How does NODYNRSP do its thing?

Does anyone know how the NODYNRSP option of the RESVEC command do what it does?

I haven't been able to find any documentation on this detail.

My (wild) guess is a low pass frequency dependent damping is applied to the modes associated with residual vectors to allow them to be suppressed at high frequency but allowed to responded at low frequencies...

Second question on this topic (which is likely related to the first) is why the NODYNRSP option embedded into the RESVEC call. It seems like it could/should be a separate option on top of the RESVEC command.

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0 anthony.carlson over 5 years ago

Don,

Ok it is making some more sense here.

A recap of what you said: any residual vectors generated in an upstream superelement, with NODYNRSP enabled, have no bearing on how assembly run residual vectors will dynamically respond or not. This is now clear to me, thanks for that.

To test your idea from your original comment I did the following:

A) I generated a superelement with resvec turned off.

B) In two separate SOL112 assembly runs using only this superelement (no residual structure) I kept everything the same except for:

Run 1: RESVEC,NODYNRSP = YES

Run 2: RESVEC,DYNRSP = YES

I don't know how to directly dump the modal mass matrices but I did add in MEFFMASS(ALL)=YES hoping to see something different between the two runs

Confirmed in both that residual vectors were generated in both runs (total of 8).

When I looked at the generated .f06 files with a diff tool, they were identical except for the case control echo.

I am not sure I am fully testing your theory. Could you let me know how to dump the modal mass matrices directly?

I can share files if needed.
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0 anthony.carlson over 5 years ago

Don,

Ok it is making some more sense here.

A recap of what you said: any residual vectors generated in an upstream superelement, with NODYNRSP enabled, have no bearing on how assembly run residual vectors will dynamically respond or not. This is now clear to me, thanks for that.

To test your idea from your original comment I did the following:

A) I generated a superelement with resvec turned off.

B) In two separate SOL112 assembly runs using only this superelement (no residual structure) I kept everything the same except for:

Run 1: RESVEC,NODYNRSP = YES

Run 2: RESVEC,DYNRSP = YES

I don't know how to directly dump the modal mass matrices but I did add in MEFFMASS(ALL)=YES hoping to see something different between the two runs

Confirmed in both that residual vectors were generated in both runs (total of 8).

When I looked at the generated .f06 files with a diff tool, they were identical except for the case control echo.

I am not sure I am fully testing your theory. Could you let me know how to dump the modal mass matrices directly?

I can share files if needed.
Cancel
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