FEA Simulation of a Composites Wind Turbine

In this video, we are going to look at the design of a thin composite structure based on the example of a vertical wind turbine. We'll take a look at how we go from geometric models to deformations when loads are applied.

And we'll take a look also at how we can analyze first-ply failure of the composite model. And we'll go up one step showing you how to easily perform a design change on the model.

The starting point of our model is actually defining the geometry itself and defining the composites layup on this geometry. Here is the geometry of the wind turbine we'll be working on.

And this geometry has been made parametric so as to change the dimension of the lateral blades that we see on the model. We of course need material models and in this case, we'll use an epoxy carbon whose orthotropic characteristics have been defined.

The next thing we need to do is to create a mesh on the model and actually we'll create also a number of name selections just to identify some of the parts of the model like edges or faces. Here we see a picture of the mesh.

And we have the folder with name selection at the bottom that shows that we have defined a number of entities that we'll use to define orientations or simply ply locations. As a next step, we can start defining our composite model. We see here the import of the epoxy carbon that we defined before.

And we're creating a fabric which is based on this material and a thickness of 1. The next step is defining a stackup made of 4 layers of this fabric with different angles. So we'll start with an angle of 0, an angle of 45 degrees, minus 45, an angle of 45 degrees.

And finally an angle of 0. And an angle of 90 degrees. And at the same time, we can already analyze the model locally and see how the stacks are laid over each other. And also the polar properties of the materials like you see here on the right-hand side.

Then we will define the material orientation. In this case, we use a cylindrical coordinate system so as to define the orientations on the shaft following the tangential direction of the cylinder that defines the shaft.

So the thing we do here is selecting the shaft, choosing the coordinate system that will be used for the orientation. And when we draw the orientation, we realize that we indeed follow the second tangential direction around the cylinder.

And at this stage, we are ready now to define the ply groups on the shaft itself. So we've defined the orientation and now we are going to choose our shaft again and define the stackup we are going to use. Remember that was our 4 layer stack that we defined earlier in the process.

And we can here define even the number of layers we want. So in this case, we have 2 layers. And if we look at the modeling plys, we see that we have those 2 layers of 4 plys each applied with each their angles. Like the 0 angle, the minus 45, the 45 and the 90-degree angle.

Now that we have defined the plys on the shaft, we can define the plys on the other parts as well. In the case of the vertical parts, we are going to use the blades. We are going to use the blade edges we had defined at the beginning of our process as guides to define the direction.

The 0 orientation of our material. So that's what we are doing here. Using not the coordinate system but the edges themselves. So we see the orientation that flows along the edges of the vertical parts. And obviously, we can also create plys on it. Just like we did before using the same fabric.

Maybe changing the number of layers depending on what we want to achieve. For each of the plys. And for each of the sections. So in the part we've defined, we can also create section cuts that will show us how the plys are laid in a given section.

Including the drop-offs that you will notice on this part where you see that we have a different number of plys. Either at the trailing edge or in the center of this blade.

Now that we have defined our composites, the next step is really to perform the structural analysis based on a set of boundary conditions. And review the first-ply failure data that we'll see in our post-processing tool. Here we just put a support at the bottom of the shaft.

And we put a rotational velocity to mimic the motion of the blade. And the next thing we will be able to do once the model has been solved is really review the results.

In this case, the data of the composites model has been automatically transferred from our composites definition into the simulation module that we see here. Which is in this case ANSYS Mechanical. And once we have reviewed the deformations and maybe the stresses.

We can move on to looking at the specifics of composites especially the failure. So we look here at first-ply failure and the first criteria we display is a global one indicating where the critical areas are. In this case, we don't have any red regions. Showing that we have designs that won't fail.

However, we have some orange regions and we may want to know exactly what happens in those regions. And in this case, it's fairly easy to plot the failure criteria themselves. And look at which are the failures. Which ply is failing for which criteria.

So which criteria is really the most significant or the most critical here. And that's what we see here through the overlay of a text plot on each of the elements. So for each element, we identify the failure criteria. The ply it happens on as well as the load case if we have multiple load cases.

We've seen this design is safe because the inverse reserve factor was not exceeding the value of one. And we made it for a blade width of 100. So we can see that the blade width is 120. But what happens if the blade width was 130? What would this change to my model?

And to know that it's here very easy to change the value of the blade width to let's say 130. And just update the project to check new results. And here we have a full update of the model including the simulation model including the solution.

And we can review the results and realize that in this case, indeed changing to 130. Led to a few more critical areas that we see here from our parameter value exceeding a value of one with 1. 07. So you see here that it's very very easy to create a design change on the model.

Let's summarize what we've seen. So we started from a geometric model that was parametric. Created the composites layer upon it. Looked at deformations on the model. Before we investigated the first-ply failure of the model through global factors or local factors.

And we were able to easily create design changes by changing dimension and looking at the influence on our design. If you want to learn more about our solutions, visit us at ensys.com in the products. Thank you. Thank you.