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Past rollover condition testing reported by the author utilized experimental seat belts, a rigid seat and a sitting pelvis Hybrid III mannequin or volunteer to observe dynamic vertical excursion. Other testing in a rollover condition utilized a rigid mannequin molded from a Hybrid III, sitting in a production vehicle restraint system. Application of rigid device in the test allows for simplification of the problem under study, yet limitations in the interpretation of the results. A third test program was conducted combining the rigid device of prior testing into one test, thereby allowing further scientific inference as to the affect of the seat belt restraint system in rollover conditions. Results show that an important factor in the extent of occupant vertical excursion is the kinematics and compliance of the occupant.

A series of controlled experimental programs were conducted for the purpose of improving the motor vehicle rollover protection system. Test results reported in this paper have been previously presented in SAE Paper No.980213 [1]. Experiments tested lap belt restraints utilizing a variety of lap belt geometric and webbing slack conditions. Tests utilized in the series include dynamic and static tests and the use of test mannequins and human volunteers. In the first test program, utilizing a rigid seat, human volunteers were subjected to minus 1.0 Gz acceleration and a 95th percentile Hybrid III mannequin was subjected to minus 5.0 Gz acceleration for a variety of lap belt conditions. A second program utilized a rigid mannequin in production vehicle seats for the purpose of measuring and comparing seat belt system effective slack. Finally, the rigid mannequin from the second test and the rigid seat and lap belts from the first test were brought together and tested.

A controlled experimental program was conducted to determine the response of humans and a human surrogate with experimental lap belt restraints in -Gz acceleration environments. In the program, lap belt anchorage position (belt angle) and belt tension/slack were varied. Human volunteers were subjected to a static -1.0 Gz acceleration for each restraint configuration. A 95th percentile male Hybrid Ill dummy was subjected to a nominal 4.25 m/s (9.5 mph), -5 Gz impact while restrained by each restraint configuration. For the -Gz acceleration, significant changes in occupant head excursion were observed with varied lap belt configurations. In general, less pre-crash belt slack and higher lap belt angles produced significant reductions in occupant vertical excursions. This research provides data for use in evaluating or developing occupant survivability systems for rollover crash environments.