A Study Of Rear Occupant Injury Protection From Car Side Impact

The usage of the rear seat is very widespread in China. It indicates that theinjuries and deaths of the rear occupant occupy a certain proportion in the number ofmore than30million people due to injuries and deaths every year in our country. Thefacts have proved that, the rear occupant, especially the short stature of women andyouth were likely to suffer more serious injuries in the real road traffic accidents.China will begin to implement the latest version of the Chinese New Car AssessmentProcedure (C-NCAP), and rear occupant injury will be included in the scoringcriteria since July1,2012.The aim of the present thesis is to study the injuries of the rear occupant by theinjury indicators that prescribed by the standard of C-NCAP (2012). Comparison andanalysis of the differences of occupant injury before and after the model adding therestraint system, and present some countermeasures to protect the passengers anddiscuss their validity in Computer simulation analysis.Firstly, the paper summarizes the traffic accidents type and the developmentoutline of automobile passive safety in recently years. In addition, the papercompares the different collision regulations and standards of side impact at homeand abroad. In the base of the theory of the finite element analysis, the FE model ofvehicle and MDB are all established and validated by comparing the simulationresults and test results according to C-NCAP. A PSM sub-structure including sidebody, dummy and rear seat was established combined with MADYMO, whichcontacted the motion of the finite element model with the dynamic response of thedummy, getting the injuries of the dummy and analyzing the injuries according to theinjury index under the standard requirements. After the injury results were analyzedand discussed under the different impact angle and position impact conditions. Inorder to improve the rear occupant, the paper discussed the occupant injuries in thesituation adding the occupant restraint system. The paper established the finiteelement model including the interior, seat belts, side airbags and side-curtain airbags,analyzing the influence in head protection of the rear passenger. At the same timecontrast investigated the changes of the chest and pelvis injuries index of the dummyunder the different conditions.The results of this study indicate that the head of the rear occupant was likely to suffer more serious injury than other parts, and the head injury index (HIC) was toolarge. However, the resultant force of the pelvis was much smaller than the standardvalue pre-established. After adding the restraint system to protect the head of theoccupant, it showed that the usage of the interior trim, belts, side airbags and sidecurtain airbags could effectively reduce the HIC value of the head of occupant. Theinterior trim could reduce the value of HIC by30.92%，the usage of seat belts couldbe further reduced by39.26%, and finally the usage of the side airbags or the sidecurtain airbags could reduced by99%and96.9%, and ultimately the value of theHIC was reduced23.213and87.634respectively. It proved that the side airbags andthe curtain could effectively protect the head of the occupant, and the use of therestraint systems not lead to adverse influence to the chest and pelvis of the occupant,and the index value also within the limits. The simulation results showed theirpositive effects and that they were strictly helpful on studying the rear occupant inside impact in the future.