Occupant Diversity in Modelling and Evaluation Related to SoftTissue Neck Injuries in Low Severity Impact
Paper in proceedings, 2013
It is well established that the risk of soft tissue neck injuries (or whiplash associated disorders) is higher for females than for males, even in similar crash conditions. Injury statistics from the mid 1960´s until today all show that females have a higher risk of sustaining such injury than males, ranging from 1.5 to 3 times higher. These injuries arise in one of the most frequent collision types and thus an important societal issue.
Testing and evaluation of automotive systems are essentially determined by crash test dummies representing the 50th percentile male crash test dummy. While this dummy corresponds to a 90th -95th percentile female with regards to stature and mass, it may not be applicable for assessing the biomechanics of females, particularly for injuries resulting from low velocities rear impacts. Females and males have different anthropometry and mass distributions which may influence the interaction of the upper body with the seat backrest and head restraint and thus the injury risk.
In this study the anthropometry and mass distribution of an average female was established. The anthropometry of the 50th percentile female for a rear impact crash dummy model was derived from data published in the scientific literature and data available to the consortium. This data was used to develop a finite element model of an average female dummy EvaRID (Eva – Female, RID – Rear Impact Dummy) and a new loading device called BioRID 50F. Both the numerical and physical models were based on the currently available rear impact dummy of an average male, the Biofidelic Rear Impact Dummy (BioRID) II.
Volunteer tests involving male and female subjects were performed. Analysis of the volunteer tests resulted in dynamic response corridors that were used in the evaluation of the EvaRID model. Initial evaluations of seat performance were also undertaken with the male and female versions of the BioRID II physical test devices. The results show how the design of the seats are sensitive to the occupant mass distributions and, in some cases, resulted in poorer performance when loaded with a smaller and lighter dummy model. Future safety evaluations need to be adjusted to account for different occupant size and gender.