Tiny particles don't react with the wall
Hi,
I have a sand model with extral tiny particles among the pore space of the sample, and I use this model for triaxial compression test. The boundary condition is simulated by six rigid walls (use walls=aabbWalls
However, I found that at the end of the simulation (where axial strain = 40%), many tiny particles stay at their original places, which means that these tiny particles didn't react with the boundary wall during the simulation, the example figure could be find at [1].
I guessed it is that there was no contact detection between these tiny particles and the top wall so that these particles passed through the top wall. Then I set the timestepSafetyC
My questions are: (1) The higher the timestepSafetyC
Thanks very much!
Leonard
[1]https:/
Question information
- Language:
- English Edit question
- Status:
- Solved
- For:
- Yade Edit question
- Assignee:
- No assignee Edit question
- Solved by:
- Jan Stránský
- Solved:
- 2021-01-01
- Last query:
- 2021-01-01
- Last reply:
- 2020-12-26
|
#1 |
Hello,
> I use this model for triaxial compression test
> the example figure could be find at [1]
please provide the code [2]
> I guessed it is that there was no contact detection between these tiny particles and the top wall so that these particles passed through the top wall.
it is the most reasonable explanation
> And I use GlobalStiffness
> Then I set the timestepSafetyC
GlobalStiffness
> (1) The higher the timestepSafetyC
GlobalStiffness
So the lower value, the more safety.
But again, safety w.r.t. stiffness, not particle sizes/velocities. So for this problem, go another way than timestepSafetyC
> (2) Is there any other way to let the missed contacts being detected correctly during the simulation?
of course. For example you can:
- set maximum wall velocity
- compute respective time step such that the maximum wall displacement during one time step is some fraction of tiny particles size
- set this time step as maxDt [4].
cheers
Jan
[2] https:/
[3] https:/
[4] https:/
Leonard (z2521899293) said : | #2 |
Hi Jan,
Thanks for your reply.
Besides the way you suggest, I also tried using O.dt=(small value)*
Cheers
Leonard
[5]https:/
Leonard (z2521899293) said : | #3 |
Thanks Jan Stránský, that solved my question.