This is the second post in a series where I will show you how my team and I at AQUILO, a student rocket team based in the Netherlands, use Dassault Systems' Composites design app in our manufacturing process. In my previous post, we discussed how we prepared the design of the nose cone mould using the Generative Wireframe & Surface app from Dassault Systems. Today, we will discuss how to add plies to corresponding grids and how to visualise and change the stacking to our needs.
To start, we will generate groups of plies based on the previously created grids. This will allow us to reinforce or create a ply that can be handled more carefully. For instance, we need to place a ply from the sleeve of the nose cone to the tip as a first layer. However, layering the entire section at once will result in lousy control during the layering process. Therefore, we divide this into smaller pieces. With the grids created, we can now define the layer thickness at each grid to create reinforcements where needed. As you can see in the attached photo 1, not every grid has the same amount of plies. For example, grids C4 and C8 have more plies than grids C1 and C5.
In the case of the tip, we would like to have one ply that can be layered in advance to create a perfect tip shape. Therefore, we choose a 90/0 ply selection, where 90 and 0 describe the orientation in degrees at which the fibres are located. This is important to consider when using unidirectional laminate (fibres facing in one direction). In our case, we are using a bi-directional laminate (two directions 0 and 90). So, this is not useful for us, but I have shown it to demonstrate the wide range of possibilities from the app.
Once we've added the necessary number of plies to the appropriate grids, we can observe how the app arranges the plies for us using ramping. This process entails adding a specific material to each ply to overlap the previous ply. In the second attached photo, you can see the resulting layering, with the first ply being a 0-degree ply that passes through the tip, main body, sleeve build-up, and sleeve. This is not ideal since it provides less control and reduces the chances of getting the tip perfectly. Therefore, we need to change the layering order so that the first ply we lay down is from the tip grid section. The app has considered this design modification, making it easy for users to rearrange the plies' order. The third attached photo shows my result, with the nose cone grid section ply as the initial.
To complete the layering order of the plies, you can create a cross-sectional view of the plies stacked on top of each other using the app. You can preview this view in pictures four, five, and six. Picture number five shows a zoomed-in cross-sectional view of the sleeve ramp-up, where you can see the ramping that was defined beforehand. In picture six, you can see that the first ply at the nose cone grid section is separate. This cross-sectional view also serves as a validation tool to ensure you are satisfied with the layering result.
This is the end of this week's post about using the composite design app to prepare for the manufacturing of the nose cone. I hope you enjoyed it, and next week, I will go over how to verify the possibility of layering the cutout plies and flattening them using the composite design app and the composites manufacturing preparation app.
Edu Composite Design
