Spectating layup processes: The Simulation

Simulating manufacturing processes enhances productivity by extending the tool chain by offline capabilities that otherwise would require a lot of experimentation and testing on the live machine system. By giving the CAM programmer the possibility to verify that the machine is moving correctly, that the laminate is placed in the right position, that the axes are within their limits and that no collisions are detected, the actual time to check for these on the real system is greatly reduced. This however requires a perfect match between the real system and the digital twin.

The following questions may be answered confidently, when using a simulation to verify the laminate layup program offline:

Is the machine moving as intended? Is the movement direction correct, or is it inverted?

• This is especially important when optimizing the manufacturing time. See this example: when the layup direction is from top to bottom, the tool needs to move to the top after every course. When it is alternating its layup direction, the tool needs to rotate by 180° and can then lay down material on the “backward” movement.

Figure 1: A ply in which every course is to be laid from top to bottom. The diagonal yellow lines are the movement paths towards the start of the next course.

Figure 2: A ply in which every second course is to be laid from top to bottom. Therefore, the movement paths towards the next courses start are very short

Is the rotating table rotating clockwise or counterclockwise?

• When using a rotating layup table for laminate manufacturing, the positive rotational direction is usually defined by a clockwise rotation of the table around it’s z-axis. To verify that the simulation is equivalent to the exported program and to the real system, the simulation can be spectated to verify. This is a common error, that’s fixed easily and on which no time needs be wasted.

Are any axis limits reached? Which and when?

• By simulation the manufacturing environment and the layup system, checking against the individual axis limits (especially when using robot systems) becomes very easy. In our experience, it is one of the most important parts of offline CAM process simulations, since it can alleviate a lot of time-draining troubleshooting on the real machine.

Does the machine collide with anything or even itself?

• If there is any external geometry placed in the manufacturing area (such as another mold) it is of utmost importance to verify that the layup head is not colliding as not to destroy this sophisticated and delicate component. When working with robot systems that are packed with additional components (such as material spools, power cables etc.) there may also be additional collision geometry that needs to be avoided. Simulating the manufacturing process with the matching CAD models yields accurate results and successfully prevents any danger to the robot, machine, and environment.

Here are some video snippets from the CAESA® Composites TapeStation in a side-to-side comparison to the real manufacturing machines. You can find the full videos, showcasing a well implemented simulation that can reproduce the real system 1:1 on our YouTube channel: Opti AFP and IFW Kiteboard.

In next week’s article we will explain the functionality and necessity of a post processor. This piece of software transfers the data from the CAM system to the manufacturing system. With next week’s article we will then slowly change subjects to a special project and manufacturing system that we want to showcase. We will take about OptiTape, a project where new functionalities have been explored and realized: multiple materials of different widths, non-perpendicular cutting angles and welding during the layup process.

Feel free to comment or message us at any point. We appreciate any constructive feedback!

Until then, stay safe and stay tuned.