rigid body simulation

rea2

I am trying to perform a simulation on rigid bodies in hypermesh using radioss as a solver, but the solver shows a very high nodal time step and does not compute the solution. 

Is there a way to assign the nodal time step in hypermesh beforehand? 

Pranav Hari

Hi rea2

 

You can use /DT/NODA/CST which add mass on the node when time step drops 

 

Refer the e-book (page 261 onwards) for more details regarding time step control

https://altairuniversity.com/free-ebooks-2/free-ebook-crash-analysis-with-radioss-a-study-guide/

rea2

thanks for the reply pranav,

but i would like to restate my question once again, I have only rigid bodies in my simulation and i am applying some forces on it ....but i am getting very high nodal time step and the simulation does not run for the specified time of 15 ms. I have 4-5 rigid bodies with possible penetrations and no contact defined between each other.

regards,

 

 

 

prat

hi pranav and rea2

is it possible to have only the rigid bodies in your simulation run in radioss? Won't it create a very high nodal time step due to the infinite stiffness of the rigid body?

And if that is the case is there a way to overcome this?

Simon Križnik

@rea2

 

If a model has only rigid bodies then Radioss will terminate on first cycle. Include a deformable element in your model (it will control the timestep) as a workaround.

 

@prat

 

Rigid bodies generally have timestep much higher than other finite elements so it is computationally efficient way to simulate components with negligible deformations.