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#1 2022-03-03 11:03:43

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

LIAISION_MAIL problem

Good morning.
I'm doing a non-linear static analysis of a rim / hub / bolt simulating preload and induced displacement of 10mm. I started to implement step by step starting first with the rim only (where I can correctly visualize displacements and deformations). The next step is to glue the hub to the rim using the LIAISON_MAIL function, unfortunately the latter gives me an error. I have seen the documentation and believe I am using it correctly. I define a 3D group (master) and a 2D group (slave) using GROUP_MA_ESCL AND GROUP_MA_MAIT respectively. I don't understand what I'm doing wrong. I have attached the .comm and .med file but as you can see the mesh is not very dense, unfortunately due to memory limitations I was forced to decrease the number of nodes and elements. Thanks for your help


Attachments:
Mesh_1.zip, Size: 385.13 KiB, Downloads: 67

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#2 2022-03-03 11:49:24

jonas loenartz
Member
Registered: 2021-10-01
Posts: 51

Re: LIAISION_MAIL problem

Hello,

could you post the *mess-file as well? I ran your command-file with version 15.4 and didn't get an error for  LIAISON_MAIL, only an alarm for a distant node.

I also got alarms for duplicate elements and

La maille M86 porte un élément fini de bord, mais elle ne borde aucun élément ayant une "rigidité".

There also are some very questionable elements in your model, so I doubt it would run, even if you fixed the LIAISON_SOLIDE,
and there is only a single 3D-mesh zone for the hub. You definetely have to check your mesh.

Jonas

Last edited by jonas loenartz (2022-03-03 11:58:26)

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#3 2022-03-03 12:05:57

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

jonas loenartz wrote:

Hello,

could you post the *mess-file as well? I ran your command-file with version 15.4 and didn't get an error for  LIAISON_MAIL, only an alarm for a distant node.

I also got alarms for duplicate elements and

La maille M86 porte un élément fini de bord, mais elle ne borde aucun élément ayant une "rigidité".

There also are some very questionable elements in your model, so I doubt it would run, even if you fixed the LIAISON_SOLIDE,
and there is only a single 3D-mesh zone for the hub. You definetely have to check your mesh.

Jonas


Attachments:
stderr_command_salome.log, Size: 72.66 KiB, Downloads: 61

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#4 2022-03-03 12:12:23

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

jonas loenartz wrote:

Hello,

could you post the *mess-file as well? I ran your command-file with version 15.4 and didn't get an error for  LIAISON_MAIL, only an alarm for a distant node.

I also got alarms for duplicate elements and

La maille M86 porte un élément fini de bord, mais elle ne borde aucun élément ayant une "rigidité".

There also are some very questionable elements in your model, so I doubt it would run, even if you fixed the LIAISON_SOLIDE,
and there is only a single 3D-mesh zone for the hub. You definetely have to check your mesh.

Jonas

Hi, thanks for the reply. I'm not very familiar with code asters. I don't understand exactly what the problem is and what I should do now. I'm so sorry

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#5 2022-03-03 14:13:50

jonas loenartz
Member
Registered: 2021-10-01
Posts: 51

Re: LIAISION_MAIL problem

Ok, I see, you reduced the mesh size in order to post it in the forum. I misunderstood previously. I thought you meant your hardware-memory. Can you share the real mesh on some file-hoster and share a link perhaps?

LIAISON_SOLIDE is not necessarily the problem. You log-file says the matrix is not invertible, because the matrix is singular. This can happen, when your model is not fully constrained and you have rigid-body motion.

Do the GROUP_MA_ESCL and GROUP_MA_MAIT of your LIAISON_SOLIDE share any nodes perhaps?

Jonas

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#6 2022-03-03 14:41:52

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

@jonas
the mesh that i have downloaded does not contain a 3D group named CERCHIONE
is that a problem with window$ created mesh? i do not know
could you share the mesh you are using

anyhow this seems to illustrate the danger of using TOUT='OUI'  in some operator

i agree with you with you regarding the numerous bad element in the mesh 
without a proper mesh it is impossible to get an idea of what is going wrong

despite that the problem start but stop on the very first step with i guess a rigid body motion of MOZZO

one last thing to my opinion the mesh density is accurate enough to solve this type of problem

Last edited by jeanpierreaubry (2022-03-03 14:50:47)


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#7 2022-03-03 15:48:10

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

Thanks so much for the support. Thanks again Jean for your patience. The mesh that I have shared compared to the one I am using has a denser mesh (5mm) while the shared one of 10mm. I changed the TOUT = 'OUI' operator because it gave me a lot of problems before. I tried to run the calculation without the LIAISON_MAIL operator and the results of displacements and strees are unfortunately not what I am looking for. What do you advise me to do now? I think I apply liaison_mail correctly. Anyway I use Code Aster for windows, maybe for that Jean you can't see the CERCHIONE group. Thanks again.

Last edited by Giuseppe Faggiano (2022-03-03 15:48:54)


Attachments:
aster__.comm, Size: 6.2 KiB, Downloads: 60

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#8 2022-03-03 16:09:33

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

you are mixing important and non important problems

the troubles are probably not lying where you think they are

we are going nowhere if you use one given mesh for your calculation and share another one which obviously is not the same, i do not why, on this forum

mesh size is a non important problem at this stage

first
run the calculation with the mesh you share here to see how it goes

second
from the geometry make a mesh with mesh element size 10 mm, linear mesh no quadratic,
with ONLY GROUP_MA on the volumes and the surfaces
do NOT build any GROUP_NO i will explain why later
post it here


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freely available here https://framabook.org/beginning-with-code_aster/

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#9 2022-03-03 17:01:59

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

Hi Jean I'm listening to your advice. I tried to run the calculation with the shared mesh in this group (10mm), you are right the CIRCLE group does not exist and I don't explain how, the group is composed of 0 elements and 0 nodes but this does not happen only with the 10 mesh mm and not with the 5mm mesh I am using. As for the groups, I cannot create only GROUP_MA because for my model I also need groups of nodes to use the Boolean functions to eliminate common nodes and not have rounded conditions, since I use a local coordinate system because I have exploited the cylinder symmetry of the rim. I uploaded a link where you can view the mesh I am using. Let me know. Thank you

*https://drive.google.com/drive/folders/1BXT9I4ex5UTVCXX3W67bWhIAQKWWUmnm?usp=sharing*

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#10 2022-03-03 17:18:05

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

As for the groups, I cannot create only GROUP_MA because for my model I also need groups of nodes to use the Boolean functions to eliminate common nodes and not have rounded conditions

please do what i request

i will explain why later

Last edited by jeanpierreaubry (2022-03-03 17:18:47)


consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#11 2022-03-03 18:55:47

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

Hi Jean, if you reopen the link I shared you will find the changes you asked me for. A greeting

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#12 2022-03-04 08:23:58

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

this is not the coarser mesh i requested

i am trying to run your problem with the finer mesh
even without MOZZO and the LIAISON_MAIL it cannot be solved
i have to say i do not understand your set of boundary conditions
in a previous thread, now disappeared, i wonder why! you claimed you solved it
i would like to know how


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freely available here https://framabook.org/beginning-with-code_aster/

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#13 2022-03-04 09:31:39

jonas loenartz
Member
Registered: 2021-10-01
Posts: 51

Re: LIAISION_MAIL problem

jeanpierreaubry wrote:

@jonas
the mesh that i have downloaded does not contain a 3D group named CERCHIONE
is that a problem with window$ created mesh? i do not know
could you share the mesh you are using

Sorry for my late answer. Yes, I used the same mesh and I saw that there is no CERCHIONE, I stopped the execution after LIAISON_SOLIDE, thats why I had no error.

@Giuseppe Faggiano

your boundary conditions, as M. Aubry mentioned, are indeed a mistery to me, too. Are you modeling only a section of the rim and the hub and try to impose a circular boundary condition on the symmetry-faces?

Jonas

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#14 2022-03-04 10:07:18

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

attached is a .comm file that leads to a successful calculation
it contains comments
and may not be what you are looking for
that largely remains a mystery to me as pointed out by jonas


Attachments:
aster__.comm, Size: 6 KiB, Downloads: 72

consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#15 2022-03-04 11:46:37

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

Thanks everyone for the support. I am following a tutorial to apply it on my model. I am forwarding the link to you to understand what I am doing. In the usual link I shared a Powerpoint of the results I had of the rim alone (even if the stresses of Von Mises do not convince me too much). Thanks Jean for the code you sent me, unfortunately that's not what I'm looking for.


*https://www.caelinux.org/wiki/downloads/docs/PCarrico/CAELINUX_plasticite/index.html*

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#16 2022-03-04 12:03:54

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

what are you looking for?


consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#17 2022-03-04 12:16:49

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

jeanpierreaubry wrote:

what are you looking for?

The study focuses on the plasticization of the rim. For this I set up a non-linear analysis to see how it behaves after passing the enervation sigma

Last edited by Giuseppe Faggiano (2022-03-04 12:18:33)

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#18 2022-03-04 13:24:05

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

the you just simply set it in the file i attached
i made a static analysis as a demonstator

have a look at the results i obtain
and look at you boundary condition
in my opinion they are not right


consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#19 2022-03-07 08:09:03

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

hello

attached is a .comm file which contains some comments to explain what is done where

first of all there are some differences in between Paul CARRICO tutorial and your problem
which should not be overlooked

i changed the boundary conditions to something more representative of the symmetry
as well as the LIAISON_OBLIQUE that were not well defined
this changes the results

i replaced some reference to GROUP_NO by GROUP_MA in the boundary conditions
this  does not change the results it simplifies the number of groups
this could be carried on some further, together with mesh definition
ideally there could not be any GROUP_NO defined at mesh time this can be done in the .comm file

some personal remarks
except in some strategic area your mesh seems to me unnecessarily fine
twice the size would be enough with gains in calculation time and memory usage

Last edited by jeanpierreaubry (2022-03-07 08:10:00)


Attachments:
aster__2.comm, Size: 7.19 KiB, Downloads: 56

consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#20 2022-03-08 00:16:05

Giuseppe Faggiano
Member
Registered: 2021-12-14
Posts: 49

Re: LIAISION_MAIL problem

Thanks so much for the support. Sorry if I answer you late, I've been able to fix some errors. The boundary conditions were wrong, I misapplied the LIAISON_OBLIQUE function, I fixed everything and it seems to me that in terms of displacements the results are correct. I have attached a correct .hdf file. The last step is missing, define a different material for the HUB, unfortunately I can't understand how to recall the material in STAT_NON_LINE. Thanks so much for the support. I got to read your book.
*https://drive.google.com/drive/folders/1BXT9I4ex5UTVCXX3W67bWhIAQKWWUmnm?usp=sharing*

Last edited by Giuseppe Faggiano (2022-03-08 00:16:54)

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#21 2022-03-10 15:39:17

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,829

Re: LIAISION_MAIL problem

like this

A6000 = DEFI_MATERIAU(
	ELAS=_F(E=70000.0,NU=0.3),
	TRACTION=_F(SIGM=SIGM_EPS),
);

another = DEFI_MATERIAU(
	ELAS=_F(E=210000.0,NU=0.3),
	TRACTION=_F(SIGM=SIGM_EPS2),
);

A6000_AS = AFFE_MATERIAU(
	AFFE=(
		_F(GROUP_MA='CERCHIONE',MATER=A6000,),
		_F(GROUP_MA='MOZZO',MATER=another,),
	),
	MAILLAGE=MESH,
	#MODELE=MODELLO, #not necessary
);

Last edited by jeanpierreaubry (2022-03-10 15:39:46)


consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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