Advanced Curtain Airbag Modeling Using the Uniform Pressure Approach Combined With a Gas Flow Analysis 2004-01-1632
Curtain airbag simulations become more and more complex in order to get the best correlation between the numerical simulation and the (hardware) experiment possible. Detailed airbag folding and gas flow simulations already have been introduced as the solution to model the real deploying condition as close as possible. But these advanced methods do also have disadvantages like requiring extensive computing time and detailed input information (for example the gas mixture).
This paper presents a new methodology for curtain airbag modeling using the uniform pressure method combined with an analysis using the gas flow approach. It is taken into account that a curtain airbag is often inflated by gas distributed over the airbag by vent holes in the diffuser tube. To obtain the outflow characteristics (mass flow rates and temperatures) of each hole in the diffuser tube, new features of MADYMO R6.1 were used. After acquiring the mass flow rate and temperature through each vent hole using gas flow, these data were applied to a uniform pressure model of the folded airbag, resulting in a model with multiple inflators taking into account timing effects in the deployment phase.
In this paper the results of using this method for two different curtain airbag simulations will be described. The results are compared to experimental data. It can be concluded that even if there was an initiative weak point in the uniform pressure method related to curtain airbag simulations, this new method partly using gas flow could be an efficient and promising way to avoid the shortcomings of the uniform pressure method but still having the advantages as relatively small CPU costs and easy modeling.