Simulation of car-pedestrian accident for evaluate car structure

A new computer system and human body model to simulate the pedestrian road accidents involving vehicles were developed for evaluating vehicle structure and pedestrian injury. The aim of the simulation system is to predict the dynamic behavior of pedestrians and influence of car shape and structure on the pedestrian injury. To evaluate actual vehicle shapes and structures, this system carries simulations into an FEM environment. And new types of human body models were developed for the simulation. The character of human body model is to have a self-scaling modeling program for any pedestrian weight and height and particular joint characteristics obtained by the PMHS test. This paper describes the content of the simulation system and presents some results from the simulations. lNTRODUCTION Pedestrians account for approximately one-third of those killed by traffic accident in Japan. There has been a desperate call for more effective structures of automobiles to reduce traffic accident casualties drastically. In recent years, responding to those demands, Honda proposed the ASV concept. And EURO-NCAP pedestrian tests are held using EEVC impactor method. To further enhance this safety improvement trend, it has been considered necessary to establish a simulation system for evaluate car structure and for analyze the phenomenon of car pedestrian accidents is desired. The authors successfully developed one simulation system to reveal pedestrian body behavior. The major feature of the technique is having an analytical dummy of which behavior corresponds to the pedestrian PMHS test data. And it moves in the environment of FEM. This technique can evaluate the vehicle structure and identify phenomenon in car-pedestrian accident. The new simulation system made it possible to comparatively study the influence of automotive body configuration on pedestrians, which could not otherwise be performed by impactor tests. This paper describes system description and examples of calculations conducted with mass production vehicles. Simulation System 1. Analytical Dummy Model Figure 1. Ellipsoid Dummy The dummy model described in this paper has 15 ellipsoids segments for each human body. And each geometric shape, center of gravity, inertia moment are created automatically by the program adjusting weight and height of every physiques. Physical properties of joint that connect adjacent segments were assumed to be common for every physique. The geometrical properties, center of gravity, inertia moments were based on the measurement results of 32 body measurements used by the GEBOD. This program was capable of creating various dummy models which differ in terms of height, weight, sex, and age (Figure 2.). Also standing initial positions and postures remain variable. It is necessary to determine new joint character in the process of corresponding with PMHS test data. Figure 2. Child, Female, Male dummies