Study On Pedestrian Motion Morphology And Damage After Emergency Attitude Collision

Pedestrians are extremely vulnerable in traffic accidents,the relevant data indicated that the pedestrian mortality rate in China is as high as 25%.According to the statistical data,it is found that the collision of pedestrians and vehicles in the emergency posture before the collision is about 62%.Therefore,the damage and motion patterns of different emergency postures are studied,and the vehicle active and passive safety research based on the actual accident reconstruction and pedestrian protection has important practical significance.Firstly,according to the statistics of accident vehicle types in the NAIS system,the vehicle types in this paper is determined as are SUV,sedan and MPV,and three kinds of vehicle types are established according to relevant parameters.The scale of the50th percentile pedestrians in China is 169cm and the body mass is 50.5.Pedestrian models of 4 types of body types such as 65.5,75.5 and 80.5kg;and the pedestrian and vehicle frontal collision model was established and verified in the MADYMO simulation analysis environment.Secondly,using the single factor test method,the values of four influencing factors such as collision speed,vehicle type,body type and braking deceleration arevaried in the collision model,and simulation experiments are carried out to study the movement pattern of pedestrians after collision.The results show that the collision speed determines the pedestrian's throwing motion pattern;the model,body type and braking deceleration have no significant effect on the pedestrian's throwing motion pattern;under the same collision speed and model,the running avoidance attitude has the smallest throwing distance;under the same body type,The running avoidance posture pedestrians has the lowest throwing high;under the same braking deceleration,the forward leaning posture has the largest throwing distance,and the lower jaw posture has the smallest throwing distance.Thirdly,the damage factors of the collision speed,vehicle type,body type and braking deceleration are analyzed.The results show that when the collision speed is less than 90km/h,the head injury caused by the collision between the pedestrian and the vehicle in the standing posture is the most serious.The head injury caused by the collision between the pedestrian and the vehicle in the forward tilt posture is the lightest;when the collision speed is greater than 50km/h,the forward tilt Pedestrians have the most serious chest injury,followed by the standing posture,and the running avoidance posture is the lightest in the chest;the standing posture and the SUV,the sedan and the MPV collide at medium and high speeds,and the head,chest and calf damage are the most serious.Pedestrian posture Pedestrian leg injury is relatively small;the more obese body type,the more serious the chest injury of standing and running avoidance posture,and the lower the chest injury of the pedestrian squat posture;the same braking deceleration,the standing posture pedestrians have the most serious head injury,the running avoidance posture pedestrians have the lightest head and chest damage.Finally,based on the above research results,the appropriate factor level table is selected for orthogonal experiment design,and using the range analysis method,the pedestrian HIC value is used as the evaluation index,and the comprehensive impact of collision speed,vehicle type,human body type and braking deceleration on pedestrian damage is discussed.The results show that when the lean forward type pedestrian and the SUV speed is 30km/h,and the maximum braking deceleration of the SUV is 6m/s~2,the pedestrian has the least head injury;the lower jaw and the standing posture when the obese body and the sedan speed is 50km/h,in which the maximum braking deceleration of the sedan is 5m/s~2,the pedestrian has the least head injury;the running avoidance is under the lean body type and the sedan speed is50km/h.Among them,the maximum braking deceleration of the car is 6m/s~2.When the collision occurs under the test conditions,the pedestrian has the least head damage.