A Study On The Intelligent Restraint Systems Of Drivers In Vehicle Frontal Impacts Using Mathematical Models

At present, the Hybridâ…¢50^th percentile test dummy is required in the regulations of frontal crash test and vehicle evaluation system in China. The Hybridâ…¢50^th percentile test dummy is mainly used to measure the biomechanical response of body in the front crash. However, with the dramatic increase in car ownership, the numbers of drivers are growing, especially women drivers have occupied a large proportion. Therefore, the car in the design process only taking the Hybridâ…¢50^th percentile occupant into account could well protect the female occupant of small stature during the collision will become a question.The purpose of this paper is to discuss that a smart restraint system protection is needed for occupants of different statures by comparing the dynamic response of the Hybridâ…¢50^th percentile dummy, Hybridâ…¢5^th percentile dummy and Hybridâ…¢95^th percentile dummy in a similar collision conditions.In this paper, the finite element method and multi-body method were used to built the simulation model of Hybridâ…¢50^th percentile dummy in the frontal impact. And this model was validated by real vehicle test results. On this basis, established the simulation systems of Hybridâ…¢5^th percentile dummy and Hybridâ…¢95^th percentile dummy in the front impact. The parameters of these two systems were consistent with parameters of the model of Hybridâ…¢50^th percentile dummy. By comparing the kinematics and dynamics response of the three dummies in these three cases, analyzed the injury risk of different occupant bodies in frontal impact. And analyzed the feasiblility of reducing the injury risk of female occupant in the vehicle frontal crash by using intelligent restraint systems.Then carry out the optimization of the intelligent restraint systems. First, optimize the restraint system of the Hybridâ…¢50^th percentile dummy which was validated. In the process of optimization design, used orthogonal experimental design analysis to determine the main design parameters, and then established second-order response surface model of optimizing objective, used the model to solve the result. On this basis, selected the maximum mass flow rate of the airbag and the level of seat belt force limiters as design parameters to optimize the design restraint system of Hybridâ…¢5^th percentile dummy.The results show that: the restraint system witch can well protect the Hybridâ…¢50^th percentile occupant restraint system can not properly protect the Hybridâ…¢5^th percentile occupant. Hybridâ…¢5^th percentile occupant has a greater risk of neck injury than Hybridâ…¢50^th percentile occupant in the similar constraints, can reduce this risk by adjusting the mass flow rate of airbag and seat belt force limiters limit force level, to provide more comprehensive protection for the occupants.After optimization of intelligent restraint systems, can got WIC of the model include Hybridâ…¢50^th percentile dummy obtain the minimum value of 0.469 in the design point, compared with the initial design point value of 0.650 was reduced about 30%.â… of the model include Hybridâ…¢5^th percentile dummy obtain the minimum value of 0.3625 in the design point, compared with the initial design point value of 0.5106 was reduced 29%.The results of this study have some reference value for the study of injury protection of different bodies in frontal collision.