Research And Simulation Of Human Body Protection By Safety Constraint In Car Driving Area

The security problem of car driving is a hot research area. When colliding, driving area safety constraint system is to reduce the occupant injury in a reliable way. On the basis of Occupant Restraint System Simulation Model, this paper raises the issue of occupant protection under different security constraints in driving area by combining with an instance of a car head-on collision, and makes deep analysis and research to provide a theoretical basis for the development of vehicle driving area security constraint system.This paper mainly focuses on the study of following aspects.1. This paper systematically expounds the human body biomechanical response and evaluation standard of each part of the human body injury, and by combining L-E in Multi-rigid-body system dynamics theory with Collision theory, we deduce Human Kinetics Model in colliding. We determine the limit value of each part injury based on occupant injury biomechanics.2. We use MADYMO to build simulation models containing driving area, dummy, car seat belts, airbags and so on; modify the model according to the basic principles of engineering modification; prove the validity of the model by comparing their head, chest and hip acceleration from test data.3. Based on simulation models, we analyze the influences of human posture on occupant injury respectively from seat belt stiffness, crew sitting position and car seat cushion, and calculate the mechanics physical quantity and damage output value of the head, chest and hip. According to obtained data we conclude:(1) Within a certain range, the greater of the belt stiffness, the worse of protection on the chest and pelvis, but it does not exhibit obvious regularity to the head.(2) When the body’s forward tilt angle is between-10 and 10 degree with sitting position changed, head acceleration and HIC value are inversely proportional to the angle, chest is proportional to the angle, but there were no significant changes to pelvis acceleration. When the forward tilt angle is too large, acceleration reaches its peak time earlier, which means when the airbag is not fully bounced, the head has already contacted to the airbag. As a result, the head injury is aggravated.(3) When the cushion inclination angle increases from 0 to 30 degree, the head HIC value decreases by 38.78%, and the chest 3ms value decreases by 17.07%. On the other hand, the leg acceleration index increases by 9.25% only with cushion inclination angle increasing from 10 to 30 degree in collision. However, when the angle is 0 degree, the body’s acceleration value becomes very large. It indicates that the appropriate cushion inclination can reduce damage to the human body.