Meshing and Folding

The airbag fabric should be meshed in the non-folded state using tria elements with an average element size of 3 to 4mm. Larger element sizes are only acceptable for vent holes and other components that use a void material (example, inter-chamber void component). All nodes of void related elements should be attached to the surrounding fabric components. Airbag fabrics have a low modulus of elasticity and therefore normally the elements size does not affect time step.

External airbag fabric components should form a closed volume with normal vectors directed outwards. Intersections between any airbag components (e.g. external, internal, inflator, or housing) are not allowed.

Airbag folding should be performed using pre-simulation according to the CAD folding design. The folding model should use validated fabric material definitions and contacts. Radioss is the preferred solver for pre-simulation folding. This guaranties that the folded model will work correctly with the airbag internal contact definition listed in corresponding sections.