Biomechanics of 4-point seat belt systems in frontal impacts.

摘要: The biomechanical behavior of 4-point seat belt systems was investigated through MADYMO modeling, dummy tests and post mortem human subject tests. This study conducted to assess the effect belts on risk thoracic injury in frontal impacts, evaluate ability prevent submarining under lap using belts, examine whether may induce injuries not typically observed with 3-point belts. performance two types compared that a pretensioned, load-limited, belt. A an extra shoulder "crisscrossed" chest (X4) appeared add constraint torso increased deflection risk. Harness style (V4) loaded body different manner than X4 V4 shift load clavicles pelvis reduce traction across chest, resulting reduction by factor two. is associated 5 500-fold risk, depending one assumes apply concentrated or distributed load. In four six subjects restrained during 40 km/h sled tests, compression zero negative rib fractures were nearly eliminated. Submarining any test subjects. Though lumbar, sacral pelvic noted, they are believed be due artificial restraint environment (no knee bolsters, instrument panels, steering airbags). While show significant potential there still many issues resolved before can considered for production vehicles. These include, among others, effects hard soft neck tissues, interaction inboard farside impacts fetus latch/buckle junctions at centerline pregnant occupants. Work continues Ford Motor Company resolve these issues.