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Child dummies used in certification dynamic tests have not been improved since their marketing and their approval as European regulation dummies. Their main shortcoming lies in a too high and therefore unrealistic stiffness of the torso front part. The paper addresses a study carried out in the aim of solving this problem. It includes two parts: in a first section, the changes brought to the dummy torso and intended to improve its biofidelity and to reduce stiffness drastically are described. In order to reach such an objective, the lower part of the upper torso was remodelled; the pelvis profile was redefined and the geometrical and mechanical characteristics of the foam used for the abdominal insert were changed. The results obtained using two transducers installed in the abdominal section are then presented. The measurement principle of the first transducer consists in a pressure measurement, and the principle of the second one in a load measurement.

This paper presents comprehensive dorsiflexion responses and tolerances obtained from two types of dynamic tests on whole cadavers conducted at the Renault/PSA Laboratory of Accidentology and Biomechanics (LAB): sled tests and sub-system tests. In all the experiments (on whole cadavers), forces and moments within the ankle joint were accurately measured by means of a custom-designed 6-axis load cell implanted in the tibia, leaving all surrounding musculature intact. The results derived from both the sled tests and the subsystem tests are very similar. Moment-rotation curves are provided for the ankle joint. The force in the Achilles tendon which is not directly measured is calculated using the forces applied to the foot and the forces measured in the tibia.

The anatomical dimensions, inertial properties, and mechanical responses of cadaver leg, foot, and ankle specimens were evaluated relative to those of human volunteers and current anthropometric test devices. Dummy designs tested included the Hybrid III, Hybrid III with soft joint stops, ALEX I, and the GM/FTSS lower limbs. Static and dynamic tests of the leg, foot, and ankle were conducted at the laboratories of the Renault Biomedical Research Department and the University of Virginia. The inertial and geometric properties of the dummy lower limbs were measured and compared with cadaver properties and published volunteer values. Compression tests of the leg were performed using static and dynamic loading to determine compliance of the foot and ankle. Quasi-static rotational properties for dorsiflexion and inversion/eversion motion were obtained for the dummy, cadaver, and volunteer joints of the hindfoot.

Very few finite element head models have been validated as required before being used to study brain injury mechanisms. This paper deals with the validation study of a 3D head model [1] against five cadaver tests [2]. It evaluates the current model ability to simulate brain responses and draws the research lines to improve it. Velocities on the closed rigid skull model were fixed to duplicate experimental applied loads. Validation parameters were constituted by three intra-cranial accelerations, three epidural pressures and in two cases, two extra pressures in the ventricles. The model response matched experimental results in terms of trend but presented significant oscillations. Moreover, there was a shift between experimental and numerical pressure curves. Brain material damping was introduced but numerical oscillations were slightly reduced.

In view of the lack of data concerning child protection, an accidentological and experimental work was engaged. The goal of this international research involving experts from seven countries was two-fold: In one hand, to establish protection principles, gathering and analysing real crashes involving restrained children. In the other hand, to identify and to quantify injury mechanisms in order to increase knowledge on child tolerances. To realize this second part, real crash reconstructions were performed, in order to correlate observed injuries with recorded parameters on dummies. This paper mainly presents four real crashes with the corresponding reconstructions. A special analysis of injury mechanisms in relation with their respective pertinent parameters is then proposed.

A new approach has been developed to facilitate the measurement of head angular acceleration in automobile crash tests. It consists of two parts: an array of 12 linear accelerometers mounted in a Hybrid III dummy head and an electronic signal processor mounted on the dummy spine. The accelerometer outputs are led to conventional data acquisition equipment and also to the signal processor which digitizes the raw acceleration signals, stores them, and computes the 3-D angular acceleration. This acceleration and the 3-D linear acceleration of the head c.g. are available in real time or post test. The equipment has been evaluated on a mini-sled, with various configurations of head loading and kinematics, and also in Hyge sled tests performed at 40 km/h with a 3 point belted Hybrid III dummy. The angular accelerations returned by the signal processor in both test settings corresponded closely to those computed off-line from the raw data.

The European Side Impact Dummy “EUROSID”, and the Sid Impact Dummy “SID” were extensively tested in the frame of an experimental program conducted by the C.C.M.C. in Europe. The principal objective of this study was the evaluation of the biofidelity of both dummies according to impact response requirements selected by the ISO/TC22/SC12/WG5 experts, these requirements being, at the present the best and most updated technical informations available to assess the biofidelity of a dummy in side impact. The test matrix comprised 40 impactor tests, 75 free fall tests and 7 sled tests. Each dummy region covered by ISO requirements was tested. In this paper the performance of EUROSID and SID dummies are, on the basis of available results, compared with human response data proposed by ISO.

In order to obtain data about human head tolerance, the APR Laboratory of Biomechanics has developed a specific methodology for volunteer boxers. These ones are used because they expose themselves, in their normal body activities, to direct head impacts similar in nature to those experienced by vehicle occupants under crash conditions. This paper describes the specific experimental technique that permits association of the severity of the blows, measured in terms of physical parameters, to corresponding physiological effects, measured in medical terms.

Although the neck is one of the least frequently injured body regions, it does play a considerable role in the solicitations of the head in side impact. It can, in fact, be said that the kinematic and dynamic conditions that govern, for instance, a head impact against a vehicle structure depend on the cervical segment. With a view to characterizing such conditions, i.e. head and neck responses, the LPB-APR conducted a research program including sled tests involving cadavers. These tests were conducted at a low and high G-level sled deceleration, respectively, with the low-violence tests being carried out following collaboration with the Naval Biodynamics Laboratory (New Orleans). Such tests enable direct comparison between volunteer data and cadaver data. The scope of this paper is to present a synthesis of the data obtained from LPB-APR low and high G-level tests, including, in particular, data obtained from new high severity tests.

Children are often involved in automotive accidents especially as car occupants. Their protection presents particular problems in the first years of life, due to large changes in their morphology and behaviour. The aim of this paper is to contribute towards the development of a better evaluation of the child's tolerance to impact. Car accident investigations are analysed to bring information on injury mechanisms and severities. Free fall accidents are other sources of data used to correlate injuries with impact conditions. Theoretical analysis is considered for extrapolation of experimental data obtained from adult humans and animal surrogates. Then crash simulations with child cadavers and primates restrained in child seats are analysed and the estimation of tolerance levels for children is discussed.

Experimental crash data are examined to determine how vehicle rigidity influences seat belt operation. Total occupant braking distance is maximized when a vehicle has high frontal deformation, as belt loading occurs at impact. However, for any given vehicle optimum conditions occur when: 1. Dead time between impact and belt loading is minimized. 2. Seat belt webbing characteristics are matched to vehicle structure to use maximum available braking distance.