Side Occupant Restraint System Design Integration And Optimization For Passenger Car

As a most crucial indictor of vehicle performance, vehicle passive safety hasbeen attracting more and more attention by consumers nowadays. In China, the sideimpact incident happens very often as a result of the multiple intersections and thevarious types of vehicles on highway. In recent years, the fatality of side impact hasbecome second to only front impact, causing great casualties and loss of properties.Thus, the research on vehicle side impact safety has demonstrated significanteconomical and social importance.Due to limit on space and energy absorption of the side structures, the siderestraint system has a great influence on improving crashworthiness of the vehiclewhile reducing dummy injury. Moreover, the worldwide impact regulations aregradually taking pole test and dummy devices with higher bio-fidelity into actual testprocedures, seeking for stricter requirements on occupant thorax and head protection.This tendency would result in a wide spread of in-vehicle thorax airbags and curtainairbags usage and researches on their optimal coupling with the vehicle. Therefore,it’s meaningful and practical to investigate on the design, integration andoptimization of side restraint system.This paper is conducted based on a middle class passenger car and the structuredesigning phase has been accomplished. A corresponding side restraint system isdesigned, integrated and coupled based on a finite element model of this car. Thefinal goal is to achieve three stars score in the C-NCAP side impact test.Ls-dyna software is used to establish the whole-vehicle based side impact model,and dynamic characteristics are outputted to set up baseline. According to thecharacteristics of side structures, initial restraint system design is established. Themodulated design consists of inflations of thorax and curtain airbag, selection of folding type, and analysis of the fabric surface pressure.This paper has established a virtual sled model for a quick integration of siderestraint system and parameter optimization. Based on finite element and multi-bodycoupling method, occupant sub-system, restraint system and vehicle structure areintegrated together to calculate dummy injury. Aimed at reducing injury, parameterssuch as the ignition time, inflation curve and vent size are optimized for the bestoutcome. Finally, the dummy injury and efficiency of restraint system are validatedby virtual test on a whole-vehicle level.The research conducts modulation methods to develop corresponding siderestraint system for a passenger car. It has improved the protection of side occupantson a sled test base and whole-vehicle test base. And it is essential for enhancing theanalytical abilities in field of side restraint system research and masteringoptimization method for engineering purposes.