Research On Head Injury Of Two Wheel Electric Vehicle Drivers Based On Fluid-solid Coupling Model

In the vehicle and two-wheel electric vehicle accidents in China,traumatic brain injury is the main cause of driver death.While traumatic brain injury poses a great threat to people’s lives,it also brings great economic losses to the country’s social and economic development.Therefore,the establishment of a high-precision head finite element model is of great significance for the study of head biomechanical damage in collisions.After a lot of researches by the predecessors,it is believed that the cerebrospinal fluid is a fluid material and the cranial-cerebrospinal fluid-brain contact mode is fluid-solid coupling.In order to study a method that can more realistically simulate the fluid-solid coupling relationship between skull-cerebrospinal fluid-brain,a meshless method of smooth particle fluid dynamics(SPH)is proposed to simulate the fluid-solid coupling relationship in the model study,and compare it with the arbitrary Lagrange-Euler method(ALE)often used in the study of fluid-structure coupling.By designing the head replacement model drop experiment,and using the pressure value as the verification parameter,the numerical theory and simulation study of the smooth particle hydrodynamic method and the arbitrary Lagrangian-Euler method are carried out.Then,based on the original CT scan-based 3D model of the head of the research group,further fine modeling is carried out.Hypermesh is used to pre-process the model and the smooth particle fluid dynamics algorithm is used to analyze the contact relationship between the skull-CSF-brain,and the finite element model of fluid-structure coupling of head is established in accordance with human anatomy to study its biomechanical response.At the same time,the established head fluid-structure coupling finite element model is simulated and verified with reference to foreign classic cadaver experimental data,including Nahum’s intracranial pressure experiment,Trosseille’s intracranial dynamic response experiment and Yoganandan’s drop experiment.In order to study the head injury of electric two-wheelers,MADYMO software is used to reconstruct the real collision accident.When modeling the two-wheel electric vehicle driver,the head fluid-solid coupling finite element model is combined with the multi-rigid dummy body to form a finite element-multi-rigid coupled two-wheel electric vehicle driver to ensure the accuracy of accident recovery.A simple multi-rigid two-wheel vehicle model is established,and the combined finite element-multi-rigid body driver model and electric two-wheel vehicle model are combined to form a human-vehicle combination model.At the same time,a simple multi-rigid car model and a road model are established to further form a human-vehicle-road combined system model.Carry out collision simulation research on real accident information to verify the effectiveness of the model.In order to study the head injuries of two-wheel electric vehicle drivers,statistical analysis is carried out using specific accidents and simulation analysis is conducted on the main factors to study head injuries from the perspective of biomechanics.Using the accident data of two-wheel vehicles in Shandong Province obtained from the Harbin Institute of Technology-Tianhong Forensic Laboratory database,the main component analysis is conducted for 9 factors,and the main component analysis results are independent of each other and could fully reflect the characteristics of all factors for statistical analysis.According to the results of statistical analysis,collision simulation analysis is carried out to study the specific head injury from the perspective of biomechanics.According to the test results and simulation results of the ball head replacement model,the two methods of SPH and ALE are feasible when simulating fluid-structure coupling.However,the SPH method can avoid the negative volume problem caused by large deformation of the grid during simulation,and can greatly improve the calculation efficiency,so it has more advantages when studying fluid-structure coupling.The simulation verification results of the head fluid-solid coupling finite element model based on the SPH method show that the simulation results are in good agreement with the experimental results and have good biological fidelity.Therefore,the established fluid-structure coupling finite element model of the head can accurately study the biomechanical response of the head and can be used for the study of brain injury under shock.It can be known from the collision simulation research on the simulation of human-vehicle-road coupling system and real accident information.Comparing vehicle damage,simulation results and actual accident final position comparison and electric two-wheeled vehicle driver head injury can verify the effectiveness of the model,and provide a model basis for studying head injury from a biomechanical perspective.At the same time,the simulation analysis of the head finite element combined dummy is carried out to verify the superiority of analyzing the head injury during the collision from the biomechanical perspective.The simulation results of different factors on the head injury show that the analysis of parameters such as intracranial pressure and intracranial stress can better analyze the head injury from the perspective of biomechanics.It is also concluded that different car speeds and collision postures have a greater influence on intracranial pressure and intracranial stress.