#1 2021-12-08 02:50:21

mu

Member

Registered: 2021-12-03

Posts: 32

[SOLVED] heat shock

Hello,

I've observed an unexpected heat shock in my transient thermal analysis .

Initial temperature of two solids: 30 、10

When time is less than 50 senconds, the max temperature is bigger than 30.

I have tried to use 3D_DIAG modelisation,  but heat shock still exist.

I simulate the model with SolidWorks and I get a correct result without heat shock .

Salome result

SolidWorks result

Last edited by mu (2021-12-10 08:17:50)

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RichardS

Member

From: Munich, Germany

Registered: 2010-09-28

Posts: 563

Website

Re: [SOLVED] heat shock

Hi, for thermal shock applications it is recommended to use 3D_DIAG elements, as its known that full integration elements have the tendency to cause numerical oscillations in the temoerature.
See for ecxample in the training materials here Slide 8:
https /www.code-aster.org/V2/UPLOAD/DOC/Formations/06-thermal_analysis.pdf

Best,
Richard

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Richard Szoeke-Schuller
Product Management
www.simscale.com
We are hiring! https://www.simscale.com/jobs/

mu

Member

Registered: 2021-12-03

Posts: 32

Re: [SOLVED] heat shock

SolidWorks result

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mu

Member

Registered: 2021-12-03

Posts: 32

Re: [SOLVED] heat shock

Hi, Richard

I have tried to use 3D_DIAG, but heat shock still exist.

Hi, for thermal shock applications it is recommended to use 3D_DIAG elements, as its known that full integration elements have the tendency to cause numerical oscillations in the temoerature.
See for ecxample in the training materials here Slide 8:
https /www.code-aster.org/V2/UPLOAD/DOC/Formations/06-thermal_analysis.pdf

Best,
Richard

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demo.comm, Size: 1.95 KiB, Downloads: 152

RichardS

Member

From: Munich, Germany

Registered: 2010-09-28

Posts: 563

Website

Re: [SOLVED] heat shock

Ok, t
hen you can try with a smaller time step or fully implicit time integration (theta=1, default is 0.57).

Best,
Richard

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Richard Szoeke-Schuller
Product Management
www.simscale.com
We are hiring! https://www.simscale.com/jobs/

Volker

Member

From: Chemnitz

Registered: 2016-05-23

Posts: 92

Re: [SOLVED] heat shock

Have you already tested a modelling without using LIAISON_MAIL?
I mean you have only one "real" solid and two zones of solid elements...

mu

Member

Registered: 2021-12-03

Posts: 32

Re: [SOLVED] heat shock

Hi, Richard

Thanks for your help that solved my problem!

my solution:
theta: 0.65+ , timestep 0.5s-

Ok, t
hen you can try with a smaller time step or fully implicit time integration (theta=1, default is 0.57).

Best,
Richard

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Attachments:
demo.comm, Size: 1.84 KiB, Downloads: 149

mu

Member

Registered: 2021-12-03

Posts: 32

Re: [SOLVED] heat shock

Yes, I did. 

Just like you said, LIAISON is not necessary, but it is not the problem.

Thank you all the same.

Have you already tested a modelling without using LIAISON_MAIL?
I mean you have only one "real" solid and two zones of solid elements...