Learning Forum

[gabriel.lucas]

Hello,

I have a working APDL macro that runs a transient simulation to obtain the equilibrium position of a steel catenary riser (SCR), I can provide this macro if needed. A transient analysis is done to obtain the equilibrium position due to the way the geometry is initialized. Three load steps are used to obtain the equilibrium configuration.
I would like to save the deformed geometry yielded from the last time step and use it into a modal analysis to obtain the natural frequencies as well as the mode shapes for the structure.
I have been trying some things but nothing worked out as expected until now. 
Does anyone have an idea on how I can do this?

Best regards,
Gabriel

[peteroznewman]

In APDL, the commands UPCOORD or UPGEOM are used to move node locations to their deformed position.

[gabriel.lucas]

Hello, 
Thank you for your response!
These were two commands I tried using but could not get them to work.

[ErKo]

 

 

Hello

See perhaps , how to run a linear perturbation analysis (modal). This will account for stress-stiffening/softening effects on the modes and use the deformed geom. from transient run (if nlgeom,on is used in the transient analysis).

See help for details and examples.

https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v261/en/ans_str/strlinpertproc.html

https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v261/en/ans_str/strlinpertinputs.html%23strlpexsimpmod

All the best

Erko

 

 

[gabriel.lucas]

Hello,
Thank you for your response!
I will try this suggestion!

[gabriel.lucas]

Hello, Erko
Just to let you know, I was able to perform the modal analysis I wanted to thanks to your help!
However, there is one thing I am still skeptical about, I am not sure the stress effects are being considered, because when i try to plot the stress contour, the model gets coloured by a single color. Maybe the stresses are not being saved in the results file and that is why I cannot plot them?