Fusion 360 Non-linear simulaton

[snaMQ3JD]

Hi!

How can i view intermediate output in a Fusion 360 Non-linear simulaton if the analysis failes?

e.g. Inventor Nastran allows to tick Intermediate Output = on which enables me to view all the increments up to the failure load. Is this not possible in Fusion 360?

Also, where can i define a custom number of bisections for each increment?

Regards

[John_Holtz · Accepted solution]

Hi @snaMQ3JD 

Here are the answers to your two questions:

1. It is not possible to view the intermediate results or the partial results of a nonlinear simulation in Fusion. The analysis needs to complete 100% before any results are returned.*
2. The number of bisections permitted is an input value that is not available to Fusion users.

* Except, the one "result" that is available when the analysis fails is the output file. (Of course, the output file is also available when the analysis is successful.) Right-click on Results in the browser and choose "Solver Data". When the dialog appears, change the option from "Solver Data" to "Solver Output". At a minimum, you can find out how many increments it completed and if there were other warnings or errors that may indicate what caused the problem. For example,

• If the analysis fails to converge on the first step, it is often due to a piece of the model being close to unstable. Confirm that everything is restricted from moving by constraint or contact. If there is a piece that is questionable, add a constraint to see if that helps get to the first step.
• If the load increment gets to the point where the model may start yielding, check the material properties. I am not sure where Fusion gets the stress-strain curve, but I often see the stress-strain curve is essentially the same slope as the elastic modulus for a considerable range of stress. I suspect this is hard for the solver to converge and always recommend changing the stress-strain curve.

John

[shekar_sub · Accepted solution]

Hi  snaMQ3JD,

 ,> How can i view intermediate output in a Fusion 360 Non-linear simulaton if the analysis failes?

If the Non-linear analysis fails there are no results to view.

> to view all the increments up to the failure load. Is this not possible in Fusion 360?

If the solve succeeds then one can look at the results at different steps. I have attached an image from the Simulation Samples-> Accuracy Verification Examples -> NonlinearStatic_AVE-01.f3d.

 

>Also, where can i define a custom number of bisections for each increment?

That is not supported. However one can specify the number of steps for the non-linear Simulation under Right Mouse Button on the Study in the browser and Settings.

The other limitations of a Non-Linear static stress study are listed here:https://help.autodesk.com/view/fusion360/ENU/?guid=SIM-NONLIN-STATIC-STRESS are listed here.

If you want one of us to take a look at the model please attach it. We will checkout why it is failing.

Best regards

shekar

[jeremy_camper]

Hope it's OK I message you

1. I've done a few static simulations but this is my first nonlinear... what faces should I select in this example picture? I guess I don't understand non linear so far?

2. Can you save that animation to a video file?

[shekar_sub]

Hijeremy_camper,

For your #1, the dataset is available in Home->Samples->Simulation Samples->Accuracy Verification Examples->NonlinearStatic_AVE-01.f3d. You can open this dataset and take a look at how it is setup including which faces are selected. In Simulation workspace you can edit the load Force1 and/or constraint Fixed1. 

For #2 I do not see an option to save the animation in this page to a video file. https://help.autodesk.com/view/fusion360/ENU/?guid=SIM-NLSS-HOW-TO-OVERVIEW

Best regards

shekar