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In France, as in other countries, accident research studies show that the greatest proportion of restrained occupants sustaining severe injuries and fatalities are involved in frontal impact (70% and 50% respectively). In severe frontal impacts with restraint occupants and where intrusion is not preponderant, the oldest occupants very often sustain severe thoracic injuries due to the seat belt. In the seventies, a few cars were equipped in France with load limiters and it was thereby possible to observe a relationship between the force applied and the occupant's age with regard to this thoracic risk. The reduction of intrusion for the most violent frontal impacts, through optimization of car deformation, usually translates into an increase in restraint forces and hence thoracic risks with a conventional retractor seat belt for a given impact violence.

With drivers wearing 3-point seat belts, the head-steering-wheel impact occurs in most serious accidents, so inducing mainly face injuries. In a first part, the authors analyze the injuries observed in a sample of 1180 belted drivers involved in frontal collisions, making a distinction, mainly for facial impacts, between injuries related to the properly so-called face and those to the skull and brain and the different possible lesional correlations. In the second part are presented the results of work carried out in order to define a human face model adaptable to any type of Hybrid II or Hybrid III dummies' heads. The use of this model allows one to elaborate a new protection criterion for the face, destination of which should be to complete the head and skull protection criterion, such as the HIC (or another equivalent criterion which could possibly replace it).

A large number of experiments involving cadavers - including real-world-accident reconstructions - have been performed for the purpose of enhancing the state of knowledge concerning tolerance levels and protection criteria relevant to side-impact conditions. However, the scatter of the findings, as well as the considerable differences in injury severity levels (differences that cannot be accounted for by age differences alone) have limited the conclusions that it was possible to draw from these investigations in terms of criteria, mainly concerning thoracic protection. The major cause of scatter is the considerable differences in skeleton quality between subjects. Analysis of the rib characterization test findings made it possible to define a thoracic resistance index enabling the establishment of a classification of subjects. This index, which was validated with our sample, allowed us to evaluate the pertinence of the various side-impact protection criteria considered.

One studies the conditions in which occurred side impacts having led to death of 369 car occupants. This sample is representative of the population of fatal collisions having occurred on French roads, in 1980. 28 % of killed were victims of collisions against another private car, 34 % struck a fixed obstacle, 21 % undergone a collision against a truck. The other types of collisions account for 17%. The performances to be reached in order to spare an important number of victims are of a high level. This is measured in function of the distribution of impact violences and occupants' ages.

A series of fresh human cadaver and Part 572 dummy tests was performed under different conditions which were comparable to those of real-world accidents. A European car model mounted on a sled was used; a pair of knee-targets was fixed directly to the car body in front of the passenger knees. Test conditions are summarized as follows: human-3-pt-belted cadaver with a sled impact velocity of 50 or 65 kph; 2-pt (thoracic)-belted-cadaver with a velocity of 65 kph, the legs being positioned normally or in an oblique manner. Since the knee-thigh-hip tolerance is related to the shape and duration of the impact pulse, these interactions were the subject of a study. The tolerance to fractures depends to a great extent on the subject's bone condition.

The goal of this paper is to examine the validity of the Crashworthiness Rating Method (part of the New Car Assessment Program -NCAP - created by NHTSA) with reference to real-life accident data. A program was set up to verify the quality of predictive characteristics of vehicle models' real passive safety protection based on 35 mph crash tests against a 0° barrier. The Crashworthiness Rating Method was applied in the French context because seat belt use has been mandatory in France for over 10 years, and we have access to real-life accident files whose size and categories (type of vehicle model, crushed area, obstacle struck, seat occupied, age, and use of seat belt) allowed us to select cases appropriately and thoroughly. Additionally, the vehicle models which are representative of the French vehicle fleet were tested as if they were part of the NCAP.

This paper deals with frontal crash simulations with 3 point seat-belts, in which the conventional anthropomorphic test dummy has been replaced by a fresh unembalmed cadaver. Numerous test conditions have been used. Here are the complete results on the thorax for 31 cadavers in dynamic tests and 7 others in static tests. Specific interest in the thorax comes from the examination of injuries which has shown that, for a normal test, severe injuries are seldom located elsewhere than in the thorax. Methodology, which is the first described, states in particular how the cadavers are prepared with reconstitution of blood pressure and lung inflation and how skeleton strength is characterized. Among the results shown are those for the thorax autopsies, the corresponding seat belt restraint forces, some measurements with dummies used simultaneously and some data on recorded thorax deflections.

Car-pedestrian accidents were selected with reference to criteria like relevance in terms of injury severities representativity and reproducibility aiming to as accurate as possible reconstructions by dummy and cadaver tests. Parameters necessary for performance of these reconstructions were evaluated from the data of accident investigation teams. Preliminary tests were performed by research departments of automobile manufacturers to check the estimated conditions of these accidents before performing their reconstructions. A particular aim was to obtain insights into the mechanisms leading to injuries in pedestrian accidents; more generally reconstructing actual accidents is a privilegied approach to determine human tolerance limits and the corresponding protection criteria on dummies; the injuries resulting from the actual accidents are consequently compared with the data measured on dummies and cadavers in the reconstruction experiments.

This study is related to the modifications of Part 572 dummy for lateral impact, to aid in the evaluation of the injury reducing potential of automotive lateral protection systems. This was done by modifying the rib cage, arms and shoulders of Part 572 so that its impact performance more closely simulates that of a human. According to biomechanical data coming from cadaver testing, the arm was modified by reducing the size of the structural members and increasing the padding of the arm; the mobility of the shoulder was increased in both forward and upward directions. Moreover, the shoulder was modified to become transversely collapsible to a certain extent. The rib cage was redesigned so as to give a more realistic deformation. The measurement of lateral chest deflection was also incorporated into the rib cage design. The frontal impact characteristics of the dummy, both for impact and belts, were left unchanged.