Learning Forum

[Sushil Sharma]

I am trying to create a composite layup model of a wind turbine blade. How can I vary the composite thickness (linearly) along the length of the blade? I used the "selection rule" tool to subdivide the blade to model different ply numbers in a different section( it create constant thickness in each subsection which is not linearly variying). Is there any alternative way to perform the such task?

Secondly, when creating sandwich elements using the "section rule." how will they be stacked up towards the hub I want the core material always modeled in the middle between the fiber stacked up (in my case the sandwich element stacked up one behind the other).

Third, While using "section rule" to vary the composite thickness how can we deal about the abrupt variation in thickness in one section. Does it effect in fatigue analysis while there will be notch at every subdivided plane.

Thank you

 

[Reno Genest]

Hello Sushil,

If you have different number of plies along the length of the blade, then the thickness will not be constant. You should get a linearly changing thickness similar to the model I showed in another post:

https://forum.ansys.com/forums/topic/acp-pre-peg-modeling/#post-248847

Make sure you don't disable the ply drop-offs. Don't check the boxes in the image above. 

Make sure the number of plies is different along the length of the blade and that the thickness is varying:

 

If the thickness is constant, then something is wrong in your model and layup. 

If you follow the manufacturing process of the blade in ACP, you should be okay. In real life, which layer is put in the mold first? Then, this first layer should be applied in ACP. Which layer is put in the mold second? Do the same in ACP. 

Let me know how it goes.

Reno.

 

 

[Reno Genest]

Hello Sushil,

If you have access to the Ansys Learning Hub (ALH), you will find the ACP training course here:

https://jam8.sapjam.com/groups/YHNivy2FbzTCwBmZhqlMGS/overview_page/X59hQ2TTw5kCamrfUyAeA6

Or you can have a look at the following free course:

https://courses.ansys.com/index.php/courses/formula-sae-composite-monocoque-chassis-analysis/

 

Reno.

[Reno Genest]

Hello Sushil,

Can you post a screenshot showing the problem of the sandwich elements being stacked up one behind the other? I can't picture the problem.

 

Thank you.

 

Reno.

[Reno Genest]

Hello Sushil,

You want to avoid abrupt change in thickness in your composite layup; this will lead to stress risers which are not good for fatigue life. Make sure you have surfaces in your finished model as is the case in the real wind turbine blade. Your model should be like the real turbine blade. If you do the layup properly, you should end up with a linearly varying thicknesses due to ply drop-offs; you should not have abrupt changes in thickness. If the linearly varying thickness is not good enough for you, you can achieve a smoother thickness change by using a CAD surface to extrude the composite layup into a solid model (I assume you want to create the solid model):

 

You will find more information in the ACP help:

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v231/en/acp_ug/acp_solid-model.html

 

Let me know how it goes.

 

Reno.