Repeatability of the CRABI 12MO, CRABI 18MO, and Hybrid III 3YO ATD Neck Response During Forward and Rear Facing Frontal Impacts

Principal Investigator: Yun Seok Kang, PhD, The Ohio State University

WHAT WAS THE PURPOSE OF THIS PROJECT?

The pediatric ATD neck consists of a molded neck with a center cable to change neck tension. However, there is limited information on how head-neck response could be affected by different neck cable tension levels (neck tensions). In addition, current ATDs have a stiff connection between the neck and upper thoracic spine, known as the cervicothoracic junction, and it is important to investigate how biofidelic this connection is in the head-neck response.

Previously, we investigated biofidelity and repeatability of a Hybrid III 6-year-old ATD and saw statistically different responses by changing the neck tension. This motivated us to further investigate ATDs representing younger children. We attached the CRABI 12-month-old ATD and Hybrid III 3-year-old ATD to a mini sled to mimic frontal impact scenarios to test the head-neck complex. We ran repeated tests to check repeatability and compared the response to the scaled biofidelity response corridors.

WERE ANY OF THE FINDINGS SURPRISING?

The repeatability for the younger pediatric ATDs ranged from good to acceptable, even with different neck tensions. However, improvements are needed to achieve better biofidelity. This is a significant challenge due to a lack of pediatric biomechanical data and response targets. For this project, we used currently available data to develop a new scaled set of biomechanical response corridors to compare the response from the tested pediatric ATDs.

WHAT ARE THE IMPLICATIONS FOR INDUSTRY?

Many vehicle and car seat manufacturers use ATDs to design, develop, and improve safety systems. Evaluating and understanding ATD repeatability and biofidelity should provide manufacturers with knowledge about how ATDs will perform, potentially leading to further optimized safety systems.

WHAT’S NEXT?

We would like to improve the pediatric ATD neck by working with manufacturers and designers. Different levels of tension in the neck cable or modifications to the stiffness of the cervicothoracic junction might enhance these safety tools.

REPEATABILITY OF THE CRABI — Head and neck motions in a forward-facing configuration for the Hybrid III 3-year-old ATD are shown above.

Co-Investigator

Julie Mansfield, PhD, The Ohio State University

Student

Vincent Schreck, The Ohio State University

IAB Mentors

Allison Schmidt, Britax Child Safety Inc.; Jerry Wang, Humanetics Innovative Solutions Inc.; Russ Davidson, Lear Corporation; Erin Hutter, National Highway Traffic Safety Administration