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#1 2012-01-16 22:53:44

pbiagini
Member
From: Hamburg
Registered: 2011-10-28
Posts: 23

MAZARS model

Bonjour,

i'm trying to model a masonry cantilever with a MAZARS model. I have an elastic layer at the base and 40 m of masonry modeled with MAZARS law. It seems that the program doesn't apply the elastic material to the base layer, as indicated in the .comm file. The run stops with the following error:

CR d'execution de JDC en MIXTE
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   ! <S> Exception utilisateur levee mais pas interceptee. !
   ! Les bases sont fermees.                               !
   ! Type de l'exception : error                           !
   !                                                       !
   !  comportement MAZARS non trouvé pour la maille  M3973 !
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
fin CR d'execution de JDC en MIXTE

I cannot understand why it tr to apply the MAZARS law even to the base layer. I post my model

Does anyone has any suggestion ?

Thank you very much


Attachments:
mensola_40m.zip, Size: 43.97 KiB, Downloads: 159

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#2 2012-01-16 22:59:58

sébastien meunier
Member
From: EDF Lab Les Renardières
Registered: 2007-12-02
Posts: 284

Re: MAZARS model

Hello,

MAZARS model exists only for mesh elements group MENSOLA. So you should precise GROUP_MA=MENSOLA under COMP_INCR.

Regards !


Sébastien Meunier - EDF Lab Les Renardières

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#3 2012-01-16 23:04:11

pbiagini
Member
From: Hamburg
Registered: 2011-10-28
Posts: 23

Re: MAZARS model

Thank you very much for your prompt reply Sébastien !!!! I've forgotten to update this field.

Greetings,
Paolo

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#4 2018-12-10 09:25:15

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

Thanks for the post; eventhough 6 years later, I found it useful.

Is there any easy to understand literature for Mazar model's parameters?

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#5 2018-12-10 09:49:14

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

Hello, i am too working in a model with Mazars Model. I found useful the following documents.
If you have further insights in the parametrization of the Model please post them, everything is useful.

u4.43.01.pdf
r7.01.08.pdf
u4.51.11.pdf

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#6 2018-12-10 11:59:30

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

Hi GPSlachs,
Thanks for pointing towards the document. Do you have any related literature or simple worked out example of this model?

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#7 2018-12-10 14:37:42

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

I found interesting the book "Computational Modelling of Concrete Structures" Gunther Meschke, Bernhard Pichler.
You can also look in the code-aster.org documentation for the examples that apply the Mazars Model!
Edit: Also look into this post from 2014 : code-aster.org/forum2/viewtopic.php?id=20005

Last edited by GPSalachs (2019-01-21 07:19:32)

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#8 2019-01-24 15:16:28

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

I have a question regarding the threshold of damage parameter of the Mazars Model.
When the model i am making is in milimetes, does the threshold of damage also need to be calculated in milimeters?

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#9 2019-01-24 15:41:08

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

Today i was running the model with similar case. The model ran only when i made mesh in meters.

Last edited by nirmaljoshi (2019-01-24 15:41:44)

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#10 2019-01-24 15:47:40

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

Did you use pilotage to make your case or DDL_IMPO ?
I am asking because i am trying to make it run by running a force with a ramp function.
Do you apply also self weight with Mazars Model of damage?

Last edited by GPSalachs (2019-01-28 09:50:11)

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#11 2019-02-04 15:40:31

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

If i have a continuous 3D medium and i want to use Mazars Model should i assign with the command AFFE_CARA_ELEM an element to the
medium and while at that should i define an initial analysis with MECA_STATIQUE and a secondary analysis with STAT_NON_LINE to get the
initial linear part and the secondary non linear part of the material right?

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#12 2019-02-06 07:14:11

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

It seems DEFI_MATER_GC (U4.42.07) is easier and convenient to assign Mazer model. Did you try?

Last edited by nirmaljoshi (2019-02-06 07:14:37)

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#13 2019-02-06 10:08:01

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

No haven't tried the DEFI_MATER_GC (U4.42.07) command because i want to remain and understand first better the DEFI_MATER command with mazars model .

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#14 2019-02-06 10:58:29

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

Actually DEFI_MATER_GC is converted to DEFI_MATER during analysis and parameters (used by DEFI_MATER) is printed in the output file e.g.

C30_EC2 = DEFI_MATER_GC(RHO=2400.0,
                          MAZARS=_F(CODIFICATION='BAEL91',
                                    FCJ=3.9000000E7,
                                    UNITE_CONTRAINTE='MPa',),
                          INFO=1,)

== Paramètres of the model MAZARS [MPa] ==
Partie elasticity:
  E =  3.73031085E+06, NU =  2.00000000E-01, RHO =  2.40000000E+03,
Nonlinear part:
  BT =  1.59414953E+00, AC =  2.79632486E-03, SIGM_LIM =  2.34000000E+07, AT =  9.00000000E-01,
   BC =  1.68155462E+01, K =  7.00000000E-01, EPSI_LIM =  3.50000000E-03,
   EPSD0 =  6.27293728E-01,
For information:
  FCJ =  3.90000000E+07, FTJ =  2.34000060E+06, EPSI_C =  2.10253884E-01,
==================================================
/

This method may be useful to understand the material-model although this is like reverse engineering.. wink

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#15 2019-02-07 16:09:32

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

I made some tests indeed it feels easier to do it with the DEFI_MATER_GC command!
On another part tho, the curves one produces in 3D should be taken from the forces and plastic deformations? So like FORCE_REAC and EPSP ? Or am i considering something wrong here? I ask that cause if i take the DX,DY or DZ components they give linear results so i don't know if i am doing wrong somewhere or am i confronting something wrong..

Thank you!

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#16 2019-02-08 14:01:34

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

You can use Linear plus Non-linear analysis with STAT_NON_LIN alone. No need to use MECA_STATIQUE. Also, you need to define COMPORTMENT in STAT_NON_LIN to make the material behave as non-linear.

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#17 2019-02-08 14:14:16

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

Hello, thank you for the response.

My problem is that i define the comportment as MAZARS in STAT_NON_LINE and run the analysis but the DEPL i get is almost always linear and i don't really understand the why.
I am attaching the .comm and .med files for further insights and discussion!

Last edited by GPSalachs (2019-02-09 18:54:18)


Attachments:
comp.tar.xz, Size: 6.56 KiB, Downloads: 25

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#18 2019-02-11 04:49:21

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

1D mazar model in excel with stress strain relationship.


Attachments:
mazarModel.xlsx, Size: 41.91 KiB, Downloads: 30

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#19 2019-02-11 04:50:28

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

I am fining difficulty to converge the calculation. Is there any special way to make the calculation convergent rapidely?

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#20 2019-02-11 08:48:51

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

Yes i am too finding it difficult to make converge this kind of calculation. I do not know if the problem lies with the elements of the mesh (HEXA8) or something else entirely.It could be also some mistake i am making in the STAT_NON_LINE command regarding the comportment or the algorithm for the resolution. I have tried concatenating two STAT_NON_LINE commands or piloting it but the results do not give me the post peak curve.
And i too am trying to understand how to make it converge..

Could it be an orientation issue here? Or maybe the '3D' type of modeling?

Last edited by GPSalachs (2019-02-11 12:09:19)

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#21 2019-02-11 21:08:59

AsterO'dactyle
Administrator
Registered: 2007-11-29
Posts: 234

Re: MAZARS model

Hello,

Softening in your stress-strain curve  => Newton cannot converge after the peak

Have a look on "PILOTAGE " methods (continuation algorithms).


Code_Asterの開発者

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#22 2019-02-12 02:47:17

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

AsterO'dactyle wrote:

Have a look on "PILOTAGE " methods (continuation algorithms).

How to use PILOTAGE in the case of Mazars? For example in the model provided by GPSalachs.

I get error saying while useing the PILOTAGE with deformation.

<EXCEPTION> <CHARGES_39>                                           !
   !                                                                    !
   ! One cannot control in the absence of forces of the type FIXE_PILO.

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#23 2019-02-12 09:19:00

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

The type of forces FIXE_PILO means that you have to select in the loads the FIXE_PILO property without a multiplying function. 
On that end can it be done so i can run the analysis with PILOTAGE from the beginning or should i give for the piloting initial conditions with a beginning STAT_NON_LINE command?
In the event of successive forces do i have to pilot each force separately?

Just a reference thread i found : forum2/viewtopic.php?id=12930

Last edited by GPSalachs (2019-02-12 09:37:41)

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#24 2019-02-14 03:14:12

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 116

Re: MAZARS model

Did you solve the convergence issue? I am still struck with convergence. I found that convergence is more difficult in the tension.

If you found the solution can you please share.

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#25 2019-02-14 09:53:58

GPSalachs
Member
Registered: 2018-03-10
Posts: 81

Re: MAZARS model

Hello,

i am trying the long arc method of piloting. I tried also the PRED_ELAS method because in the ''12-Continuation methods for non-linear analysis'' it is suggested for ''damage'' laws but it doesn't like Mazars model, unless i have to select certain properties to make it work.

For the long arc method now, i saw a Thomas DE SOZA (forum2/viewtopic.php?id=12930) post from a while back that indicates some the use of some properties:

PILOTAGE=_F( TYPE = 'LONG_ARC',   << arc-length method
SELECTION='ANGL_INCR_DEPL',        << how to determine solution when it is not unique, this one selects the one that minimizes the angle on the arc-length
GROUP_NO = 'TOUT_ELT',                      << which dofs to select (usually the whole structure)
NOM_CMP = ('DX', 'DY', 'DZ',),                  << which components (usually all)
ETA_PILO_MAX=5.,                                   << max multiplicative of the load
COEF_MULT = 120.),                                 << the tricky part, it controls how fast you move on the arc-length, it is related to the time step, you should increase its value if you do not get past the snap-back (so as to decrease the increment on the arc-length).

Now i don't completely understand the correct use of these parameters and i am going through the test , fail and retest road.
I have seen some examples of piloting the model of mazar but those use the Deformation piloting method.
As far as the deformation method is concerned, do i have to get an initial state before continuing with the piloting by deformation?

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