Research Papers

Design of a Seat Safety System to Reduce Occupant Injury from Rear End Collisions

Filename Mansour.pdf
Filesize 634 KB
Version 1
Date added June 6, 2010
Downloaded 1 time/fois
Category 2010 CMRSC XX Niagara
Tags Session 5A
Author/Auteur Rami Mansour, Douglas P. Romilly

Abstract

Rear end collisions account for nearly 30% of all vehicle impacts making them the most common type. These types of collisions have been shown to result in an overall societal cost of approximately $9 billion annually in the United States alone. This takes into account a vast range of costs, from injury claims to lost wages. Soft tissue injury to the neck (i.e. “whiplash”) is typically associated with this type of collision due to the occupant dynamics of the passengers in the struck vehicle. At low relative impact velocities, whiplash-type injuries are known to occur but are typically attributed to: 1) improper seat adjustment, 2) an “out-of-position” event, or 3) a low injury threshold due to age, gender, etc. In high impact collisions, both whiplash and occupant ejection can take place, the latter placing far greater risk of injury not only to the front seat occupant, but also to any rear seat passengers as well. In 2007, 19 people were killed in rear end collisions in British Columbia alone. The automobile seating system is the predominant safety device employed to protect the occupant during these types of collisions. Several supplemental safety systems have been developed which focus on the head restraint and the seat back, however the seat base has remained relatively unexamined. The goal of this project is to develop a supplemental safety system for the automobile seat that can remove sufficient kinetic energy from the system before it can be utilized to dynamically load the occupant during a rear end collision. Finite element models produced in LS DYNA have been constructed and used to compare occupant dynamics from both low speed and high speed collisions to accepted neck injury criteria. The relationships between energy levels transmitted to the occupant, the occupant dynamics, and how they affect the neck injury criteria assessed values have been examined. Deformable structures are being investigated as a potential means of absorbing transmitted energy destined for occupant loading. Preliminary results show a promising correlation between absorbed energy within the seat base and a reduction of injury potential to the passenger. Successful implementation of such a supplemental seat safety system should contribute substantially to increasing occupant safety in both low and high speed rear end collisions where severe injury and fatalities may have previously occurred.

Rami Mansour and Douglas P. Romilly