Gas Dynamic Simulation for Curtain Airbag Deployment through Interior Trims

The curtain airbag is usually simulated by a uniform pressure method in which the pressure of the airbag is considered as constant. This is correct when the airbag is fully deployed. However, this assumption is not valid during the curtain airbag deployment phase, where the gas flow passing through each chamber can be clearly seen. Therefore it is impossible to simulate the intermediate sequences of the airbag deployment correctly by using the conventional uniform pressure method. ® The gas dynamic module has been made available within LS-DYNA . This module provides the basic toolset to simulate gas flow. This technique enables us to simulate the gas flow and pressure distributions in detail and enables the correct sequences of the curtain airbag deployment. Interactions between the airbag and interior trims can now be simulated and well understood. This gas dynamic simulation method can be implemented to identify the potential failure modes of the curtain airbag during deployment through trims in the design development stage of the programme. Therefore, the confidence level for “right first time” curtain airbag deployment can be greatly increased.