No static step after frequency step

Hi all,

I noticed that when step 1 is a frequency step, step 2 cannot be chosen as static step.
For checking the model I sometimes start with setting up BCs within the frequency step in order to run modal analysis to check for correct or no rigid body motions.

After doing that I wanted to set a static analysis as step 2 and just deactivate the frequency step. That’s not possible. Duplicating Frequency step is also not solving the problem because type of the analysis cannot be changed.

Best regards,

That’s right, I haven’t noticed that before. After the frequency step, only these steps can be added:

  • Buckle
  • Heat transfer
  • Uncoupled temperature-displacement
  • Coupled temperature-displacement
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There is a built-in feature that checks if the new step can be of a certain type based on the type of the last existing step. Some combinations of steps namely do not make sense. But that is not true in the case where some steps are disabled. I can easily remove the built-in check but then this decision will have to be made by the user. Any other ideas?

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Perhaps for now you could set this check to allow for two additional combinations which are sometimes useful:

Frequency → Static
Buckle → Static

I could remove the step ordering checker since I am unfamiliar with all possible/allowable combinations and all unallowable combinations.

The check itself seems to be a good idea since it prevents the user from defining wrong step sequences. Something like this also exists in Abaqus. Perhaps adding more combinations (like those 2 listed above) would suffice for now. I’ll try to make a list of possible sequences in the near future.

Having a list of functioning and meaningful combinations would help a lot.

I think I will add a utility to move steps up and down in the list (tree). Some kind of steps manager. For this reason, I will allow all step combinations in the tree and skip checking if some step combinations are meaningful during the step creation. Such a check could be added later, just before the analysis is submitted. Similar to the missing section check.

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That would be very useful. Also, now I should have a bit more time to test various combinations of analysis steps.

Perhaps, a feature to replace a step with a different type could be added. It would be really handy in many cases.

It would be very useful. I have the habit of running a static step before everything just to check the general behavior of the model. And then if I want to convert it to another step type, at the moment I would need to recreate the BC, outputs requests, loads, and so on.

At the moment, I solve this problem by creating a static step first, then I create a new step and deactivate the first static step. In this case, all step items are copied to the newly created step.

I will see how I can include the step replacement feature in it.

To solve the step creation all step combinations will be available in the new version.