Study On The Calibration Strategy Of Airbag Based On The THUMS Model In Low-speed Impact

The casualty rate of occupants during the traffic accident has reduced since the airbags were widely used.However,the airbags are mostly imported from foreign countries,and the calibration strategy is formulated according to foreign traffic accidents and regulations,which is not adapt to the specific condition of China.When the imported airbags are used,it may result that,occupants' safety will be threatened in some accidents.Therefore,it is necessary to analyze and verify the calibration strategy and put forward the optimization suggestions according to the situation of China.This paper focuses on the calibration strategy of airbags in low-speed impact,and establishes the Hybrid dummy III and THUMS human model based on a domestic B-class car by using finite element analysis software HyperWorks and LS-DYNA.Through the comparison of the injury of the Hybrid III dummy vehicle model and the THUMS human model in the same condition,firstly,it verified the accuracy of the finite element model,besides,it proved that the THUMS model can assess and predict the occupants' injury more accurately and read the impact process of the human brain,bones and internal organs' injuries directly and accurately.According to the existing airbag calibration matrix,this paper built two 23km/h frontal impact restraint system models of A-class and B-class vehicle,and got the conclusion that the airbags of B-class vehicle should not deploy,while the A-class vehicle's should deploy,By comparing the injuries of THUMS model's head and chest under the condition of 23km/h frontal impact.In order to explore the reasonable airbag calibration matrix further,this paper set up the simulations of A-class and B-class vehicles at different collision speeds and airbag deploy times,and analyzed the injuries of THUMS model under different conditions.The conclusion is that,it has a better protection to driver when the A-class vehicle's airbag deployed at the speed of 23km/h frontal impact and the best deploy time of airbag is about 40 ms after the impact,while the B-class vehicle is 30km/h and 35 ms.The research results show that the existing airbag calibration strategy cannot be applied in all vehicles.Doing further research based on the specific vehicles,can not only effectively reduce the airbag misuse accidents,improve the safety of vehicle low-speed impact,but also can be conducive to build China's airbag standards and improve relevant laws and regulations.