1Transport and Road Research Laboratory, United Kingdom
In a pedestrian accident the severity of injury to different parts of the body varies considerably with respect to the shape of the car front. Consequently for the areas of a car important for pedestrian safety (the bumper, bonnet leading edge, and bonnet top) the protection requirements will also vary considerably according to the car shape.
Existing U.K. proposals for guidelines, specify subsystem testsr that examine the effectiveness of protection at each of these three locations, by using impactors to represent sections of a pedestrian's body. The sub-system test must match the impact energy at each location, which depends on the shape of the car. The mass of the impactor should be the mass which best represents the pedestrian striking the car at that point.
Experimental data on impact energy and effective mass at each phase of impact has been obtained from full scale tests with an adult pedestrian dummy and a range of simulated car shapes. The results are given in this paper, and are discussed with respect to their implication for sub-system testing. They are also compared with mathematical simulation data used for compiling the basic sub-system tests.
The results show that bonnet height strongly influences impact energy for all phases of the impact. Bumper height influences the impact energy for bumper and bonnet leading edge contacts. The effective mass of impact is seen to vary throughout an impact and also with respect to car shape, but suggested values for sub-system impactors are:
Pedestrian protection should be considered at an early stage in the production of a new car. At the design stage, the results in this paper can help in selecting an overall shape and can also be used in conjunction with human tolerances to calculate crush depth and stiffness at the main contact points.