Material Properties Specification

[dyeyanie]

Dear Louise,

I would to verify with you regarding the material properties that is automated set up (lamina properties) in the Texgen. Let say, I make some ammendment to this section since my intention is to use an isotropic properties so, do I need to change anything in the .ori code as well? I'm precisely would like to achieve the elastic properties of the geometry with this specification.

Yanie

[louisepb]

Hi Yanie,

I guess that if you're using isotropic properties for your yarns as well as your matrix then you wouldn't need the information in the .ori file.

Louise

[dyeyanie]

Hi Louise,

Yeah, that's what I understand too. What i mean is the modification made in .inp file and the simulation run will involve the .ori file since it was created once the abaqus voxel option is chosen. So, I'm afraid this ori file will influence the input file that I ammend.

[louisepb]

Hi,

If you remove the references to the .ori file in the .inp file then it won't be loaded.

Louise

[Jensen917]

Hi Louise,

I have a question concerning the young's Modulus and Poisson's Ratio input: TexGen requires the input of Ex, Ey, Ez, vx, vy, and vz of the yarn.(Same for Gxy, Gxz and Gyz of course).
Are these directions coupled with the coordinate system of the yarn (so that x direction is always yarn direction) or are they coupled with the coordinate system of the textile, which I can see in the GUI?

As I used to select all yarns at once and then enter the material data, I thought the directions are coupled with each yarn coordinate system. Otherwise I would have to switch the values for each yarn regarding to its direction in the textile.

Thanks in advance.

[Jensen917]

Hi Louise,

I have another question concerning the shear modulus of the matrix:
With that equation is that calculated and where can i find it? All I can find in the source code is that the shear modulus of the matrix exists, but there is no equation where it is calculated, neither can i set a value for it in texgen.

Thanks!

[louisepb]

Hi,

The value in the source code was a default value which should be replaced with the actual value of the material being used. As you've found, the matrix properties dialog doesn't allow for input of the shear modulus - something which I (and obviously no one else!) had spotted that I'd missed. I'm going on holiday today for a fortnight so I'll put this right as soon as I get back. I'm hoping to do a new release fairly soon after I get back. In the meantime I'm afraid that you'll have to edit your .inp files to add the correct value.

Louise

[Jensen917]

Hi Louise,

I was wondering what is the theory behind the calculations for yarn properties ? If i set the properties of the fibres (e.g. Youngs Modulus, ...) and the matrix, based on which theory are the properites (Youngs Modulus) of the yarns calculated? Is it simply the rule of mixtures?
I have tried to find the calculations in the source code but it does not give me a hint to find out which theory is behind it.

Regards

[louisepb]

Hi,

TexGen outputs the yarn and matrix properties in the Abaqus .inp file (Young's modulus etc). It uses properties (fibre area, density) etc to calculate a volume fraction for the yarn which it outputs in the .eld file. Orientations are output in the .ori file. It is then up to the user to use this information to apply rule of mixtures (or some other method) to calculate the actual yarn properties in the composite.

Best regards,

Louise

[dyeyanie]

Hi Louise,

I have another question here regarding the material properties for dry fibre options. I saw there are no specification to the yarn properties and how could I modify this since I have an anisotropic yarn in my geometry via dry fiber option?

Yanie

[louisepb]

Hi Yanie,

The dry fibre code was written before the option to input full material properties. It doesn't apply these yet (I will add it to my to-do list!). At the moment you will have to edit the .inp file and specify the anisotropic properties yourself.

Louise

[dyeyanie]

HI Louise,

thanks for your information. I forgot to tell you something regarding changing the material specification with python script. I tried to comment them this way (see the code below) but nothing is changed. Do I miss something there?

Code: Select all

#Set section properties
#For Matrix
MatProps = CPropertiesTextile()
MatProps.SetMatrixYoungsModulus(1400, 'MPa')
MatProps.SetMatrixPoissonsRatio(0.3)
MatProps.SetMatrixAlpha(6.5e-006)
# For yarn
YarnProps = CPropertiesYarn()
YarnProps.SetYoungsModulusX(51920, 'MPa' )
YarnProps.SetYoungsModulusY(21970, 'MPa')
YarnProps.SetYoungsModulusZ(21970, 'MPa')
YarnProps.SetShearModulusXY(8856, 'MPa')
YarnProps.SetShearModulusXZ(8856, 'MPa')
YarnProps.SetShearModulusYZ(6250, 'MPa')
YarnProps.SetPoissonsRatioX(0.2489)
YarnProps.SetPoissonsRatioY(0.2489)
YarnProps.SetPoissonsRatioZ(0.2143)
YarnProps.SetAlphaX(-2e-007)
YarnProps.SetAlphaY(3e-006)
YarnProps.SetAlphaZ(3e-006)

Thanks in advance.

Yanie

[louisepb]

Hi Yanie,

You don't appear to be changing the properties in the textile. You need to call CTextle.SetMatrixYoungsModulus etc for the matrix properties. You can either set properties for the yarns for the whole textile (if they're all the same) using CTextile.SetYoungsModulusX etc ( see http://texgen.sourceforge.net/api/class ... xtile.html) or for individual yarns using CYarn.SetYoungsModulusX etc.

Louise

[dyeyanie]

HI Louise,

Many thanks then.

Yanie

[dyeyanie]

Hi Louise,

Sorry for raising this issue again. I'm still can't changed the properties. I wrote ;

Textile = CTextile()
Textile.SetMatrixYoungsModulus(1400, 'MPa')
Textile.SetMatrixPoissonsRatio(0.3)
Textile.SetMatrixAlpha(6.5e-006)
# For yarn
Textile.SetYoungsModulusX(51920, 'MPa')
Textile.SetYoungsModulusY(21970, 'MPa')
Textile.SetYoungsModulusZ(21970, 'MPa')
Textile.SetShearModulusXY(8856, 'MPa')
Textile.SetShearModulusXZ(8856, 'MPa')
Textile.SetShearModulusYZ(6250, 'MPa')
Textile.SetPoissonsRatioX(0.2489)
Textile.SetPoissonsRatioY(0.2489)
Textile.SetPoissonsRatioZ(0.2143)
Textile.SetAlphaX(-2e-007)
Textile.SetAlphaY(3e-006)
Textile.SetAlphaZ(3e-006)

When I compiled them, only Matrix properties are changed and Yarn properties remain the default values.

Yanie