Study On Occupant Damage Of Left Rear Passenger Car Under Offset Collision With Different Overlap Rates

Car frontal collisions not only cause serious damage to the car,but also the damage of the insiders and passengers is often very serious.When a car is about to have a frontal collision accident,the driver usually takes the steering and braking avoidance measures for the instinctive reaction.Therefore,in the actual frontal collision,the collision overlap ratio between the car and the obstacle is more diverse.According to the road traffic depth accident investigation and analysis,the collision overlap rate and the occupant injury relationship in the vehicle are released.In the overlap rate range of 25% to 45%,the occupant casualty rate is very high and very dense.In order to analyze the response of the car at different collision overlap rates,different collision speeds and the damage characteristics of the occupants after the collision,and the restraint system of different working conditions,the protection effectiveness of the dummy under the frontal collision of different overlapping rates.In this paper,the finite element pre-processing software Hypermesh is used to locate the finite element car model and finite element deformable barrier issued by the National Highway Traffic Safety Administration(NHTSA),and to locate and adjust the HybridIII50 th percentile dummy of the US LSTC.The posture makes the dummy fit better with the rear seats.The simulation model including only cars,barriers and dummy is called model 1,then a three-point seat belt is created for the dummy based on the model 1,and the model 2 is created for the dummy based on the model 2.On the basis of the model 3,a head air curtain is created for the dummy to obtain the model 4.For the model 1,the collision speeds of five collision speeds of 30km/h,40km/h,50km/h,60km/h,70km/h and 55%,30%,35%,40%,45% are overlapped.In the crash test,the influence of collision speed and collision overlap rate on the damage of the left occupant in the rear row was studied by the control variable method.Then,model 2,model 3,and model 4 are subjected to collision simulation experiments with different overlap rates at the same speed,and the protection performance of different restraint systems for the left rear dummy is analyzed under the frontal collision of different collision overlap rates.The results show:1.With the gradual decrease of collision overlap rate,the x-acceleration peak and y-acceleration peak of the left occupant's head gradually increase;the peak force of the occupant's neck is not fluctuated with the decrease of the overlap rate.However,the values are all high,and the peak of the occupant's chest acceleration decreases as the overlap rate increases.2.When the collision overlap rate is 45%,as the collision speed of the car increases,the peak value of the false head of the dummy gradually increases,and the time when the head of the dummy reaches the maximum combined acceleration decreases first and then increases;the neck of the dummy is stressed.The peak value decreases first and then increases with the increase of the collision speed;the peak value of the dummy's chest acceleration decreases first and then increases with the increase of the collision speed.3.Comparing the dummy's working conditions without any restraint,the safety belt can greatly reduce the damage of the head,neck and chest of the dummy,and the maximum amplitude is reached when the overlap rate is 35%,30%,25% respectively.61.96%,66.81% and 94.18%.4.The side airbag has a certain protective effect on the dummy's chest.The protection effect is most pronounced when the overlap ratio is 30%.However,there is almost no protection for the dummy's head and neck.The side air curtain has a certain protective effect on the neck of the dummy,and the maximum force of the neck of the dummy can be reduced by 24% compared with the simulation result of the model 3 at the overlap rate of 25%,and there is almost no protection for the dummy's chest.5.When the collision overlap ratio is 35%,40%,45%,the side air curtain does not have a protective effect on the dummy head,and when the collision overlap ratio is 25% or 30%,the side air curtain has a dummy head.The certain protection effect makes the peak acceleration of the dummy's head lower than the simulation result of the model 2 by 45.9% and 20% respectively.