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This paper describes the behavior of a driver side occupant restrained by airbag system on a passenger vehicle at a frontal barrier crash. In order to secure effective occupant protection at collisions, it is necessary to conduct close examination into the movement of steering system due to the rearward movement of dashboard as well as vehicle deformation characteristics, generally for vehicles whose crash space at engine compartment is small. The authors examine the influence of these two parameters on occupant injury indices using MADYMO 2D computer simulation program. As a result, it is found important to model the axial collapse and the rotation of steering system in the vertical plane caused by dashboard deformation, in order to achieve good correlations between experiment and simulation. It is demonstrated.

The capability to predict the response of a vehicle body structure to frontal barrier crash is examined by a vehicle model represented by various lumped mass and non-linear resistance systems from that of one dimensional with minimal degrees of freedom to these of two dimensions and several degrees of freedom. Comparison between numerical calculation and full scale experiment demonstrates that on even a simple representation, the calculations are in good agreement with the experiment. Several methods of obtaining the resistance characteristics based on full scale experiments and quasi-static component crush testing are also presented. Further, distinctive characteristics and subjects to be considered of front wheel drive vehicle compared with front engine rear wheel drive one on passenger compartment integrity and occupant restraint performance are discussed.

This paper presents a practical method to predict a quasi-static barrier load which causes an automobile body structure to collapse. The analytical methods proposed so far on such a crushing problem are generally based on the analytical theory including nonlinearities in material behavior and geometry. This paper describes an analytical method using finite element techniques based on the above-mentioned theory with the contact effect on the interaction between the body structure and the barrier taken into consideration. The computer program for the analysis is based upon the load incremental method. In order to check the validity of the present method, comparison between numerical calculations and experiments is made on both simple models and actual body structures subjected to a crushing barrier load at the roof and the rear end, separately.

Deceleration data of vehicle occupant compartment contain fundamental information related to structural integrity and vehicle/occupant interaction as well. This paper describes the selection of filter characteristics relevant to identification, from noisy accelerometer data on the frontal impact, of the underlying crash pulse shape to be used as an input to analytical simulation model or as a loading condition to sled test. By comparing the response of occupant to full scale experiment among those by numerical calculation, where the occupant is represented by a two-dimensional five mass mathematical model, stimulated by vehicle deceleration processed through filter with various characteristics, the appropriate filter characteristics are discussed in relation to HIC (Head Injury Criteria) and the displacement of the occupant.

The rotational behavior of the vehicle in the vertical plane at frontal collision against a flat barrier often plays an important role with respect to an evaluation of passenger compartment integrity and occupant protection. An analytical method to examine the degree of influence of vehicle front end parameters, both on the behaviour of the vehicle and its occupant, is presented, employing a two-dimensional finite element vehicle model and a two-dimensional lumped-mass occupant model. The feasibility of the method is discussed by comparing the calculated results with the experimented ones, in relation to the behaviour of passenger compartment and its occupant injury measure.

This paper describes the rotational behavior of the vehicle in the vertical plane at frontal collision against a flat barrier. The control of the rotational behavior is important because this often has a great influence on both passenger compartment integrity and occupant protection. The authors examine the cause of this rotational behavior of the vehicle using the numerical simulation of a full scale passenger car model with an explicit finite element method. As a result, it is found that the deformation process and the transmitted force of basic framework greatly affect to the rotational behavior. The simulation explains its difference between a typical FR (front engine &, front drive) vehicle and a FR (front engine & rear drive) vehicle. The mechanism during the rotational behavior is analyzed by means of the transmitted force to subsequent frame members. The typical comparison of the simulation and the vehicle test are also presented.