Stitching two shell

[shingl]

Hi everyone,

I would like to design a pressure garment using Abaqus, which included to calculate the pressure of the garment to the body. What i found the method is presented by a patent

http://www.google.com/patents/US8355811

The steps shown in the patent document is not clear enough to follow. For example, the [162] is the main description of the stitching process, however, nothing have been shown technically. Therefore, i would like to ask whether anyone know how to do so? I don't know how to stitch two shell during analysis.... Maybe my process is wrong, but i have tried restart the analysis, and add the MPC tie constraint to the points, but it does shown any effect. To test it, i have set a simple example, but it also don't work. Can anyone suggest me some methods or hints? Thanks a lot!

 

[burningDiesel]

You can add contact and uncheck the "allow seperation after contact", you can also try to use "rough" friction to disallow movement in the tangential direction.
Alternatively, you can work with connectors (multiple from each point to the one you want it to stitch with) and define a "lock" (*connector behavior).
The MPC tie works with original coordinates, so you could also import the deformed configuration (in CAE), do the tie constraint, and then apply the stresses using *predefined field from your first simulation. But the other options are less work.

 

[shingl]

Dear sdebock, thanks to your reply. In fact, I also prefer not to restart the analysis, as parts will become orphan mesh if imported the deformed configuration.
The idea of contact seems the easiest, however, a error comes since "Edge-based shell surfaces cannot be used in A *CONTACT PAIR", as what i want is connect two shells by their edges, the idea of friction can not be applied in this experiment, but this may work in my other experiment, thank you very much for your suggestion.
Therefore, I would like to try the other suggestion, the connectors, may i know more about it? As the connector works like constraints, which can not be changed in steps, can you give me some hints how to use it?
Thank you very much!

 

[burningDiesel]

Try again with contact but use general contact, or node based contact.
The connectors would have to have a behavior *connector stop to let them "lock" once they come close to eachother.

 

[shingl]

Dear sdebock,

Thank you very much for your reply. After looking at your reply, i have tried so many way but it still not okay....It shows errors and aborted the job always....
As the process is running tied, would you please have a look at my inp file to see whether there is any problem?
The link is at

http://goo.gl/GDqtk

Thank you very much!