Comparison of the Q3 and Hybrid III three-year-old dummy head and neck response during side air bag loading.

This paper presents the results of twenty (n=20) tests designed to compare the head and neck response of the Q3 dummy and the Hybrid III 3-year-old dummy subject to loading by a deploying side air bag. In a static test environment, experiments were conducted in two positions using three seat-mounted thoracic side air bags that varied only in the level of inflator output. The instrumentation for both the Q3 and Hybrid III dummies included upper and lower neck load cells as well as head and chest accelerometers and angular rate sensors. Substantial kinematic and kinetic differences were observed due to differences in head geometry and mass, and neck stiffness between the two dummies. The Hybrid III head is 18% heavier than the Q3 and resulted in peak head centre of gravity accelerations significantly lower (p=0.01) than those observed in the Q3. The increased size of the Hybrid III head resulted in more extensive interaction between the deploying air bag and the head as compared to the smaller Q3 head. In tests with air bag loading of the posterior head, this difference in interaction patterns resulted in significantly greater (p=0.01) neck tension in the Hybrid III versus the Q3. In tests with air bag loading of the posterior head, this difference in interaction patterns resulted in significantly greater (p=0.01) neck tension in the Hybrid III versus the Q3. Additionally, under this loading, the stiffer Hybrid III neck resulted in 41 plus or minus 29% higher neck flexion moment compared to the Q3. While the stiffness properties for the Q3 neck are similar in all directions, the Hybrid III neck has preferred anterior-posterior stiffness properties. This difference was observed in tests where lateral loading of the head forced lateral bending in which the Hybrid III recorded a 101 plus or minus 80% higher lateral bending moment compared to the Q3. Although there is considerable uncertainty as to the validity of published injury criteria due to the lack of child biomechanical data, these tests suggest that separate injury criteria are needed for each dummy. (A)