Save/Restore with ASDShell in OpenSeesMP – Multiple Time Histories?

[n.dgn]

Hello everyone,

I am trying to run multiple independent time history analyses in OpenSees within a single run.

My goal is:
Apply a static gravity analysis first (as preloading / initial condition).
Then run several different earthquake records (time history analyses) one by one.
Each earthquake analysis must start from the same gravity-loaded state.
There should be no interaction between earthquakes (no accumulated damage from previous records).

So I want the workflow to be something like:
Gravity analysis
save the gravity state
For each earthquake record:
- restore gravity state
- run transient analysis
- store results

For this reason, I tried using:

Code: Select all

database File ...
save 1
restore 1

However, my model includes ASDShell elements (ASDShlLQ4 / ASDShell type elements), and when I try to use restore, the analysis crashes (especially in OpenSeesMP parallel runs). I get errors such as:

ASDShlLQ4::recvSelf() failed
FileDatastore::recvVector() failed
domain failed to recvSelf
or MPI crashes like BAD TERMINATION of one of your application processes

So it seems that save/restore does not work properly when ASDShell elements are included (maybe sendSelf/recvSelf is not fully implemented).
My questions:
Has anyone experienced save/restore problems with ASDShell elements before?
Is there any known fix or workaround (different database type, different OpenSees build, etc.)?
If save/restore cannot be used reliably, what is the recommended way to run multiple independent time history analyses?

I know that I can use:

Code: Select all

remove loadPattern ...
wipeAnalysis
setTime 0.0

but as far as I understand, removing load patterns does not reset material/element state, so damage from previous earthquakes would still remain.
So how do you usually ensure that each transient analysis starts from the same initial gravity state without accumulating damage?

Any advice would be appreciated.

Thank you!

[STKO Team]

The save/restore should work, but we didn't test it recently, so maybe, due to some late changes, it may not work.

Anyway, using the database for what you want to do is probably overkill.

You have another option (the reset command).

Code: Select all

foreach GroundMotion {
	run gravity analysis
	set GroundMotion
	run time history
	setTime 0.0
	reset
}

The reset command brings back the node and element state to the beginning, as if not analysis has been performed before. The only drawback is that the gravity analysis is performed multiple times, but that's not the expensive part