The dilemma of using a shoulder belt force limiter with a three point belt system is selecting a limit load that will balance the reduced risk of significant thoracic injury due to the shoulder belt loading of the chest against the increased risk of significant head injury due to the greater upper torse motion allowed by the shoulder belt load limiter. However, with the use of air bags, this dilemma is more mangeable since it only occurs for non-deploy accidents where the risk of significant head injury is low even for the unbelted occupant. A study was done using a validated occupant dynamics model of the Hybrid III dummy to investigate the effects of a prescribed set of shoulder belt force limits had on head and thoracic shoulder belt force limits had on head and thoracic responses for 48 and 56 km/h barrier simulations with driver air bag deployment and for threshold crash severity simulations with no air bag deployment.(A)
Abstract