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#1 Re: Code_Aster usage » contact reaction force » 2023-03-19 14:51:44

another way is

conta1 = POST_RELEVE_T(ACTION=_F(GROUP_MA=('contact', ),

                                 INTITULE='contact',

                                 NOM_CHAM='CONT_NOEU',

                                 NOM_CMP=('RNZ', ),

                                 OPERATION=('MOYENNE_ARITH', ),

                                 RESULTAT=STA_NL))

and then multiply it by the number of nodes

#2 Re: Code_Aster usage » contact reaction force » 2023-03-19 14:31:54

hello, yes I already figured that out (with help of chatGPT)
But why there is no build in function to compute sum?

conta2 = POST_RELEVE_T(ACTION=_F(GROUP_NO=('contact', ),

                                 INTITULE='contact',

                                 NOM_CHAM='CONT_NOEU',

                                 OPERATION=('EXTRACTION', ),

                                 RESULTAT=STA_NL,

                                 TOUT_CMP='OUI'))

#3 Re: Code_Aster usage » Sugestion to improve documentation translation (with deepl). » 2023-03-18 13:31:30

Hello, I recommend using deepl, it is really better,
for example

MOMENT = (‘DRX’, ‘DRY MARTINI’, ‘DRZ’)                      MOMENT = (‘DRX’, ‘DRY’, ‘DRZ’)

MOYE_NOEUD= / ‘YES’, [DEFECT]                                 MOYE_NOEUD= / ‘YES’, [DEFAULT]


if you download their translator, with just crtl+F8 you select the solver message and it is translated to english in a second

#4 Re: Code_Aster usage » Structure Optimization with Code_Aster » 2023-03-18 10:35:47

Hello, changing the beginning to

#LOADING MODULES
#import sys
#sys.path.append(r'C:\Users\AppData\Local\code_aster\v2021\14.8\lib\aster\Utilitai' )

#from code_aster.MacroCommands.Utils import partition
from code_aster.MacroCommands.Utils.partition import *

#from Utilitai.partition import *
#from partition import *
#from Table import*
import numpy as N
# import Numeric as N
import math

worked for me with 15.4

however only to 5th iteration, then it takes really long to solve.

#5 Re: Code_Aster usage » contact reaction force » 2023-03-18 10:07:52

there is nothing about computing sum of RN

#6 Re: Code_Aster usage » contact reaction force » 2023-03-17 14:00:24

there is no part 3.9

However if you mean this:

#comment: conta = POST_RELEVE_T(ACTION=_F(GROUP_NO=('contact_tube', ),
#comment:                                 INTITULE='contact',
#comment:                                 NOM_CHAM='CONT_NOEU',
#comment:                                 OPERATION=('EXTRACTION', ),
#comment:                                 RESULTANTE=('RNY', ),
#comment:                                 RESULTAT=STA_NL))

Doesn't work

#7 Code_Aster usage » contact reaction force » 2023-03-16 23:37:41

jacob
Replies: 7

Hello,
how to calculate reaction force from contact?

For force it is

reaction = POST_RELEVE_T(ACTION=_F(GROUP_NO=('target_bumper', ),
                                   INTITULE='reaction',
                                   NOM_CHAM='FORC_NODA',
                                   OPERATION=('EXTRACTION', ),
                                   RESULTANTE=('DX', 'DY', 'DZ'),
                                   RESULTAT=FORC))

But how to do that for contact?
I found that it should be done by VALE_CONT, but it doesn't exist.

#9 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-14 21:16:11

spod wrote:
miib wrote:

the value is 1.46e+11

That is quite nice, how did you realise that a mesh of this kind would help to reach a closer value?


There is no closer or analytical value! With next refinement the value will be higher and higher. It is singularity!

#10 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-13 09:42:48

this is the comm which also calculates total load automatically and works even in graphical mode in salomemeca (The variable is highlighted in red, because of the duplicate name, but it is not a problem )

#11 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-13 08:44:02

You got 104000 MPa probably because you used linear elements.

However, if you want to compare results from different software, it would be better to use same mesh and focus on some converged value ( for example stress concentration in a hole in a plate) and not singularity.

The different values of VMIS is probably caused by different interpolation and averaging.

#13 Re: Salome-Meca usage » Results don't match calculation » 2023-03-11 15:15:52

load0 = AFFE_CHAR_MECA(identifier='7:1',

                       FORCE_ARETE=_F(FX=100.0,

                                      GROUP_MA=('loadend', )),

                       MODELE=model)

is actually 100 N / mm so if you want 100 N you have to enter 100 / edge length

#14 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-11 15:10:14

bafybeid6d6irdkqjivza5lnhjiingxegopwc7ttirultkoispvnb3lovbm.ipfs.dweb.link/RQ_1_.zip

#15 Re: Salome-Meca usage » Can't write results file [SOLVED] » 2023-03-11 13:23:07

you restrained only translation DOFs, but you are using shell

fixed = AFFE_CHAR_MECA(DDL_IMPO=_F(DRX=0.0,
                                   DRY=0.0,
                                   DRZ=0.0,
                                   DX=0.0,
                                   DY=0.0,
                                   DZ=0.0,
                                   GROUP_MA=('supportend', )),
                       MODELE=model)


worked.

#17 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-11 11:57:49

or it could be caused by how VMIS is computed, before or after averaging.

Could you post sigma X (axial) from ansys?

#18 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-11 11:07:24

The difference with ansys 145 000 MPa may be caused by different averaging or rounding, but from physical point of view it is just a singularity, so no need to worry about it too much.

#19 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-10 11:36:23

I thing you are talking about RBE3, but it brings other issues then just doing F/A

It can be also done FORCE_NODALE/ number_of_nodes but the distribution won't be smooth. (that is basically what RBE3 will do)

#20 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-10 10:25:16

I guess I have found quite a nice solution how to do that using this post

Easy question: how to set a force on a surface?

The advantage is that Stage_1 and Stage_3 can be in graphical mode.

#21 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-10 10:09:07

probably the difference is caused by linear and quadratic mesh

#22 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-09 23:24:05

youtube.com/watch?v=vOfexbjNutE&list=PLBwQ5Llf4Q_Vj8xKcxsbzIfdqrtzcHLbe&index=32

#23 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-09 22:54:04

no, i didn't investigate it thoroughly, but I think the pressure has to integrate and then convert to nodal values

#24 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-09 22:22:58

I understand that it is how the numerics work, just wonder why there is no FORCE TOTAL

it could be done just like doing something like this before affe_cara_meca

VOL= POST_ELEM(INST=(0.0, ),
                   INTEGRALE=_F(GROUP_MA=('Fx', ),
                                NOM_CHAM='DEPL',
                                NOM_CMP=('DX', ),
                                TYPE_MAILLE='2D'),
                   MODELE=model,
                   RESULTAT=resnonl)

IMPR_TABLE(NOM_PARA=('VOL', ),
           TABLE=table0,
           UNITE=3)

and then FORCE_FACE / VOL




I can do
VOL= POST_ELEM(INST=(0.0, ),
                   INTEGRALE=_F(GROUP_MA=('Fx', ),
                                NOM_CHAM='DEPL',
                                NOM_CMP=('DX', ),
                                TYPE_MAILLE='2D'),
                   MODELE=model,
                   RESULTAT=resnonl)

and then copy paste, but it is the same as using salome or whatever
or create dummy model and use python but make thing quite complicated for very basic thing.

#25 Re: Code_Aster usage » Failure in validating Code_Aster with ANSYS » 2023-03-09 21:21:42

could you specify more clearly what you have in mind?

I just wonder why there is at least a function to compute area of the surface if there is no TOTAL FORCE like in other GUIs.
Measure the area is no such problem, it just takes a little bit of time, but it is quite very common thing.