Menu

Discussion Forum

New Discussion
Filtern

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.

Modeling cloth

Posted 21.01.2019, 10:37 GMT-5 Structural & Acoustics 3 Replies

Ke Wu
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi there,

I have a problem modelling a piece of cloth in COMSOL. The key feature of cloth is that it has no bending stiffness or out-of-plane shear stiffness. Could you tell me how to set the right material for the cloth?

Thanks so much, Ke Wu

3 Replies Last Post 25.01.2019, 02:17 GMT-5
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 22.01.2019, 03:43 GMT-5

Hi,

For cloth (and other thin layers with negligible bending stiffness), you need to use the Membrane interface.

However, be warned: It is difficult to obtain convergence in such models, since in real life wrinkles tend to develop unless the two in-plane principal stresses are positive everywhere. A geometrically nonlinear analysis with some initial stress which induces tension in the first iterations is a minimum requirement.

Regards,
Henrik

-------------------
Henrik Sönnerlind
COMSOL
Hi, For cloth (and other thin layers with negligible bending stiffness), you need to use the Membrane interface. However, be warned: It is difficult to obtain convergence in such models, since in real life wrinkles tend to develop unless the two in-plane principal stresses are positive everywhere. A geometrically nonlinear analysis with some initial stress which induces tension in the first iterations is a minimum requirement. Regards, Henrik
Ke Wu
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 23.01.2019, 06:49 GMT-5

Thank you so much！

Can I use shell interface instead considering membrane is so hard to converge？

What I am modeling is an airtight cloth with inner pressure inside.

The idea is to set a prescribed distance at its center to get its corresponding reaction force.

I've attached 2 screen shots below.

Thanks in advance, Ke Wu

Thank you so much！ Can I use shell interface instead considering membrane is so hard to converge？ What I am modeling is an airtight cloth with inner pressure inside. The idea is to set a prescribed distance at its center to get its corresponding reaction force. I've attached 2 screen shots below. Thanks in advance, Ke Wu

Attachments:

Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 6 years ago 25.01.2019, 02:17 GMT-5

Hi,

You can use the Shell interface. The reason not to do that is that as the bending stiffness gets smaller, the numerics gets more and more ill-conditioned. But as long as the solver does not throw warnings or errors at you, a shell solution will work. Due to the bending stiffness there will be no tendency to wrinkling.

Regards,
Henrik

-------------------
Henrik Sönnerlind
COMSOL
Hi, You can use the Shell interface. The reason not to do that is that as the bending stiffness gets smaller, the numerics gets more and more ill-conditioned. But as long as the solver does not throw warnings or errors at you, a shell solution will work. Due to the bending stiffness there will be no tendency to wrinkling. 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