ANALYSIS OF THE INFLUENCE OF MOTOR CARS' RELATIVE POSITIONS DURING A RIGHTANGLE CRASH ON THE DYNAMIC LOADS ACTING ON CAR OCCUPANTS AND THE RESULTING INJURIES

摘要

Side collisions of vehicles participating in the traffic are very common road accidents in Poland. In 2013, such collisions amounted to 29% of all the traffic accidents and they were accountable for 31% of the injured and 18% of the killed among all the accident victims. In spite of a decline in the total numbers of road accidents and of the resulting casualties, recorded for more than the recent decade, the percentages of side collisions of vehicles in the traffic and of the resulting casualties in the total figures have been observed to grow. On the other hand, the severity rate of accidents of this type has been remaining for many years on a stable level while it has been decreasing for other vehicle crash types. This shows that the progress in the protection of motor car users from the effects of side impacts is too slow. Therefore, it seems reasonable to carry out research on the processes that take place during side collisions. A research project, expected to facilitate the exploration of the course of some processes in result of which dynamic effects are produced by a right-angle collision of two motor cars on car occupants, has now been in progress at the Automotive Industry Institute (PIMOT) in Warsaw. Within the project, six crash tests were performed with the use of 12 passenger cars of the same make and model. At each test, the front of car A crashed into the left side of car B. The pre-impact speed of car A was about 50 km/h and it was twice as high as that of car B. At successive tests, different places on car B were struck by car A. In each car, a Hybrid III test dummy was placed on the front right seat and a Hybrid II dummy was placed on the front left seat. The measuring systems used made it possible to determine the following: (1) dynamic interactions between the cars; (2) lateral displacements of the torsos and heads of the dummies placed on the front car seats; (3) dynamic loads acting on dummies' heads and torsos; (4) relations between the force applied to car B and the dynamic loads acting on the occupants of that car. The paper includes test results, thanks to which the time histories of the force acting on the impacted car as well as the effect of this force on the displacements and accelerations of the test dummies could be presented. An analysis of the test and computation results has shown that the location of the place of impact on car B has a considerable influence on the loads received by the car occupants. The knowledge of the dynamic loads acting on the occupants of front seats of car B makes it possible to predict the likelihood and scope of injuries to the occupants depending on the relative positions of the car during a collision. The test and analysis results presented herein will be used for improving the construction of the system of individual protection of motor car occupants, including a system to restrain lateral displacements of car occupants during a side collision.