Meshing textile for dry fibre analysis

[anuragdixitiitd]

Hi, louise,
Nice to see your reply, I cant understand how to download the code from the repository? means where i will find it out? Whether I can change my weave option (no. of warp and weft yarn arrangement) through this code? What about the boundary conditions of that sheared domain built from the code?
By the way when will the release incorporated with shear option will be done.
Sincere Regards
Anurag

[louisepb]

Hi Anurag,

The instructions for building the code from source are on the TexGen website here: http://texgen.sourceforge.net/index.php ... rom_Source The new code enables a weave to be defined exactly as before but with the addition of a shear angle and the option to have the sheared domain. If you then export using the sheared option in the voxel mesh export dialog you will be able to see the resultant boundary conditions in the .inp file.

I am still working on some refinement for the shear textile export and will probably do a new release once I've finished this. Unfortunately I don't know how long it's going to take at the moment!

Best regards,
Louise

[anuragdixitiitd]

Many Thanks

[anuragdixitiitd]

Hi Louise,
When i am running my .inp file for shear loading in ABAQUS command window an error: NO SURFACE FACETS ARE GENERATED FOR SURFACE or NO DATA PROVIDED FOR *SURFACE is occurring for upper and lower portion of the yarns in .dat file. While when seeing the .inp file I can see that surface as well as element definitions are provided to them? Though these definitions are not allotted individually as in case of previously developed non-sheared model. How should I give proper surface definition in this case?
Regards
Anurag

[louisepb]

Hi Anurag,

Did you use the new shear option in the 2D wizard to create your sheared textile? Are you using the dry textile export? If so then my guess is that this is a problem caused by the use of the sheared textile in the dry fibre export in which case I need to take a look at this as it's probably something that I've overlooked. I'm not in the office tomorrow but I'll take a look at this on Wednesday.

Louise

[anuragdixitiitd]

hi Louise,
Thanks for your reply!! What I have done is that created .PY file of sheared fabric with sheared domain and then run the script in TexGen instead of creating sheared fabric and domain from 2D wizard as it is not available in version 3.5.3 of Texgen, then I exported using ABAQUS dry fiber with compression plates to see its nature under dual loading mode. After that i run .inp file from ABAQUS command window and got the errors as I mentioned in my previous thread. Basically the it is not identifying the allocated surfaces correctly as they are not assigned individually. I hope I make you my problem understand??
Sincere Regards
Anurag

[louisepb]

Hi Anurag,

Would it be possible for you to send me your script so that I can see exactly what's going on. I have tried running an Abaqus job with a sheared textile created using the wizard and it seems to run ok. I do need to double check that the output to the .inp file is correct for the sheared domain with the dry fibre output - something I'd overlooked so thanks for bringing it to my attention!

Best regards,
Louise

[anuragdixitiitd]

Hi Louise,
Sorry for delay in reply as I was out of my office. The script which I am trying to run for shear fabric with shear domain is as under:


from math import *

# Create a textile
Textile = CTextile()

# Create a python list containing 4 yarns
Yarns = [CYarn(), CYarn(), CYarn(), CYarn()]

# Define some constants that will be used in further calculations
spacing = 0.25
height = 0.038


shearAngle = pi/15
twistAngle = shearAngle

shearOffset = spacing*sin(shearAngle)


# Add nodes to the yarns to describe their paths, these are the sheared node positions
Yarns[0].AddNode(CNode(XYZ(0, 0, 0)))
Yarns[0].AddNode(CNode(XYZ(spacing, shearOffset, height)))
Yarns[0].AddNode(CNode(XYZ(2*spacing, 2*shearOffset, 0)))

Yarns[1].AddNode(CNode(XYZ(0+shearOffset, spacing, height)))
Yarns[1].AddNode(CNode(XYZ(spacing+shearOffset, spacing+shearOffset, 0)))
Yarns[1].AddNode(CNode(XYZ(2*spacing+shearOffset, spacing+2*shearOffset, height)))

Yarns[2].AddNode(CNode(XYZ(0, 0, height)))
Yarns[2].AddNode(CNode(XYZ(shearOffset, spacing, 0)))
Yarns[2].AddNode(CNode(XYZ(2*shearOffset, 2*spacing, height)))

Yarns[3].AddNode(CNode(XYZ(spacing, 0+shearOffset, 0)))
Yarns[3].AddNode(CNode(XYZ(spacing+shearOffset, spacing+shearOffset, height)))
Yarns[3].AddNode(CNode(XYZ(spacing+2*shearOffset, 2*spacing+shearOffset, 0)))

# Create a cross-section which twists along the length of the yarn to accommodate the sheared fabric architecture
ellipse = CSectionEllipse(0.18, 0.04)
sectionTwist1 = CYarnSectionInterpPosition()
sectionTwist1.AddSection(0.25, CSectionRotated(ellipse, -twistAngle))
sectionTwist1.AddSection(0.75, CSectionRotated(ellipse, twistAngle))
sectionTwist2 = CYarnSectionInterpPosition()
sectionTwist2.AddSection(0.25, CSectionRotated(ellipse, twistAngle))
sectionTwist2.AddSection(0.75, CSectionRotated(ellipse, -twistAngle))

for Yarn in (Yarns[1], Yarns[3]):
Yarn.AssignSection(sectionTwist1)
for Yarn in (Yarns[0], Yarns[2]):
Yarn.AssignSection(sectionTwist2)

# Loop over all the yarns in the list
for Yarn in Yarns:
# Set the resolution of the surface mesh created
Yarn.SetResolution(20)

# Add repeat vectors to the yarn
Yarn.AddRepeat(XYZ(2*spacing, 2*shearOffset, 0))
Yarn.AddRepeat(XYZ(2*shearOffset, 2*spacing, 0))

# Add the yarn to our textile
Textile.AddYarn(Yarn)

# Create a sheared domain with 6 planes
domain = CDomainPlanes()
d = (2*spacing-2*shearOffset*sin(shearAngle))/sqrt(1+sin(shearAngle)**2)
domain.AddPlane(PLANE(XYZ(1, -sin(shearAngle), 0), 0))
domain.AddPlane(PLANE(XYZ(-1, sin(shearAngle), 0), -d))
domain.AddPlane(PLANE(XYZ(-sin(shearAngle), 1, 0), 0))
domain.AddPlane(PLANE(XYZ(sin(shearAngle), -1, 0), -d))
domain.AddPlane(PLANE(XYZ(0, 0, 1), -height))
domain.AddPlane(PLANE(XYZ(0, 0, -1), -2*height))
Textile.AssignDomain(domain)

# Add the textile with the name "shear"
AddTextile("shear", Textile)

Now when I exporting it through ABAQUS dry fiber file and running it through command windows its not wotking.
Kindly look into it and give your valuable suggestions.
Best Regards
Anurag

[louisepb]

Hi Anurag,

Having run your script I noticed that the surfaces are not generated for the two yarns which are split by the domain. I tried moving the domain as shown below

ShearedDomain.png (163.34 KiB) Viewed 27557 times

If you use the domain editor to move the domain planes as shown then you will move the domain so that it no longer splits the yarns. The surfaces are then generated for all yarns and the Abaqus file then runs. In the short term could you make sure that any textiles that you create have domains which don't cut the yarns along their length. I will take a look at the code and try to work out why this causes a problem with creating the surfaces.

Best regards,
Louise

[anuragdixitiitd]

Many Thanks Louise!! It worked..

[anuragdixitiitd]

Hi Louise,
As the weave in the present case is created via script not by the create weave wizard so it is not possible to edit textile directly from the wizard option. Else if I want to increase the number of yarns and change the present yarn width, there is no option provided. I have to change in my python script. Am I right upto now.
I tried changing in my script for the above inclusions but anyhow it didn't worked. Is there any other method or technique.
Best Regards
Anurag

[louisepb]

Hi Anurag,

You can change your textile in the TexGen GUI. You can't use the wizard edit as it wasn't created using the wizard but you can use all of the options in the Modeller. You can change the yarn cross-sections, add yarns, change the domain etc. See the user guide here: http://texgen.sourceforge.net/index.php ... e#Modeller

Best regards,
Louise

[anuragdixitiitd]

Hi Louise,
Hope you are fine. This time I am trying to generate the script for 2x2 twill weave with sheared domain. As instructed in your previous thread I am trying to model using TexGen GUI and modeler but I am finding it hard to model. Can you tell me any specific procedure to alter the weave pattern in GUI. I mean to say how to have a control on geometry & path.
Regards
Anurag

[louisepb]

Hi Anurag,

The easiest thing to do would probably be to create your weave in the wizard and then to edit it using the modeller. You will then have the basic weave pattern and can move the nodes so that they give you the shear angle you require. You would also need to edit the cross-sections to add any rotations necessary. You would also need to edit the domain as appropriate for your shear angle.

Otherwise you would have to create the yarns from scratch in the modeller, working out the appropriate positions for the nodes.

See the user guide on the website for instructions on using the modeller options in the GUI.

Best regards,
Louise

[anuragdixitiitd]

Hi Louise,
Hope you may be fine!!! Well when I am creating my .inp file from the python script as mentioned in my previous thread for sheared plain weave with sheared domain. I am not getting surfaces created for the yarns in surface definition in dry fiber export.
What I am doing, I am keeping X,Y,Z scale all as 0 and exporting it without compression plate for pure shear, I find in my .inp file that it is not creating surfaces for yarns in surface definition and contacts.

Best Regards
Anurag