why -45 degree can't generate in texgen?

[heidi sofian]

Hai...i just want to ask about texgen?.. why i can't generate -45 degree of stacking sequence?...this is because when i enter my -45 degree of stacking sequence in my 24 layer of fiber in texgen, this apps can't generate while the others degree of stacking sequence can generate...why? can i know?

[louisepb]

Hi Heidi,

Could you be more specific about what you're trying to do and where you encountered a problem please. Which TexGen options did you use? Is it that you tried to do something and TexGen crashed or that the option isn't available to do what you want to do?

Best wishes,
Louise

[heidi sofian]

hi,
I'm doing the ballistic impact response of sheared Malaysian-woven composite, so the Malaysian-woven that i used was 24 layer, and have different stacking sequence for every layer.
The TexGen option that i used was laminated textiles, the degree of stacking sequence angle that i choose are 0,+45,-45 and 90 degrees. But, while i'm using this -45 degree of stacking sequence angle, the apps can't generate. May i know why?

[louisepb]

Hello,

I'm afraid that I'm still unclear as to the exact steps you're taking in TexGen which may be causing a problem.

Are you creating textiles, using the Rotate Textile option to rotate them and then using the Create Layered option to create the stacking sequence?

I have tried this procedure with a plain weave textile and it works fine with both 45 and -45 degrees.

Could you provide information on the exact steps that you're taking and, if possible, the textile file that you're trying to rotate.

Thanks,
Louise

[heidi sofian]

Hello sir,
I'm sorry for making you confused on my detailed.

Yes, i'm creating a textile but i'm not using the Rotate Textile to rotate them because i thought just fill the stacking sequence angle into the sheared textile. Is it i have to put the stacking sequence angle at Rotate Textile and also sheared textile? Or just fill the stacking sequence angle at the Rotate Textile?

For the plain weave that you said before, yes, the textile at -45 degree with one layer were work fine also with me , but when i layered it into 24 layered, the textile can't generate.But, when i ignored the layer that contain -45 degree the textile can work fine with 24 layered(0,45,90 degrees). May i know why?

And also, is it Rotate Textile and sheared textile is the same thing?

Thank you.

[louisepb]

Hi Heidi,

Shearing and rotating aren't the same thing. If you shear a textile then the angle between the warp and weft yarns will be changed by the shear angle. It's unlikely that a shear angle of 45 would be possible as the yarns would lock and the textile would tend to wrinkle.

Rotating the textile simply rotates the whole textile by the given angle, leaving the warp and weft yarns at their original angles relative to each other. I assume that this is what you would want to be doing for a layered textile.

Please could you send me details of the exact textile that you are using, the steps that you have taken to rotate and how you have created the layered textile. When I try with just a default plain weave and and angles of 0, 45 and -45 with 24 layers it works fine. There must be something happening in your particular configuration so I would need exact details in order to be able to replicate the error and find out whether there's a bug that needs to be fixed.

Hope that helps,
Louise
PS. Louise is a woman's name

[htl320]

Hello All,

I also have a problem generating textiles with layers including a +-45° orientation and another orientation (i.e. 0°, 90°), as TexGen stops responding. I have also noticed that while creating a simple 0°/90° textile the resulting layered textile is incorrect. Unfortunately, I cannot upload a PDF due to its size but here are the slides in image form (I can provide the dup_rot.py script, if necessary) :

1.PNG (123.2 KiB) Viewed 10862 times

2.PNG (61.14 KiB) Viewed 10862 times

3.PNG (101.95 KiB) Viewed 10862 times

I haven't tried to create very complicated textiles yet, but in the future I would hope to be able to create a textile with a configuration such as 0°/-45°/90°/+45°/90°/0°.

My current procedure is the following:
- create weave
- duplicate weave by creating layered textile with weave
- rotate the layered textile
- create a new layered textile with the original weave and the rotated layered textile

Am I doing something wrong in the way I go about setting up the textile? I need to be confident that the final configuration of the textile is what it is supposed to be.

[louisepb]

Hello,

Sorry for the delayed reply, I have been off work for the Easter break.

When a textile is rotated it will, by default, rotate about (0,0) and the yarn nodes defined will change accordingly. If you do not rotate the domain then the section of the textile that you are displaying (assuming that you're clipping to the domain) will no longer necessarily correspond to the unit cell. In the first of the diagrams you have shown you are combining two textiles with different domains. The way that TexGen is programmed it takes the maximum/minimum boundaries of the domains and uses those as the new domain. It has been done this way so that if, for example, a plain weave spanning two yarns and a twill weave spanning 4 yarns are combined the resulting domain will cover the whole of the larger textile.

Once textiles have been rotated and are combined with different sized or oriented domains there is no guarantee that the resulting textile will be periodic. It is up to you to define what domain you actually want to use for your resulting textile and how you will apply boundary conditions if this is not periodic.

Sorry this isn't a definitive solution but there was no way of programming TexGen to cover all possibilities. At this point it is up to the user to define exactly how they want to use the model generated.

Hope that makes sense.
Best wishes,
Louise