Hello Everyone,
I want to perform a slow speed crush simulation using explicit solver in Ls dyna, the impactor crushed the target which is held constrained by a rigid wall. As per my understanding, since the impactor has a huge displacement, I shouldn't be including this in the *DAMPING PART MASS. But as I want the impactor to come into contact with the target at t=24 ms, so at that instant should I cncrease the load curve value to 1.0 and then decrease it again? or should I increase the value at the start of the simulation (as shown in the picture, where red point indicates the moment when the impactor comes into contact)?
VG
Hi @kein_roboter,
Here's a good overview of damping:
https://www.dynasupport.com/howtos/general/damping
My suggestion is to first run your simulation without damping, so you can have a baseline to cross-check your results with damping. Damping is optional but if you decide to add it to your simulation, you might need to do some adjusting. Your target should be 10% critical damping.
Are you using boundary prescribed motion for your rigid walls? And what is the total displacement? If you simulation is a slow controlled crush of a vehicle, then these rigid parts will be undergoing rigid body motion the entire simulation, so your curve idea won't work. It would work if it were something like *Initial_velocity. I think the most simple implementation would be to use *Damping_global and just see what you get. Then you can try *Damping_part_mass_set and add all parts except your rigid walls.