Geostar (non-linear) how to release constraints
Geostar (non-linear) how to release constraints
(OP)
Hello - please disregard my previous post... I'm hoping that the Lack responses was only my vagueness and not a lack of members using COSMOS anymore!
searching online and finding early press releases, I read that one of the strengths of Cosmos/m / Geostar is the ability to release and activate constraints during a non linear analysis...
Anyone know how to specifically do this?
here is my problem:
I am trying to analysis a 3d beam / truss structure with adjustable linkages...using temp curves to pretension and adjust the structure. getting this all to run to equilibrium is very tricky. I'd like to fix a few points as I bring the structure up to tension - and then release these constraints for the subsequent time steps.
I have time/temp curve defined, and associated the point constraint to this - but as far as I can figure out this just allows me to change it from 0 (fixed) to some value (prescribed displacement) - not completely disable it.
Anyone know a better way to do this?
thanks
Andrew
searching online and finding early press releases, I read that one of the strengths of Cosmos/m / Geostar is the ability to release and activate constraints during a non linear analysis...
Anyone know how to specifically do this?
here is my problem:
I am trying to analysis a 3d beam / truss structure with adjustable linkages...using temp curves to pretension and adjust the structure. getting this all to run to equilibrium is very tricky. I'd like to fix a few points as I bring the structure up to tension - and then release these constraints for the subsequent time steps.
I have time/temp curve defined, and associated the point constraint to this - but as far as I can figure out this just allows me to change it from 0 (fixed) to some value (prescribed displacement) - not completely disable it.
Anyone know a better way to do this?
thanks
Andrew






RE: Geostar (non-linear) how to release constraints
It's years I don't use COSMOS/M GEOSTAR anymore, but the only feature available in any serious FEA code is RESTART feature:
Suppose that a Nonlinear problem diverged at solution step number 5. Activating restart feature you can change the solution time increment, or some other parameters like loads & BCs. If the restart feature is OFF and you run the nonlinear analysis again, the solution will start from step 1 ignoring previous results. If the restart flag is ON, the solution will continue from step 5.
Good luck!.
Best regards,
Blas.
~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director
IBERISA
48011 BILBAO (SPAIN)
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RE: Geostar (non-linear) how to release constraints
My 2 cents.
TOP
CSWP, BSSE
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RE: Geostar (non-linear) how to release constraints
If you do it in one jump you have to use a Dynamic Solution. If you ramp it a little you can get away with a Standard non-linear solution.
You have to activate the time curve before you define the constraint that will be effected by it.
For example executing this:
CODE
TOP
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