Meshing textile for dry fibre analysis

[louisepb]

Hi Anurag,

The problem before was that the yarns were being split along their length by the domain, causing a problem with creating surfaces. I'm afraid that I haven't got around to looking at this yet. Are you sure that this is not the case with your current textile? If not could you send me your script and I'll try and see what the problem is.

Best regards,
Louise

[anuragdixitiitd]

Hi Louise,
I am able to adjust the domain as they no far being split along their length, but my issue is to achieve the shear behaviour of weave as it is as depicted in fig(a) and for that the surface creation remains the problem. Sometimes it is partially creating surface definitions and sometimes it is absolutely not creating at all, as discussed for the case in my previous thread.
If i adjust the domain as suggested by you in the previous thread picture everything goes ok.
Means why it is not able to create the surfaces individually for the weave shown in attached figure(a).
I hope I make u understand my problem without irritating you.
Sincere Regards
Anurag

[louisepb]

Hi Anurag,

As I said before there is a bug in the code which means that surfaces are not generated if the domain splits the yarns lengthways. As yet I haven't had time to investigate this.

I don't really understand why there is a problem with shifting the domain. As long as the domain covers one repeat of your textile then the periodic boundary conditions should give you the same answer.

Best regards,
Louise

[anuragdixitiitd]

Hi Louise,
Fine there is no problem.
Best Regards
Anuarg

[dyeyanie]

Hi Louise,

I have a problem here when I exporting my geometry with dry-fibre meshing. I got a warning which saying :
*** WARNING: TexGen was unable to create contact definitions automatically
*** because the textile is not of type CTextileWeave

Fyi, I generated my geometry by running the script. How could I solve this matter? Many thanks.

Yanie

[louisepb]

Hi Yanie,

In order to generate contact definitions TexGen uses the information stored in the CTextileWeave class. If you generate your textile using the CTextileWeave class (or a class derived from it) in your script then the contact definitions will be generated. If you just use the CTextile class then you will have to generate any contacts that you want in your .inp file manually.

If you have used the CTextileWeave class and the contacts aren't generated then please send me your script and I'll try and work out what the problem is.

Hope that helps,
Louise

[dyeyanie]

Thanks Louise,

It works now. One more thing, I just wonder the section setting with CtextileWeave. Is it an ellipse shapre is set as default? Or do I need to reassign them in GUI?

Yanie

[louisepb]

Hi Yanie,

If you have used the refine option the sections will be polygon sections (which you can't edit using the GUI but can reassign to a different section shape. To change the polygons you would need to either do it from a script or edit the tg3 file). Without refinement they will be ellipses.

Louise

[dyeyanie]

Hi Louise,

I would like to impose a unixial tension load to my dry woven model. What should I put in the X, Y, and Z scale? Previously, I put 1.1,0,0 and I get a negative load in my dummy 2. Suppose, there is no load there, right?

Yanie.

[louisepb]

Hi Yanie,

Apologies for the delay in replying - I have been on holiday.

The x,y and z scales will give you deformations in the specified direction. Putting 1.1, 0, 0 will effectively give you a uniaxial tension in the x direction.

Louise

[dyeyanie]

Hi Louise,

How about if I let the scale as 1.1, 1.0, 1.0? As for biaxial, I should put them for instance as 1.1, 1.1, 0?

Yanie

[louisepb]

Hi Yanie,

Sorry, I didn't notice in my previous reply that you had 0s in the scale, rather than 1.0, for axes with no deformation. So, for biaxial you will need something like (1.1, 1.1, 1.0). Basically whatever you want your deformations to be for the x, y and z axes respectively.

Louise

[dyeyanie]

Hi Louise,

I don't get you clearly... If you said, to get biaxial loading I have to put (1.1, 1.1, 1.0) so means that I need to put (1.1, 1.0, 1.0) for uniaxial , right? Which to my understand, we don't want any external deformation in Y and Z axes. I found that, if I put 1.1, 0, 0, I'll get negatives load in my Y and Z axes which I think is similar to compression loads.

Am I right?

Yanie

[louisepb]

Hi Yanie,

A scale of 1.0 will specify no deformation in that axis. Any value of less than one will give you a compression so, yes, using 0 will give compression.

The scales are applied in the section of the inp file with the heading "*** Constrain the nodes closest to the geometrical center of each yarns"
The displacement is calculated using "Displacement = Deformation * Position - Position" for each axis where Deformation is the specified scale for that axis.

Louise

[dyeyanie]

ok, clear now. Many thanks Louise!!

Yanie