Airbag Simulation using LS-DYNA: start from filled airbag

[ArianaFenris]

TL;DR Summary

How do I start my LS-DYNA impact simulation from a filled airbag?

Hello! I'd like to model the impact of an object on an inflated air cushion (effectively an airbag) at rest in LS-DYNA, however all the tutorials I see start from a deflated airbag. I would like to skip this computation if possible to save computing time, since I would have to run the simulation until the bag stops oscillating.

Also, could I place the cushion on a solid surface so that the cushion's deformation is restricted from below?

Can I inflate the cushion to differing fill fractions other than a completely filled bag?

I'm not very familiar with LS-DYNA, any help is much appreciated. Thanks!

 

[berkeman]

I'm not familiar with the mechanical simulator LS-DYNA, but for the electrical circuit simulator SPICE (available in various vendor packages), you can set "Initial Conditions" with the .IC command line or though other mechanisms in the GUI interfaces. Does LS-DYNA have anything like that (look in the Help pages)?

Also, another strategy with SPICE is to run one simulation to get to the initial conditions, and save that state to use as the starting state for multiple subsequent simulations. Can you save a state at the end of filling up your airbag?

https://resources.pcb.cadence.com/b...itial-conditions-and-interpreting-the-results