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#1 2018-08-23 12:23:41

aitalaini
Member
From: Italia
Registered: 2018-08-23
Posts: 4

mazars problem

Dear all,
I'm trying to use the  mazars model to reproduce a real experiment on mansory, but i have a lot of problem converging that.
I tried all stuff i found on th forum but i have the same problem.
I would like to ask you what is the error i made,
thanks

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#2 2018-09-04 12:57:36

jlf
Member
Registered: 2007-11-22
Posts: 240

Re: mazars problem

Hello,

Not easy to help you. Could you give us, at least, the values of alls the parameters you use?

JLF

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#3 2018-09-09 22:08:11

aitalaini
Member
From: Italia
Registered: 2018-08-23
Posts: 4

Re: mazars problem

sorry i forget the attachment


Attachments:
study.zip, Size: 150.39 KiB, Downloads: 158

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#4 2018-09-14 08:37:33

jlf
Member
Registered: 2007-11-22
Posts: 240

Re: mazars problem

Hi,

It's bizarre.
With only the gravity load, you produce the rupture of the concrete !!
To see the gravity effect, you can create a linear function to apply this load.

Could you check your units and loads values ?

JLF

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#5 2018-09-15 15:08:59

aitalaini
Member
From: Italia
Registered: 2018-08-23
Posts: 4

Re: mazars problem

thanks jlf, the parameter RHO was out of scale, but also with correct unit don't converge.
If you know parameters of mazars  are dimensionless?

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#6 2018-09-24 08:52:34

jlf
Member
Registered: 2007-11-22
Posts: 240

Re: mazars problem

Hi,

yes, the mazars parameters are dimensionless.
BUT you must have the correct unit for your problem. For example m, N, Pa.
Your Young modulus is 1000, for concrete is 32000MPa or 32000E+06Pa.

Did you plot the mazars behavior for unidimensional traction and compression with your parameters ?
With your values, if Young modulus is in MPa the max stress in compression is 0.33MPa.

JLF

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#7 2018-09-27 10:45:18

aitalaini
Member
From: Italia
Registered: 2018-08-23
Posts: 4

Re: mazars problem

theoretically unit of my model is mm, for test on mansory wall. I see some example, but i not understand what i do wrong.

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#8 2018-09-27 12:17:27

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,638

Re: mazars problem

hello

try these more reasonable parameters
E=32000 as suggested by jlf
Bc=1000 as suggested by jlf and in U4.43.01 document
RESI_GLOB_RELA=0.0015
or a PAS varying along time

and Introduce yourself in the relevant section of the forum

jean pierre aubry


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

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#9 2019-06-20 10:07:42

95ims
Member
Registered: 2019-06-16
Posts: 4

Re: mazars problem

Hello,

Did you find a solution to the convergence issue? I am having the same problem with Mazars.

Thanks.

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#10 2019-06-20 11:29:33

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 181

Re: mazars problem

Here is worksheet to calculate mazars parameter by yourself.

Also you can use DEFI_MATER_GC so that you do not need to input each parameters.


Attachments:
mazar_model.ods, Size: 51.24 KiB, Downloads: 64

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#11 2019-06-20 11:31:01

nirmaljoshi
Member
From: Japan
Registered: 2018-10-12
Posts: 181

Re: mazars problem

jlf wrote:

Hi,

Did you plot the mazars behavior for unidimensional traction and compression with your parameters ?

JLF

How do we do that? Can you provide simple example.

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