Study Of The Occupant Crash Protection Performance Of The Negative Poisson’s Ratio Seat Belt Webbing

Dependency on vehicle is rising in people’s lives with the vehicle holding is ever-increasing. Driving safety has been one of the three problems that need to be solved urgently for auto industry. The seat belt system is able to fix occupants on the seat avoiding secondary collision between occupants and automobile or hurts while be thrown out of the cab in a car-crash accident. As the traditional belt narrows in width while be stretched which leads to too much pressure and over-compression of occupants’chest and abdomen and harm to viscera, even threat to lives. A new-type belt characterized by negative Poisson’s ratio, as a result, is researched to improve protective effect, which is of great importance.The conception of negative Poisson’s ratio belt is proposed based on analysis of the research development of domestic and abroad negative Poisson’s ratio materials and structures. The deformation characteristics and advantages over the traditional belt for protecting occupants of negative Poisson’s ratio belt are verified and the influence on protective effect of negative Poisson’s ratio belt from the value of negative Poisson’s ratio and friction coefficient between belt and body are analyzed by FE simulation. The protective effect for occupants of negative Poisson’s ratio belt is verified with vehicle front impact simulation including a Hybrid III50th dummy model by MADMO.A belt webbing model characterized by auxetic effect and convex-concave surface is established according to previous studies. The deformation mechanism of auxetic unit and negative Poisson’s ratio belt webbing and influence on geometry from the structural parameters have been analyzed. Influence on equivalent Poisson’s ratio from the structural parameters is studied through tension FE simulation. The simulation model of protective effect for occupants of belt webbing characterized by negative Poisson’s ratio is established based on the explicit-dynamic analysis in ANSYS/LS-DYNA, in which influence on protective effect from the wearing way, amplitude A, power exponent m and periodical coefficient n are studied taking the contact force and compression as evaluation index. The researches results make contributions to apply on vehicle occupants restrict system of negative Poisson’s ratio material.