Evaluation of Occupant Loading in Low- to Moderate-Speed Frontal and Rear-End Motor Vehicle Collisions 2019-01-1220
Low- to moderate-speed vehicle collisions are common roadway occurrences and often sources of injury complaints. Prior studies have analyzed occupant kinematics and human injury risk in low- to moderate-speed collisions with various vehicle vintages. Updated vehicle interior designs and occupant protection devices reflect efforts toward optimizing occupant kinematics and reducing occupant loading and injury potential. Evaluation of occupant loading during low- to moderate-speed collisions in late-model vehicles is limited. To address this gap, four full-scale crash tests were conducted to assess occupant motions and loading during inline frontal and rear-end impacts. In each test, both vehicles were late-model, mid-sized sedans occupied by instrumented Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) restrained with a lap-and-shoulder belt in the driver seats. The vehicles were instrumented with accelerometers, and vehicle and occupant kinematics were recorded by real-time and high-speed video cameras. The tests involved aligned front-to-rear bumper collisions at closing speeds ranging from approximately 5 mph to 21 mph. Head accelerations, upper and lower neck forces and moments, chest accelerations, lumbar spine forces and moments, pelvic accelerations, and femur loads were measured for each ATD, in addition to lap and torso belt loads. Spinal load data and femur load data were evaluated to understand the loading environment responsible for generating the recorded body loads. Spinal and femur loads were additionally compared to various activities of daily living (ADLs) and established injury assessment reference values (IARVs). Evaluation of the recorded and calculated responses of the ATDs established that the loads and moments generated during these low-to-moderate speed collisions were far less than accepted IARVs. Furthermore, the spinal loads and moments demonstrated characteristics of inertial loading with similar timescales as common daily activities and, in many cases, were of magnitudes less than or comparable to loads generated by volunteers performing volitional and non-injurious activities.
Megan E. Toney-Bolger, Ian C. Campbell, Bruce D. Miller, Mathieu S. Davis, Jacob L. Fisher