Event Simulation

[Pedro_Bidarra]

To test out this feature I prepared the simplest of scenarios, a thin board of acrylic and impacting a ~ 0,5 kg steel sphere at 240 km/h, after waiting a long time to get the results the sphere just goes through the acrylic like it isn't there, no deformation.

[John_Holtz · Accepted solution]

Hi @Pedro_Bidarra

Maybe it is the contact between the sphere and acrylic that is not there. What type of contact did you define between the parts? It should be defined as separation contact.

Here are some tips to reduce the runtime:

1. Make the sphere a rigid body. Because the steel is more rigid than the acrylic, and it is reasonable to assume the stress and strain in the sphere are "0", setting it as a rigid body reduces the computations.
2. The sphere should be located very close to the board. If the sphere is "flying through space", then you are consuming a lot of runtime just to show it moving.
3. Based on the speed and distance, you can estimate a reasonable duration so that you are not spending time watching the ball rebound (or pass through). The duration is set under "Manage > Settings".

[Pedro_Bidarra]

Thank you very much John, indeed I hadn't generated/defined any type of contact between the 50 mm sphere and the the 5 mm thick acrylic sheet.

Now the event simulation worked as you can see in the image below.

[Pedro_Bidarra]

The only thing I see missing from the simulation is that the impact creates a hole and likely acrylic shards also, however any sort of broken material from the broken component is omitted.

[AndrewSears]

@Pedro_Bidarra, if you want to see shards of material then you will need to make a fine mesh in the impact area.  With element deletion turned on, and what appears to be a coarse mesh, the element strain limit was met so they are removed.  Making a dense mesh will delete some elements and show other elements disconnected and flying away.  Be aware of the time to simulate before making a really dense mesh in the impact area.  Adjust the mesh little by little until you visually get the expected results.  

Post a picture when done!

Cheers,

Andy 

[Pedro_Bidarra]

Thank you very much @AndrewSears, I didn't notice about 'element deletion'!

Unfortunately, with a tighter mesh it turned out it actually doesn't break it in the set time frame, and after about 2 and half hours I got the results you can see in the video below. It would be nice that Fusion could give an ETA for simulations like it does for Rendering in the Cloud.

So, I made a new simulation which is still solving, using glass instead of acrylic and a not so tight mesh, I'm sure this one will break in the set time frame.

[Pedro_Bidarra]

Well, it didn't turn out how would expect, the following video was done with glass instead of acrylic and I forgot to turn off element deletion, but we did get shards this time.

Note: It would be fun to combine this simulation with rendering and render these segments with the actual materials

[felipe.tignonsini]

Hi Pedro, how are you going? I hope well...

I'm trying to do something very similar as you did, but I can't set up the contacts correctly... can you explain for me how you did this?

Thanks a lot!