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A study was conducted to obtain basic data on frontal crash deformation of compact cars (mini-sized motor vehicle). A compact car is lighter in weight than the other type of passenger cars due to the category size. In case of a ordinary passenger vehicle to compact car crash, it was assumed that the deformed value which leads to a higher speed as a barrier equivalent velocity becomes bigger than that of a ordinary passenger vehicles. For analyzing a frontal crash characteristics of compact cars, three experimental collisions which compact cars were crashed to a frontal full-lap barrier with velocities of 85 and 100 km/h and half-lap offset barrier with velocity of 85 km/h were performed. This study deals with the process of frontal deformation and the energy absorption diagram of the compact car body, and these are discussed to compare with the publicized data on small passenger vehicles.

This paper describes the method to improve the energy absorption characteristics during the vehicle frontal collision. The method is to control the collapse phases of the members constituting the vehicle body and to increase collapse force of a member. This phase-control can be accomplished by superimposing the crest of the collapse force curve, which one member causes, on the trough of any other members'. The bulkheads installed in the members are useful. to control the phase and to increase the collapse force. Numerical analysis and experiment of a vehicle collision show that the control leads to the improvement of energy absorption characteristics and load transmission efficiency.

Improvements for pedestrian head protection in a car-pedestrian accident have been discussed in several countries. Test methods for evaluating head protection have been proposed, and most are sub-systems using rigid headforms with or without headskin. In those tests, HIC is used as a criterion for head protection. This paper discusses the test conditions and requirements of the headform impact test. The influence of different test conditions and their importance on head impact test requirements, were verified. The primary items cited are as follows: (1) The results of the rigid headform were similar to that of the human cadaver skull in cases without skull fractures. Consequently, the rigid headform can be used for the impactor simulating a condition without skull fracture. (2) In the cases of HIC≤1000, the force-deformation curves of the hoodtops showed similar characteristics with maximum dynamic deformations over 60mm. (3) Impactor mass affected the maximum acceleration and HIC.

This paper is a compilation of the present state of research in Japan relating to offset frontal crashes using a deformable barrier. It contains an analysis of actual accidents in Japan, accident reproducibility tests implemented using vehicles as examples of representative accidents and a consolidation of the results of studies of reproductive techniques reproduced using a deformable barrier based on the accident reproducibility test results. In the deformable barrier tests, in the case of changes in the offset ratio, barrier face form, barrier face rigidity, crash velocity and the like, the degree of change of vehicle behavior, dummy behavior, vehicle deformation and the dummy injury values have been compared with the results study of accident reproducibility tests. From these results, basic data was obtained relating to test methods for offset deformable barrier collisions.

To investigate the human head impact tolerance in terms of changes in vital functions, a series of head impact experiments was performed using live monkeys, which are morphologically analogous to humans. To find a causal relationship between the impact and changes in vital functions, three kinds of experimental conditions were used: translational acceleration impact and rotational acceleration impact (both using a head restraint mask with broad contact area), and impact of the unrestrained head against a padded flat surface. The results indicated that the concussion, cerebral contusion and skull fracture in the monkeys depended on: i) the translational and rotational acceleration impact; ii) the contact area of the impact; iii) the amplitude and duration of the imposed head acceleration*; iv) the direction of the impact region (whether frontal or occipital).