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## #1 Re: Code_Aster usage » Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE) » 2020-10-22 10:34:33

hkboondoggle wrote:

Could you please explain the reason why slave surface mesh has to be finer then that of master?

maybe this

code-aster.org/doc/default/en/man_u/u2/u2.04.04.pdf (copy and paste in your browser)

from 2.2.3 Case general

to 2.2.7 Quality of the grid

## #2 Re: Code_Aster usage » How to increase the speed » 2020-10-14 11:11:42

Only for Italian User

Troll o è davvero Clemente ???

napoli.repubblica.it/dettaglio/tangenti-bufera-su-mastella-in-un-file-la-lista-di-raccomandati/1755990/2

## #3 Re: Code_Aster usage » How to increase the speed » 2020-10-13 09:52:26

Clement M wrote:

Yes it is basicly what I want to do.
To explain you a bit better I am in intership and my goal is to simulate the expansion of a flywheel. Some experiments with the same flywheel at different speed were made and my aim is to be as close as possible from this results. But before working with this complex object I am simulating a simple cylinder with an hole, so a pipe, in two dimension.
It seems to work fine but I can t do a lot of revolution at high speed (my goal is 20 000 rpm) because I have convergence problem. So I need to have an extremely small timestep and I have problem with memory.
So to solve this problem and to be closer from the experiments I am trying to have a speed which goes from 0 to 20 000 rpm in few seconds and not directly 20 000 rpm during the whole simulation. As I didn t have the speed in my rotation formula I was trying to change an other parameter. I try with dtheta but as it wasn t a scalar anymore it wasn t recognized in the formula and it didn t work. So I don t really know what to do. I hope you will understand better my problem.
What you send me seems way better but I don t understand why cos(t) and how to define n(dt) in code aster.
Thanks again for your help I really appreciate it.

Formula 1 or MotoGP flywheel ???? :-D

## #4 Re: Code_Aster usage » How to increase the speed » 2020-10-12 12:26:25

Hi

good news :

YES is possible to "concatenate" med file of stage 1 with med file of stage 2. imposeign how start coditions of stage 2 the final conditions of stage 1.

resnonla = DYNA_NON_LINE(CHAM_MATER=fieldmat,
COMPORTEMENT=_F(DEFORMATION='SIMO_MIEHE',
RELATION='VMIS_ISOT_LINE'),
CONVERGENCE=_F(ITER_GLOB_MAXI=30),
>>>>>>>>>> ETAT_INIT=_F(EVOL_NOLI=resnonl),<<<<<<<<<<<<<<<<<<<<<
EXCIT=_F(CHARGE=rotaa),
INCREMENT=_F(LIST_INST=timesa),
MODELE=model,
NEWTON=_F(MATRICE='TANGENTE',
PREDICTION='TANGENTE'),
>>>>>>>>>>RESULTAT=resnonl,<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
SCHEMA_TEMPS=_F(FORMULATION='DEPLACEMENT',
SCHEMA='HHT'),
SOLVEUR=_F(METHODE='MUMPS'))

here the video :

(for my videos i used small values of acceleration velocity and time range, for a rapid computation)

## #5 Re: Code_Aster usage » How to increase the speed » 2020-10-12 09:56:08

Today i arrived here :

thinking :

for csv format , i think, depend from which table you ask to the code :-)

i'm reserving time for study.

## #6 Re: Code_Aster usage » How to increase the speed » 2020-10-12 09:20:13

Clement M wrote:

I don t understand how to print it sorry

i'm studing "the problem"

see attachment :-D

## #7 Re: Code_Aster usage » How to increase the speed » 2020-10-12 00:50:55

i don't know.

BUT

observe :

resnonla = DYNA_NON_LINE(CHAM_MATER=fieldmat,
COMPORTEMENT=_F(DEFORMATION='SIMO_MIEHE',
RELATION='VMIS_ISOT_LINE'),
CONVERGENCE=_F(ITER_GLOB_MAXI=30),
EXCIT=_F(CHARGE=rotaa),
INCREMENT=_F(LIST_INST=timesa),
MODELE=model,
NEWTON=_F(MATRICE='TANGENTE',
PREDICTION='TANGENTE'),
RESULTAT=resnonl,
SCHEMA_TEMPS=_F(FORMULATION='DEPLACEMENT',
SCHEMA='HHT'),
SOLVEUR=_F(METHODE='MUMPS'))

resnonla = CALC_CHAMP(reuse=resnonla,
CRITERES=('SIEQ_ELGA', ),
RESULTAT=resnonla)

IMPR_RESU(FORMAT='MED',
RESU=_F(RESULTAT=resnonla),
UNITE=2)
-----------------------------------------------------------------------------------------------------------------
in resnonla at the voice : RESULTAT =resnonl, you use the datas of first stage
-----------------------------------------------------------------------------------------------------------------
IMPR_RESU(FORMAT='MED',
RESU=_F(RESULTAT=resnonla),
UNITE=2)
-----------------------------------------------------------------------------------------------------------------
here you "print" the data of second stage where into there is the data of first stage.

i attend confirm like you :-)

## #8 Re: Code_Aster usage » How to increase the speed » 2020-10-11 15:26:24

explaining better

1047 = 2*pi*20000 /(60*2) -> angular acceleration betveen 0;2 => 1047*INST = angular velocity => 1047*INST*INST = angle

1047*2 = angular velocity (constant) between 2:5 => 1047*2*INST = angle

p.s.

atan (value) = angle

:-)

## #9 Re: Code_Aster usage » How to increase the speed » 2020-10-11 08:10:52

errata corrige :

xx = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+1047*INST*INST)-X')

yy = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+1047*INST*INST)-Y')

xxa = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+1047*2*INST)-X')

yya = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+1047*2*INST)-Y')

maybe???? :-)

## #10 Re: Code_Aster usage » How to increase the speed » 2020-10-11 07:46:39

sameer21101970 wrote:

you are forgetting velocity.
rpm should be define in terms of peripheral velocity r/sec.
xx & yy formula DHT =419 define for how many degree of rotation you want to analyse result.

i'm thinking which DTH is angulare velocity, see an other way attached here :-)

## #11 Re: Code_Aster usage » How to increase the speed » 2020-10-10 23:51:02

try with two stages :

tstep = 1

mesh = LIRE_MAILLAGE(FORMAT='MED',
UNITE=20)

model = AFFE_MODELE(AFFE=_F(MODELISATION=('3D', ),
PHENOMENE='MECANIQUE',
TOUT='OUI'),
MAILLAGE=mesh)

ys = DEFI_CONSTANTE(VALE=210000000000.0)

ps = DEFI_CONSTANTE(VALE=0.3)

ds = DEFI_CONSTANTE(VALE=8000.0)

steel = DEFI_MATERIAU(ECRO_LINE=_F(D_SIGM_EPSI=1100000000.0,
SY=700000000.0),
ELAS_FO=_F(E=ys,
NU=ps,
RHO=ds))

fieldmat = AFFE_MATERIAU(AFFE=_F(MATER=(steel, ),
TOUT='OUI'),
MODELE=model)

listr = DEFI_LIST_REEL(DEBUT=0.0,
INTERVALLE=_F(JUSQU_A=2.0,
PAS=tstep))

times = DEFI_LIST_INST(DEFI_LIST=_F(LIST_INST=listr,
PAS_MINI=1e-12),
METHODE='AUTO')

xx = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+419*INST*INST)-X')

yy = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+419*INST*INST)-Y')

xxa = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+419*INST)-X')

yya = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+419*INST)-Y')

listra = DEFI_LIST_REEL(DEBUT=2.0,
INTERVALLE=_F(JUSQU_A=5.0,
PAS=tstep))

timesa = DEFI_LIST_INST(DEFI_LIST=_F(LIST_INST=listra,
PAS_MINI=1e-12),
METHODE='AUTO')

rota = AFFE_CHAR_MECA_F(DDL_IMPO=_F(DX=xx,
DY=yy,
GROUP_NO=('rot', )),
MODELE=model)

rotaa = AFFE_CHAR_MECA_F(DDL_IMPO=_F(DX=xxa,
DY=yya,
GROUP_NO=('rot', )),
MODELE=model)

resnonl = DYNA_NON_LINE(CHAM_MATER=fieldmat,
COMPORTEMENT=_F(DEFORMATION='SIMO_MIEHE',
RELATION='VMIS_ISOT_LINE'),
CONVERGENCE=_F(ITER_GLOB_MAXI=30),
EXCIT=_F(CHARGE=rota),
INCREMENT=_F(LIST_INST=times),
MODELE=model,
NEWTON=_F(MATRICE='TANGENTE',
PREDICTION='TANGENTE'),
SCHEMA_TEMPS=_F(FORMULATION='DEPLACEMENT',
SCHEMA='HHT'),
SOLVEUR=_F(METHODE='MUMPS'))

resnonl = CALC_CHAMP(reuse=resnonl,
CRITERES=('SIEQ_ELGA', ),
RESULTAT=resnonl)

IMPR_RESU(FORMAT='MED',
RESU=_F(RESULTAT=resnonl),
UNITE=80)

resnonla = DYNA_NON_LINE(CHAM_MATER=fieldmat,
COMPORTEMENT=_F(DEFORMATION='SIMO_MIEHE',
RELATION='VMIS_ISOT_LINE'),
CONVERGENCE=_F(ITER_GLOB_MAXI=30),
EXCIT=_F(CHARGE=rotaa),
INCREMENT=_F(LIST_INST=timesa),
MODELE=model,
NEWTON=_F(MATRICE='TANGENTE',
PREDICTION='TANGENTE'),
RESULTAT=resnonl,
SCHEMA_TEMPS=_F(FORMULATION='DEPLACEMENT',
SCHEMA='HHT'),
SOLVEUR=_F(METHODE='MUMPS'))

resnonla = CALC_CHAMP(reuse=resnonla,
CRITERES=('SIEQ_ELGA', ),
RESULTAT=resnonla)

IMPR_RESU(FORMAT='MED',
RESU=_F(RESULTAT=resnonla),
UNITE=2)

## #12 Re: Code_Aster usage » How to increase the speed » 2020-10-10 13:15:41

ha!

i'm unemployed,

i spend my time NOT for do criminal's things
BUT
studing something.

Can you tell me if the study with that command file converge ???

My p.c. stops the computation it goes crazy with memory :-D

## #13 Re: Code_Aster usage » How to increase the speed » 2020-10-09 20:29:42

hi,

with this command file the simulation runs.

tstep = 1

mesh = LIRE_MAILLAGE(FORMAT='MED',
UNITE=20)

model = AFFE_MODELE(AFFE=_F(MODELISATION=('3D', ),
PHENOMENE='MECANIQUE',
TOUT='OUI'),
MAILLAGE=mesh)

ys = DEFI_CONSTANTE(VALE=210000000000.0)

ps = DEFI_CONSTANTE(VALE=0.3)

ds = DEFI_CONSTANTE(VALE=8000.0)

steel = DEFI_MATERIAU(ECRO_LINE=_F(D_SIGM_EPSI=1100000000.0,
SY=700000000.0),
ELAS_FO=_F(E=ys,
NU=ps,
RHO=ds))

fieldmat = AFFE_MATERIAU(AFFE=_F(MATER=(steel, ),
TOUT='OUI'),
MODELE=model)

listr = DEFI_LIST_REEL(DEBUT=0.0,
INTERVALLE=_F(JUSQU_A=5.0,
PAS=tstep))

times = DEFI_LIST_INST(DEFI_LIST=_F(LIST_INST=listr,
PAS_MINI=1e-07),
METHODE='AUTO')

xx = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+419*INST*INST)-X')

yy = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+419*INST*INST)-Y')

rota = AFFE_CHAR_MECA_F(DDL_IMPO=_F(DX=xx,
DY=yy,
GROUP_NO=('rot', )),
MODELE=model)

resnonl = DYNA_NON_LINE(CHAM_MATER=fieldmat,
COMPORTEMENT=_F(DEFORMATION='SIMO_MIEHE',
RELATION='VMIS_ISOT_LINE'),
CONVERGENCE=_F(ITER_GLOB_MAXI=30),
EXCIT=_F(CHARGE=rota),
INCREMENT=_F(LIST_INST=times),
MODELE=model,
NEWTON=_F(MATRICE='TANGENTE',
PREDICTION='TANGENTE'),
SCHEMA_TEMPS=_F(FORMULATION='DEPLACEMENT',
SCHEMA='HHT'),
SOLVEUR=_F(METHODE='MUMPS'))

resnonl = CALC_CHAMP(reuse=resnonl,
CRITERES=('SIEQ_ELGA', ),
RESULTAT=resnonl)

IMPR_RESU(FORMAT='MED',
RESU=_F(RESULTAT=resnonl),
UNITE=80)

p.s :

419 = 2*pi*20000/ (60*5)

5 = time end

the geometry is attached
and you must introduce in time camp NOT 10 but 24 (h).

Units : Interational Standards

## #14 Re: Code_Aster usage » How to increase the speed » 2020-10-09 18:41:42

you can try with a simple linear function :

DTH= constant*INST

using DEFI_LIST_REEL

imposing in DEFI_LIST_INST a very little PAS_MINI in authomatic mode

probably, if computer's memory supports the computation, you can go out from your problem

:-)

## #15 Re: Code_Aster usage » How to increase the speed » 2020-10-09 17:22:46

i wrote cost = constant, n(t) for say rpm like a function of time, strictly : constant+rpm(t)

thinking :

if is possible in code aster introduces a formula into an other formula you can resolve your problem,

example :

tournex = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*cos(atan2(Y,X)+DTH*INST)-X',
DTH=DTH)

tourney = FORMULE(NOM_PARA=('X', 'Y', 'INST'),
VALE='sqrt(X*X+Y*Y)*sin(atan2(Y,X)+DTH*INST)-Y',
DTH=DTH)

DTH= omega = 2*pi*rpm/60

rpm = function(time) -> function that exist between 0 and 20000, function that you must create :-)

can this for you right ??? :-)

see attachement

## #17 Re: Code_Aster usage » How to increase the speed » 2020-10-09 09:59:38

Clement M wrote:

Ok thanks a lot I will try it. But to be closer for my experimental plots I think I will need to have an increasing speed anyway. Do you know how I should do it ?

i don't understand good the problem : see the picture attached where there is which you do

## #18 Re: Code_Aster usage » How to increase the speed » 2020-10-08 15:52:59

for me your problem is the dscretization of time steps, you should introduce something similar of PAS_MINI.

## #19 Re: Code_Aster usage » Twin pistons dynamic simulation » 2020-08-29 09:39:15

sameer21101970 wrote:

I use Code_aster to not commit suicide from boredom.

## #20 Re: Code_Aster usage » Twin pistons dynamic simulation » 2020-08-28 23:56:36

try this p.step (attached)

## #21 Re: Code_Aster usage » Twin pistons dynamic simulation » 2020-08-28 19:29:29

attached .step files and new mesh.

Tell me if you have problems

## #22 Re: Code_Aster usage » Twin pistons dynamic simulation » 2020-08-26 19:02:41

A pleasure :

if you have the names and surnames of those who claim that I am (as of today, from tomorrow I don't know) paid to use Code_Aster or in general for my Internet activity,

Please give them to me and I'll sue them.

Signed

Maurizio Dr. Buggin

## #23 Re: Code_Aster usage » Twin pistons dynamic simulation » 2020-08-26 18:35:49

here in code_aster_Italia

code-aster.it/forum/topic/sulle-potenzialita-di-code_aster/#postid-361

(copy and paste in your browser)

mib
Replies: 9