Research On Cyclist Injury And Helmet Protective Performance In Car-Bicycle Collision

The ‘green travel’ initiative is advancing with the times and in line with the needs of the development of the times.Under the background,more and more young people choose share bicycles as a way of short-distance travel.However,the resulting of high incidence about car-bicycle collisions has undoubtedly caused serious injuries to people and caused serious losses to society.People have paid more and more attention to this type of accidents.Because the current road traffic safety regulations are not perfect,the awareness of cyclists to comply with traffic laws is relatively weak,and the unreasonable traffic road planning in many places has caused motor vehicles and non-motor vehicles to be forced to mix,and when a traffic accident occurs,because of the characteristics of bicycle structure,it cannot provide effective protections for cyclists and passengers.These are the reasons that lead to the serious situation of automobile-bicycle traffic accidents in my country.Firstly,this article uses Hyperworks and LS-DYNA as the simulation platform,and uses vehicle speed and collision position as variables to simulate and analyze the THUMS human body model.Specifically,according to the NAIS(National Automobile Accident In-depth Investigation System)database and the CIDAS(China In-depth Accident Study)database,a statistical analysis of automobile-bicycle collision accidents is carried out,focusing on the distribution of collision locations and collision speeds,and design the test plan based on this variables.Create a three-dimensional model based on the data obtained from actual surveying and mapping,and generate a bicycle finite element model after Hyperworks pre-processing,and set up contact connection with the car finite element model and the THUMS human body model after adjusting the posture to study the injury of pedestrians under different working conditions.Secondly,use Proe software to establish a three-dimensional helmet model,take pre-processing in Hyperworks software,and then establish a helmet-mounted car-bicycle-cyclist collision simulation model,study the differences in head injury of the rider before and after wearing the helmet,and analyze the protective effect of helmet on the head.The simulation test results show that there is a significant correlation between the injury degree of the bicycle cyclist and the speed of the car.As the speed increases,the evaluation index reflecting the human injury increases significantly.From the evaluation index of the head,it can be seen that the riders’ heads are more likely to be injured in collisions.From the chest evaluation index,it can be seen that the collision position has a greater impact on the degree of chest injury.From the lower limb evaluation index,it can be seen that the lower limb is more likely to fracture in a collision accident.Therefore,it is necessary to take effective measures to protect the lower limbs.After wearing the helmet,the intracranial pressure and the equivalent stress of the skull of the bicycle cyclist are significantly reduced,but the plastic strain of the head skin will still increase with the speed of the car,it can be seen that the helmet has insufficient protection against plastic strain of the head skin.This paper conducts an in-depth study on the damage characteristics of vulnerable road users in my country in collision accidents,and provides a data reference for the research on the protection of cyclists in car-bicycle collision accidents.