Menu

Discussion Forum

New Discussion
Filtrer

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Meaning of equation in solid mechanics and stationary study

Posted 15 juin 2018, 03:42 UTC−4 3 Replies

DoWon Heo
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

hello In my model, i used solid mechanics and stationary solver.

in solid mechanics, i can see the eqauion, but i cannot understand the meaning of that.

the equation is 0= del FS + Fv , F = I + del u in document, there is no mention about S and v, where can i get the information of this value?

Attachments:

3 Replies Last Post 19 juin 2018, 11:16 UTC−4
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 15 juin 2018, 09:59 UTC−4
Updated: 6 years ago 16 juin 2018, 02:28 UTC−4

Hi,

'S' is the stress. Basically this is the equation of motion: divergence of stress equals the volume force. If you look at the equation in the Linear Elastic node, you will see the definition of 'S'.

To be more specific, 'S' is the 2nd Piola-Kirchhoff stress, so 'FS' (where F is the deformation gradient) is the 1st Piola-Kirchhoff stress.

Regards,
Henrik

-------------------
Henrik Sönnerlind
COMSOL
Hi, 'S' is the stress. Basically this is the equation of motion: divergence of stress equals the volume force. If you look at the equation in the Linear Elastic node, you will see the definition of 'S'. To be more specific, 'S' is the 2nd Piola-Kirchhoff stress, so 'FS' (where F is the deformation gradient) is the 1st Piola-Kirchhoff stress. Regards, Henrik
DoWon Heo
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 18 juin 2018, 20:22 UTC−4

Thank you for your reply.

Can I ask about more detail?

In equation view, dotted line is under the equation. what is the mening of this line? and i cannot find the meaning of v.

Thank you for your reply. Can I ask about more detail? In equation view, dotted line is under the equation. what is the mening of this line? and i cannot find the meaning of v.
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 19 juin 2018, 11:16 UTC−4

Hi,

The dotted line indicates the part of the equation which is mainly affected by the inputs in a certain feature. If you add a Body Load node, you will find Fv underlined, because that is where the volume force is added. In that case 'v' stands for 'volume', but such decorators must be understood in their own context.

The equations shown in the Equation sections should be considered as conceptual at best. They are just an indication of what a certain feature does, not a complete description of it. For that, you should refer to the documentation.

Regards,
Henrik

-------------------
Henrik Sönnerlind
COMSOL
Hi, The dotted line indicates the part of the equation which is mainly affected by the inputs in a certain feature. If you add a Body Load node, you will find Fv underlined, because that is where the volume force is added. In that case 'v' stands for 'volume', but such decorators must be understood in their own context. The equations shown in the Equation sections should be considered as conceptual at best. They are just an indication of what a certain feature does, not a complete description of it. For that, you should refer to the documentation. Regards, Henrik

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content