Analysis Of Occupant Head Injury And Development Of Head Injury Component Test Device Under Horizontal Impact

The head injury of occupant is a key indicator for aircraft seats certification and installation.At present,the full-scale sled tests are used to show compliance for head injury,which are poor in economics and low in repeatability.This article studied the head injury of occupants under horizontal impact,and developed a head injury component test device,which could partially replace the full-scale sled test and provide technical support for airworthiness certification and installation of aircraft seats.Firstly,based on the requirements of airworthiness regulation 25.562,the full-scale sled test was conducted,and the corresponding numerical analysis model was established to study the dynamic response of the head of the occupant.The full-scale sled test model of "FAA Hybrid III Dummy –seat and restraint system-sled " was simplified into a simplified model of "pendulum mechanism-actuating device".The simplified model was validated to have similar head injuries with full-scale sled test model.Secondly,based on the validated simplified model,the motion mechanisms and different parts were designed and assemblied and then the kinematics analysis were conducted for head injury component test device,which laied the foundation for the manufacture of head injury component test device and the selection of power system.The hydraulic servo system,which were the power of head injury component test device,were designed,tested and validated.Aiming at the electrical control system,the main components were selected and the electrical circuit was designed.The PLC was used to control the movement of the device,and a data processing method of the head velocity and the head angle was established.The head injury component test device was developed.Finally,the numerical model of the head injury component test device was used to conduct the impact simulation of the head-up display and airbag.The orthogonal experimental design of the fiber fabric stiffness and exhaust coefficient in the airbag model was performed.The results indicate that under the emergency landing the injury risks of head and neck which were caused by head-up display were low.The airbag had good protection effect on the head of the occupant,but the use of the airbag caused the head to rebound after impact,causing damage to the neck.The head injury and neck injury had negative correlations with exhaust coefficient and positive correlations with airbag height.The negative angle of the airbag could better protect the head and neck of the occupant.