Abstract: Three folding pattern airbag model are developed, which are leporello-fold(L-fold), spiral-fold(S-fold) and petri- fold(P-fold). Based on three sets of virtual testing configurat-ions that are airbag test, impactor test and steering wheel test, the dynamics of the airbag and the relevant contacted components are analyzed. The results show that there are two clear periods during the airbag deployment; they are initial deployment that goes from 0～20 ms and inflated working process that goes from 20～100 ms. In addition, more folding layers and more interferer between each layer, more difficultly the airbag deploys, and such airbag will cause high pressure in the first period and maintain a low pressure in the second period. It is suggested that the P-fold airbag would cause less injury to the out of position occupants, and provide a good protection for the large occupants.

Key words: Airbag, Airbag deployment, Airbag fold, Computer simulation