Research On The Effect Of Pedestrian Emergency Posture On Self-injury In Pedestrian And Van Accident

The article briefly introduces the in-depth investigation method of traffic accidents in the national vehicle accident in-depth investigation system,and makes statistics on the collected accident data.It is found that the proportion of vans in the accident models is second only to cars,and the vans are mainly vans.There are very few active safety configurations for cars,which are more likely to cause pedestrian injuries than cars.Therefore,this article only selects vans as the research object;at the same time,pedestrians often take emergency posture when facing danger.According to the statistical results of the data,four single emergency postures and angle change directions of pedestrians are defined,and two single or two emergency postures are combined into six new composite emergency postures.The multi-rigid body software MADYMO was used to reconstruct the collision model of pedestrian and vehicle accidents,reproduce the pedestrian dynamic response process,and verify the accuracy and feasibility of the model.To study the effect of pedestrians' different speeds on pedestrian injuries under different emergency postures.The results show that: among the four single emergency postures,there is a big difference in pedestrian head injury laws;pedestrian chest 3ms acceleration tends to increase in forward posture,squat posture,and stride posture,of which the maximum increase in forward posture is 40 km / At h,the increase is 79%;the emergency posture of the upper body movement changes such as leaning forward,the steering has little effect on the lower leg,the squatting posture is beneficial to protect the left calf,and the stride posture is beneficial to protecting the right calf.Pedestrian single emergency posture compared with normal standing posture,emergency response is beneficial to protect the head,chest,and left calf,and will aggravate the injury of the right calf except the forward leaning posture.With the change of different angles,the average HIC value of the head and chest 3ms acceleration in the single stride posture are the smallest,73.5% and 29.6% less than the normal standing posture respectively;the minimum acceleration of the left calf in the single forward posture is 46.7% less than the normal standing posture.In the six composite emergency postures,the damage situation is summarized as follows:the steering + forward tilt posture is more head injury than the single steering posture,the left calf injury is lower,and the chest injury is greater than the single forward posture;the steering+ squat posture is greater than the single squat posture Pedestrian pedestrian head and chest injury is greater,the average pedestrian HIC squatting at 30° turning is 57.7% higher than that of single squatting posture;steering + striding posture is higher than head and chest of single turning and striding posture High injury;stride + forward lean posture lower calf injury than single forward lean posture and higher head injury than single step forward;stride + squatposture higher head and chest injuries than single squat posture;forward lean + The squat posture has more head damage than a single squat posture.At a collision speed of 40km/h,the pedestrian's injuries for pedestrians with different walking speeds are summarized as follows: In general,the faster the pedestrian's walking speed,the greater the pedestrian's head,chest,and left calf injuries,and the lower calf injury is reduced;In a single stride posture,with the increase of the stride angle,the pedestrian's head injury gradually increases.When the pedestrian speed is 7.5km/h,the head HIC value growth rate is 35%,and the chest 3ms acceleration also follows the stride The step angle increases and increases but does not exceed the threshold of 60 g.