How to specify the derivative when defining yarn path?

[bluezoe]

Hello,

When I trying to build a RVE of tube, the derivative of start and end point of the yarn path is no more equal.
I can define the derivative value when using the CubicSpline function in scipy.How should I do in TexGen when applying the function

Code: Select all

yarn.AssignInterpolation(CInterpolationCubic())

.

And there is another problem, how can I using the function yarn.AddRepeat( XYZ(xr,yr, zr) ) to repeat the curve.

Sorry for bothering you and thanks for your previous kind reply.

zoe

[louisepb]

Hi Zoe,

There is information about specifying repeats here: http://texgen.sourceforge.net/index.php ... de#Repeats
If you make sure that you use periodic interpolation and that the positions of your nodes correspond at either end of the repeat then the tangents should align to make the yarns continuous.

Hope that helps,
Louise

[bluezoe]

Hi,
Thanks for your reply. Maybe I am not making myself clear.

When I was trying to design a tube RVE where dark line is warp cross-section while the yellow line is weft using periodic CubicSpline interpolation(this can be made in Texgen).
The green line is also using CubicSpline interpolation but the derivative is no more equal in the two ends(this is using scipy interpolation function).

I was confused because in Texgen the CInterpolationCubic() function only includes three bool input parameters. How can I define the ends derivative to obtain the green line in Texgen?

And I read the repeat function, it seems can only offset the yarn and can't rotate the whole yarn path.

[louisepb]

Hi Zoe,

Apologies for the slowe reply. The interpolation functions in TexGen use the nodes and if the interpolation is periodic they use a node with the repeat added to force the repeating interpolation. At the moment the only repeat vectors which can be applied are translational. There is nothing to allow a repeat in the form of a rotation. One of our researchers has been creating models of braided textiles but created a model which was larger than the unit cell, effectively creating the repeat manually, and then created a domain which was the size of the unit cell.

I hope that is of some help although I don't think it completely answers your question.
Best wishes,
Louise