates to the method of incorporating the human neck muscles into the neck response and how this affects the out-of-position (OOP) tests mandated in the new FMVSS 208. The results of a series of sled and OOP tests are presented in this paper to elaborate on the nature and the magnitude of the ATD's neck response “artifact”. In addition, the complication associated with balancing in-position and OOP requirements as a result of this “artifact” is highlighted.

The Hybrid III family of dummies is used to estimate the response of an occupant during a crash. One recent area of interest is the response of the neck during air bag loading. The biomechanical response of the Hybrid III dummy's neck was based on inertial loading during crash events, when the dummy is restrained by a seat belt and/or seat back. Contact loading resulting from an air bag was not considered when the Hybrid III dummy was designed. This paper considers the effect of air bag loading on the 5th percentile female Hybrid III dummies. The response of the neck is presented in comparison to currently accepted biomechanical corridors. The Hybrid III dummy neck was designed with primary emphasis on appropriate flexion and extension responses using the corridors proposed by Mertz and Patrick. They formulated the mechanical performance requirements of the neck as the relationship between the moment at the occipital condyles and the rotation of the head relative to the torso.

A comparison of the NHTSA advanced dummy, THOR, and the Hybrid III dummy is presented in this paper, based on their performance in four vehicle barrier tests, six HYGE sled tests and twenty two pendulum chest–impact tests. Various time–histories pertaining to accelerations, angular motions, deflections, forces and moments are compared between the two dummies in light of their design difference. In general, in the vehicle crash tests, the resultant head acceleration and chest deflection in THOR are greater than those in the HYBRID III. The shear, axial force and lateral moment in THOR's lumbar are less than those in the Hybrid III in frontal impacts. The differences in the head/chest acceleration and chest deflection could be due to the differences in the construction of the neck and the thorax of the THOR when compared to those of the Hybrid III. The THOR and the Hybrid III have the same level of repeatability in the rear impact sled tests.