yarn/matrix properties

[loyal979]

Hi,

I just need some clarifications on the properties of the yarn and matrix. so to assign the same properties to all the yarn, should assign the properties to the yarn individually or is there a way to assign them in one step?
and where can I obtain the properties like the yarn linear density, fiber density, total fiber area, fiber per yarn, fiber diameter...etc. Also, what does Alpha represent ?

Thanks

Matt

[louisepb]

Hi Matt,
If you select all of the yarns then you can assign all of the properties at the same time. You can either select all yarns by using shift+click to select each yarn in the main window or, probably easier, select the first yarn in the outliner window and then shift+click on the final yarn in the list which will select all yarns.

You should be able to get yarn properties from the fibre data sheet. Note that you don't necessarily need all of the fibre dimension properties. For calculating the volume fraction TexGen will use either the total fibre area or the linear density + fibre density or the fibre diameter + number of fibres.

Alpha is the coefficient of thermal expansion.

Hope that helps,
Louise

[loyal979]

Hi Louise,

Thank you. just to clarify this, how to get the total fiber area and fiber diameter? Do I have to calculate them or I can obtain them from Texgen?

Also, if I export my model as Tetgen mesh or volume mesh and assign the properties in Texgen, and apply the boundary conditions and loads to my model in Abaqus , will I be able to distinguish the results for the tows and the matrix?


Thanks

Matt

[louisepb]

Hi Matt,

You should be able to get the total fibre area and fibre diameter from data sheets. As I said, you don't necessarily need both of these values.

If you export the models from TexGen then the properties should be set up for both the yarns and matrix. In both the tetgen and volume mesh export to an .inp file then there are boundary conditions and loads already set up in the file. Obviously you can change these if you want to but bear in mind that if you load the file into CAE then the orientation and volume fraction information won't be imported. You need to run from the command line in order to use these.

Best regards,
Louise

[loyal979]

Hi Louise,

when you say that in both the tetgen and volume mesh export to an .inp file then there are boundary conditions and loads already set up in the file. Are these BCs and loads are default? I tried to do full analysis on a simple 2D model but gave me no results. Everything is zero. But when I try to apply BCs and loads in Abaqus and try to run the job in Abaqus, it gives me error and I have no idea why. Please advise me on that.. Basically, what I want to do is that apply a load and boundary conditions to my model in Abaqus and do finite element analysis.

I did run my model through command line to do Abaqus job but I still get error. I have attached my model and a picture to show messege.


Thanks

model.png (29.77 KiB) Viewed 129220 times

error.png (255.59 KiB) Viewed 129220 times

[louisepb]

Hi Matt,

If you use the volume mesh export and select periodic and the boundary conditions in the dialog then you will have an input file which you can use as described in the last two sections here: http://texgen.sourceforge.net/index.php ... and_Abaqus

Apologies, I had forgotten that the tetgen export only adds the nodes and elements to the input file. You would need to add the other information yourself.

Best regards,
Louise

[ebarbero]

I know the overall fibre volume fraction of the composite obtained from matrix acid digestion test, or burn-out test, and the density of the fibre.
I do not know the fibre diameter, number of fibres per tow, total fibre area, nor areal weight [kg/m^2].
All I can do is take the weight of a composite specimen, burn the matrix away and take the weight of the dry fabric (the matrix is gone). That gives me the fiber mass fraction.
The fiber is glass, of which I know the density. The matrix is epoxy, of which I know the density. With that I can convert mass fraction to volume fraction. What fibre volume fraction is this? none that Texgen uses, right?

Anyway, how can I calculate yarn properties, such as total fibre area, to enter in the Texgen wizard?

Is total fibre area the area of one tow or yarn? -- of which I have 4 in the domain.

Is Domain Volume Fraction = yarn volume / domain volume ?

Is Yarn Fibre Volume Fraction = fibre volume / yarn volume ?

[Zeynep Nur Akyazıcı]

Hi,

I design 3D orthgonal weave. I entered the following data:
Weft data:
Yarns:2
Layers:2
Yarn spacing:0.003
Yarn width:0.0024
Yarn height:0.0003
Power ellipse section:0.6
Warp data:
Total number of yarns:2
Ratio:1:1
Layers:2
Yarn spacing:0.003
Yarn width:0.0024
Yarn height:0.0003
Power ellipse section:0.6
Binder data:
Yarn spacing:0.0015
Yarn width:0.0012
Yarn height:0.00015
I thought linear density and fiber density would be sufficient for volume fraction. And, linear density:0.00081 fiber density:1760 for warp and weft, linear density:0.000067 fiber density:1780 for binder. If ı entered 1780 for binder, it gives Binder yarn initial volume fraction exceeds max Vf Yarn: 2. So, ı change the linear density for binder. But why is it giving this warning?
Then, ı made linear density :2620 for binder. But domain volume fraction:345375.19. Why is it such a large value? Do I need to enter more data for 3D orthogonal yarn?

Best,
Zeynep

[louisepb]

Hi Zeynep,

It is difficult to make sense of your data without any units. Providing the linear density and fibre density of the yarns should give enough information to calculate volume fraction. Maybe make sure that the units you have used in the TexGen properties dialog are consistent?

Are you sure that you have selected appropriate cross section dimensions? TexGen will assume yarn dimensions are in mm.

Hope that helps,
Louise

[Zeynep Nur Akyazıcı]

Hi Louise,

I wrote to yarn properties as meter. When I wrote it as mm, the problem was solved. Thank you.

Best
Zeynep