about the UniaxialStrainer

Asked by xjin on 2019-07-20

I try to use ‘UniaxialStrainer’ to complete a simulation of uniaxial compression test for a cylinder rock specimen.

The engines is below,
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O.engines=[
……,
UniaxialStrainer(strainRate=strainRate,axis=axis,asymmetry=0,posIds=posIds,negIds=negIds,crossSectionArea=crossSectionArea,blockDisplacements=False,blockRotations=False,setSpeeds=setSpeeds,label='strainer'),
#
……,
]
---------------------------------------------------------------------
1.Dose this mean
'the particles in the posIds and negIds are only set to have one degree of freedom-normal straining in the axial direction.'?

2. it also means ' the particles in posIds and negIds move towards the centre of the rock specimen at same velocity during the loading process.'?

3.Dose 'the particles in posIds and negIds ' means the particles to be part of the top plate and bottom plate? and should I set the blockedDOFs of the 'the particles in posIds and negIds ?

Thanks very much!

Question information

Language:
English Edit question
Status:
Solved
For:
Yade Edit question
Assignee:
No assignee Edit question
Solved by:
Jan Stránský
Solved:
2019-08-08
Last query:
2019-08-08
Last reply:
2019-07-21
Best Jan Stránský (honzik) said : #1

Hello,

1)
> blockDisplacements=False,blockRotations=False
Depends on what you meant, but according to what you wrote, it is completely opposite.
All DOFs are free and only the axial DOF is fixed/blocked/prescribed.

2)
> asymmetry=0
yes

3)
> ... part of the top plate and bottom plate?

I prefer "layer" instead of "plate", but yes

> should I set the blockedDOFs of the 'the particles in posIds and negIds ?

see 1), the blockedDOFs are controlled by blockDisplacements and/or blockRotations.
You should not set blockedDOFs directly, but it is possible.

cheers
Jan

xjin (jpeng22) said : #2

Thanks Jan Stránský, that solved my question.