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Technical Paper

Model for Drivers' Perception of Vehicle Performance

A driver's preference for one of two different vehicle models that have the same measurable acceleration may be explained by complicated factors such as styling, NVH or ergonomics. If the vehicles have identical appearance but different levels of engine tune, discrimination would probably be due to the measurable difference in performance although other factors cannot be entirely discounted. If however, the assessment is made of vehicles with identical appearance and identical performance then any preference is attributable to an area of human assessment that has been termed subjective performance. This paper discusses the first step in a qualitative approach to the analysis of driver perception of vehicle performance and more specifically investigates subjective performance. The proposed model ascribes distinct components such as induced and perceived performance to the total subjective performance rating.
Technical Paper

Correlation Between Thoracic Lesions and Force Values Measured at the Shoulder of 92 Belted Occupants Involved in Real Accidents

The 3-point static belts that are installed in Renault and Peugeot vehicles are equipped with a force limiter near the upper anchorage. This system is made up of several bands of textiles that tear successively for the increasing levels of force exerted by the occupant. One can thus associate, for each person in the accident, the degree of the thoracic AIS and the value of the support force, expressed in daN. This relationship is established for 92 belted occupants who were involved in frontal impacts. In addition it is indicated which are the distributions of impact violence parameters incurred and which are the distributions of ages in order to determine the statistical meaning of the required results. The levels of tolerance observed in this sample are compared to thoracic injuries observed on belted cadavers exposed to equivalent violent impacts.
Technical Paper

Belted or Not Belted: The Only Difference Between Two Matched Samples of 200 Car Occupants

This study aims at determining, with the maximum precision, the performance of the 3 point safety belt in different accident configurations, and more particularly in frontal collisions. For this purpose, two matched samples were taken from a file of 3000 accidents, analysed by a multidisciplinary study group. These samples of 100 front seat occupants wearing seat belts, and 100 not wearing seat belts were made up in such a manner that, for every belted occupant, corresponds an occupant not wearing a belt, the one and the other being in equivalent circumstances, using the following factors: Make and type of the vehicle Seat occupied Age (as far as possible) Direction of impact Violence of the impact (same class of ▵V and mean γ) Possible intrusion of passenger compartment Possible overload caused by a rear seat occupant Using this method of comparison, one can appreciate the effectiveness of the 3 point belt and explain the variations of effectiveness that appear in normal case studies.
Technical Paper

Conditions Required to Avoid Being Killed in Cars in Side Impact

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.
Technical Paper

Reconstruction of Actual Car-Pedestrian Collisions with Dummy and Cadavers

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.
Technical Paper

Occupant Velocity Change in Side Impact Method of Calculation-Application to a Sample of Real-World Crashes

So far, analysis of real-world crashes has not made it possible to evaluate the occupant change of velocity in side impact. This change of velocity is the most pertinent of the lateral-collision violence parameters when occupants are exposed to intrusion by car bodies. The present paper describes a method for calculating this parameter, and includes a description of the data that must be collected concerning real-world crashes in order to enable its application. The validity of this method is demonstrated by its application to a series of experimental collisions. The results are highly correlated to the values resulting from the integration of the accelerations found for the pelvis and thorax. The method is then applied to 60 real-world car-to-car side collisions from the accident survey.
Technical Paper

Influence of Mass Ratio and Structural Compatibility on the Severity of Injuries Sustained by the Near Side Occupants in Car-to-Car Side Collisions

In 1344 car-to-car side collisions, the risk of serious or fatal injury to the occupants of struck vehicles seem to increase proportionally to the difference in mass ratios in favor of the striking vehicle. However, in-depth analysis of 63 collisions during which the impact occurred on the side panel of the passenger compartment reveals that the difference in mass ratios is not the principal determinant of injury severity. The frequency and severity of injuries correlates better with the amount of intrusion of the side panel, a type of intrusion which occurs almost systematically, and even at low impact speed, when the bumper and structure in front of the side rail of the striking car override the rocker panel of the struck car.
Technical Paper

From Three-Years-Old to Adult Size - How to Ensure Child Protection in Automobile Accidents

Safety of children as car occupants raises a specific problem: it is necessary to take into account two factors which are particular to them: their very fast growth and their behavior, which corresponds to a need for movement. An analysis of statistical and accidentological data, points to the fact that whereas traffic accidents account for 25 % of adult deaths, they account for nearly 50 % of deaths for children (all kinds of road-users). Measures were adopted in France; such as the obligation for children of less than 10-years-old to travel on rear seats of cars and the definition of an homologation procedure for children restraint devices, with the aim of limiting the consequences of these accidents. The most common restraint devices look like little individual seats and are designed to protect young children (less than 3-years-old). Recently, new restraint devices, called “cushions”, were developed.
Technical Paper

Field Facial Injuries and Study of Their Simulation with Dummy

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).