Occupant injury in side impacts with roadside hardware

In an effort to reduce injury risk to occupants involved in vehicle crashes, government regulations require all production vehicles to be evaluated in standardized frontal and side impact crash tests before they are sold in the United States. Similarly, roadside safety hardware like guardrails, guardrail terminals and luminaire supports are evaluated using full-scale crash tests. The present practice of predicting injury risk in full-scale crash tests is based on accelerometer readings from an appropriate Anthropomorphic Test Dummy (ATD) seated inside the crash vehicle. While ATDs are routinely used in automotive crash tests, difficulty in controlling the movements of the ATD in high velocity impacts has limited their use in crash tests. The present study aims at understanding injury causation in side impact collisions with roadside hardware and determining a quantitative relationship between the ATD based injury measures and the collision characteristics.; Relationships between ATD injury criteria and vehicle crash parameters were explored by performing a series of side impact simulations of a Ford Taurus vehicle model with a simple guardrail terminal model, using LS-DYNA3D finite element code. A finite element model of the Side Impact Dummy (SID) was placed in the vehicle model to obtain occupant injury values in 24 sled test and 35 in-vehicle side impact simulations.; The results of the study indicated that the SID kinematics are independent of the vehicle. The SID interacts only with the door and the struck object. The rest of the vehicle does not affect the occupant injury process. The timing of impact of the SID with the vehicle interior is also very important. Very different injury measures can be obtained with the same vehicle---hardware interaction, depending on the point on the velocity profile of the door and the struck object where the SID contacts, and the point where it reaches the common velocity.; The data obtained from all the in-vehicle tests was analyzed and a simple equation for predicting the Thoracic Trauma Index (TTI) without the use of an ATD in the crash vehicle was developed.