The Injury Response And Prediction Of The Head Wearing The Helmet Under Different Impact Conditions

In the world,there are a large number of motorcycle and other two wheels.Under the increasingly complicated traffic situation,traffic accidents occurred frequently.The drivers of the two-wheel vehicles represented by the motorcycle were faced with a greater risk of accident casualties,and the head injury was one of the main cause of death and serious injury of the drivers of such kind of vehicle.Wearing a helmet could prevent or reduce the damage to the head.However,the current helmet standard did not cover all the real collision conditions,which caused that the current helmet could not fully protect all types of head injuries,and head injuries were still frequent.In addition,the evaluation criterion of the helmet standard is limited to the dimension of head kinematics and has not been included in the more accurate dimension of head biomechanics,thus,it is difficult to assess the helmet protection capability completely.Aiming at the problems existing in the above-mentioned helmet protection,this paper establishes a highly accurate helmet-head coupling model by combining experimental and numerical methods,and carries out a series of research on the structural response and head response of the helmet under different crash conditions.The forecasting model of head response was innovatively put forward,and some new insights were obtained on impact response of helmet under different conditions,which can provide new guidance for future design of protective helmet.The main work is as follows:(1)Establishment and experimental verification of finite element model of helmet.The finite element model of AGV-K3 motorcycle helmet was obtained by blue light three-dimensional scanning,reverse engineering and finite element model modeling.To verify the accuracy of helmet model,according to CE R22 05 standard,two helmets were used to conduct drop tests on flat anvil and curb stone anvil at points B and R respectively.Then,the Hybrid III rigid head and the THUMS biomechanical head were coupled with the helmet model to simulate the drop test.According to compare the results of experiment and simulation,the accuracy of helmet model was verified.(2)Analysis of head kinematics and biomechanical response under different impact conditions.First of all,considering that the helmet impact protection mechanism was still unclear,the structure response and head response of the helmet were analyzed based on the results of the drop test.Secondly,in order to solve the problem that standard conditions fail to reflect the real accident conditions,based on accident investigation data and standard contents,head injury response under different boundary input conditions was explored by setting reasonable simulation matrix and established a new impact location uniform distribution method.(3)Prediction of head injury response under impact.Firstly,based on the method of correlation analysis,the relationship between the two kinds of response of head impact under helmet protection was studied,and the peak prediction model between kinematic parameter and biomechanical parameter was established;The prediction model was verified under additional impact conditions,and the prediction accuracy of the model was verified.Further,in order to realize the complete quantitative prediction of damage response,the result data of two kinds of evaluation indexes were trained by BP neural network learning algorithm.