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#1 2019-12-03 15:45:36

corra
Member
Registered: 2008-06-03
Posts: 120

Push-over analysis with softening

Dear All,

I am trying to perform a nonlinear analysis with proportional loading on my structure at displacement control. The idea is to capture the softening part of the global behaviour. I created a simple test with a prism (with ENDO_ORTH_BETON material) subjected to compression and controlling the vertical displacement of one of the top nodes. My analysis goes fairly well until I reach the maximum force, but I cannot get the softening branch. My opinion is that I am missing some command under PILOTAGE keyword to allow the load multiplier to decrease (with increasing displacement, of course). Can anyone help me please?

I know that in this specific case I could easily apply the load as imposed displacement, but in general it is not always possible. This is only a simplified model to understand PILOTAGE command (which I suppose is what I am looking for).

Best regards,

Corrado


Attachments:
test.zip, Size: 18.76 KiB, Downloads: 8

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#2 2019-12-04 12:38:46

GPSalachs
Member
Registered: 2018-03-10
Posts: 139

Re: Push-over analysis with softening

Hello i think you should into PILOTAGE. A thread that has a discussion on STAT_NON_LINE and PILOTAGE is found here: /forum2/viewtopic.php?id=14767

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#3 2019-12-05 09:46:34

corra
Member
Registered: 2008-06-03
Posts: 120

Re: Push-over analysis with softening

Dear GPSalachs,

Thank you for your contribution. I am already using PILOTAGE, but I cannot get the descending branch of the curve. In the post you mentioned, which I had already seen, they talk of either:
- applying a load with a certain loading ramp, or
- applying a displacement.
which is not what I want achieve. In my case I have a proportional loading which can increase or decrease depending on a control node, whose displacement always increases according to the ramp described in DEFI_LIST_INST command.

I hope someone can help me with this.
Best regards,

Corrado

Last edited by corra (2019-12-05 10:53:27)

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