#1 2022-03-27 19:35:25

EnKiNekiDela

Member

From: Slovenija

Registered: 2021-11-07

Posts: 24

[SOLVED] DYNA_NON_LINE working with absolute/relative displacements

Hello everyone,

I am recently working on non-linear example of a seismic transient. R4.05.01 is discussing  equations of movement in absolute/relative reference marks.
My intent was to use absolute displacement time history as input (load_uxyz from Stage_2.comm in attachement).
Results are extracted from DEPL, ACCE fields (POST_RELEVE_T).
Now I am a bit lost on how to make sure inputs and received results are in the same reference mark (e.g.absolute) or where to check or set that.
Any suggested reference to appropriate literature to get knowledge on that topic is most welcome.

Thank you and best regards

Last edited by EnKiNekiDela (2022-09-08 18:57:48)

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Attachments:
Stage_2.comm, Size: 4.35 KiB, Downloads: 88

Viktor.Vlaski

Member

Registered: 2015-10-16

Posts: 20

Re: [SOLVED] DYNA_NON_LINE working with absolute/relative displacements

If in direct integration as input absolute displacement is used, than output is also absolute displacement. Theoretical background is explained for example at following link:

civilwares.free.fr/ForLinh/3D%20Static%20And%20Dynamic%20Analysis%20Of%20Structures%20-%20E%20Wilson.pdf

To verify numerically use linear modal and linear direct integration analyses: perform modal analysis - output is relative displacement, convert to absolute displacement and compare results to absolute displacement results of direct integration

EnKiNekiDela

Member

From: Slovenija

Registered: 2021-11-07

Posts: 24

Re: [SOLVED] DYNA_NON_LINE working with absolute/relative displacements

Thank you very much fo your help, I am looking into that.