Fusion doesn't indicate what materials are linear and non-linear.

[pblase]

When trying to run a simple event simulation, the pre-check keeps complaining about "one of the materials is not non-linear". However, there is no indication given in the materials menues as to which materials are linear and which non, nor do the messages indicate which material in the simulation is not non-linear! Nor is there any indication as to how to fix any of the other problems encountered. (see attached). 

The entire flow for this simulation utility is very difficult, since there is no clear list of what must be set and no feedback given if you set it wrong, except that something is wrong. You should really have wizards that walk you through the entire process, letting me say that "this is fixed, this is moving, this is steel, this is aluminum" etc, etc so that I can get it right the first time. Then, once I have the hang of it, I can fiddle with the details.

[henderh · Accepted solution]

Hi @pblase,

All of the the nonlinear materials are stored in the nonlinear material library.  In the Study Materials dialog you can filter by library. If you view the material in the material editor you'll see the 'advanced physical properties' button where you can view the values.

In your screenshot, it's a warning not an error to notify you if you intended to use nonlinear materials but didn't choose them.  A warning doesn't prevent the solve.
To help familiarize a user new to Simulation we provide step-by-step tutorials for each study type, and a 'quick setup' series of videos as well (help menu pull-down).

Hope this helps!  Please let us know if you still have questions or suggestions.

[pblase]

Thank you.

It would be very helpful if the Simulation interface could pre-calculate whether a simulation will overrun the maximums before I start it! It's rather annoying to have a simulation run for several hours and then be told that it's too big!

[henderh]

Great point!  As you've discovered, we do set a limit on how long we'll allow a solve to compute before calling it quits for Event Simulation.
We're able to use a function (I believe it's called the Courant stability limit) that is a good estimate if the solve will converge or not within 20 hours of computing.

Unfortunately, we don't include this data check in the pre-check command that you can run before solving. Instead, we perform the check as one of the first things after sending the job to the cloud. If we've determined the solve won't finish, we'll return a message stating so.
We may consider lifting the limit after Event Sim has graduated from preview.

If you have a setup that runs for hours before stating it will exceed the maximum timeout period, if possible please share it with us so we can take a closer look.

Best regards,

[pblase]

It's a simple ball and plate model:

https://a360.co/35qUJr2

(It's running now, so it won't let me download it.)

[henderh]

I see what may be the issue with the long solve time.

With Event Sim, since things can happen almost instantaneously, it's best to place the bodies just before an event would occur.  Instead of setting up a "long"compute time of 0.05 seconds, try using 0.005 seconds but move the ball much, much closer to the plate to where it's almost touching.
I believe the explicit solver will take as long to compute a step when 'nothing exciting is happening' as it does when bodies are getting torn apart.
There is definitely room for improving this, but for now it's considered as-designed.

Hope this helps!

[henderh]

I've been waiting over ten minutes after sending the solve and still do not see a notification that the solve will exceed 20 hours.  I've logged the issue as ID-58910 and forwarded it on to develop for further investigation.

We appreciate you bringing this to our attention, and apologize for the inconvenience this is causing. Please let us know if you have additional questions, comments or suggestions.

Best regards,

[henderh]

I've logged an issue (ID-60186) to set the active material library selector to the nonlinear material library by default for Nonlinear and Event Sim study types instead of 'all libraries'.

I was mistaken and our solver timeout / exceeded is set for 12 hours, not 20 for event simulation. My apologies for the false info.

Best regards,