固定排气口型气囊冲击减缓特性研究

Study on Cushioning Characteristics of the Airbag with Constant Venting Area

为研究固定排气口型缓冲气囊冲击减缓特性,基于能量守恒及热力学方程建立了固定排气口型气囊缓冲过程的解析模型,并采用LS-DYNA和实验对其有效性进行了验证。基于该模型研究了竖直圆柱式气囊的缓冲特性,开展了初始压力、排气口面积和排气口触发条件对竖直圆柱式气囊缓冲性能的影响研究,并定义了初始极限压力。研究表明:当初始压力小于初始极限压力时,适当增大竖直圆柱式气囊的初始压力、选取合适的排气口触发条件,均可将设备的峰值过载维持在一个合理水平的基础上,减小气囊的体积;采用合理的排气口设计参数,可以提高系统的吸能率,降低峰值过载,同时避免设备的反弹。

In the study of the cushioning characteristics of the airbag with constant venting area,based on the energy conservation principle and thermal dynamics equations,an analytical model of the airbag with constant venting area is proposed and validated by LS-DYNA and experiments.Then,the cushioning characteristics of the vertical cylindrical airbag with constant venting area are investigated with this model.A series of calculations are conducted to find out the influence of initial inflation pressure,vent area and the triggering condition of the venting orifice on cushioning properties.The initial limit pressure is defined.Numerical results show that the initial inflation pressure and triggering condition of the venting orifice are key parameters which affect the cushioning properties.When the initial inflation pressure is less than the initial limit pressure,the appropriate increase of initial inflation pressure and appropriate triggering condition reduce the volume of the airbag and maintain peak overload of the equipment at a reasonable level.The reasonable venting area can improve the energy absorbing ratio,reduce the peak overload and prevent the airbag rebound.