Checklist
Useful checklist for airbag modeling:
- All airbag fabric components are meshed with tria elements according to meshing requirements (3-4mm average size)
- Airbag is free from intersections
- If the airbag will be used in a larger simulation, the entity ID numbering is correct based on requirements of the larger model
- The airbag model is divided into /SUBSET representing the airbag external surfaces, vents, internal surfaces, housing, and inflator
- Mass and inertia of the model matches the physical part
- Fabric material data was validated using biaxial, picture frame and uniaxial tests
- Vent holes are modeled
- Porous fabric is modeled
- Gas material for each gas component is modeled
- Inflator is validated using a tank test simulation and comparing the mass flow and temperature curves to the tank test results
- Gas injections starts at TTF defined in /SENSOR Tdelay not by offsetting massflow and temperature curves
- The mass flow curve start with non-zero values
- function is increasing monotonically for each gas
- Reference geometry is present either as nodal based /XREF or element based /EREF
- The same /SENSOR is used to activate injection and activate reference geometry in LAW58
- Ambientand internal air material properties are specified
- Either the /FVMBAG1 or /FVMBAG2 card is specified
- Internal airbag contacts defined and HyperCrash penetration check shows no intersections and a maximum penetration amount of 10% of the contact gap
- Stability run is done to check for motion before TTF
- Uniform pressure run is completed, no anchoring of contact nodes
- Stand-alone FVM run is completed, no anchoring of contact nodes and realistic unfolding
- Model runs with required time step
- Number of FV does not reduce to one
- Visual development of the flow (temperature contour plot, fluid velocity vector) is realistic