A Study of Kinematics of Occupants Restrained with Seat Belt Systems in Component Rollover Tests 2007-01-0709

An experimental study was conducted using a dynamic rollover component test system (ROCS) to study the effects of activating a pyro-mechanical buckle pre-tensioner and an electric retractor on the driver and front right passenger head and pelvis excursions.

The ROCS is a unique system capable of producing vehicle responses that replicate four distinct phases of a tripped rollover: trip initiation, roll initiation, free-flight vehicle rotation, and vehicle to ground contact. This component test system consists of a rigid occupant compartment derived from a mid-size SUV with complete 1st row seating and interior trim, a simulated vehicle suspension system and an elastic vehicle-to-ground-contact surface. The ROCS system was integrated with a Deceleration Rollover Sled (DRS). Dynamic responses of the ROCS system, including both the rigid compartment and occupant, were measured and recorded. A brief discussion regarding the similarities of the vehicle kinematics generated by a full vehicle curb trip test to that of the ROCS test performed for this study is given.

A total of 15 tests were conducted using Hybrid III anthropomorphic test devices (ATDs) of various sizes: 5th, 50th with seated and standing pelvis and 95th percentile ATDs. The ATDs were placed in the driver and 1^st row passenger seating positions and restrained by belt systems. A standard 3-point seat belt system with a combination of a buckle mounted pyro-mechanical pretensioner and a motorized electric retractor were used to generate seat belt tension. The ATD's dynamic head and pelvis displacement, head to vehicle interiors contact and seat belt loads were recorded and compared. High speed digital cameras were used to record the ATD and vehicle kinematics.