Abaqus load cases for frequency analysis....

[gregf84]

Hello,
I am trying to convert an Abaqus Standard 3D model to an Opticstruct model and I have not used Abaqus for 14 years, so I am unfamiliar with the load cases for Abaqus. I am using Hypermesh to view the Abaqus model. When I look at the Abaqus model in Hypermesh, I see the following: StepParameters (has checkmark), Increment (has checkmark), Nlgeom (has checkmark), Static Riks_Stabilize dataline (has checkmark). Therefore these options are to be in effect for the Abaqus model analysis. In more detail the Abaqus model has the following cards: *STEP, INC =100, NLGEOM =yes, *STATIC Init_Inc =0.1, T_Period=1.0, Minlncr = 1.0e-06, SPC_Load.1, *Control, Parameters = time Incremention I_O, I_R, I_P, I_C, I_L, I_G, I_S, I_A, *Node file, Frequency =10, U, *El File, Frequency = 20, SINV, *END STEP
Can anyone tell me exactly what is this analysis be in the Abaqus model? It looks like a normal modes analysis but normal modes is typically a linear analysis in Optistruct and the Abaqus model has a nonlinear card specified? I want to try and run in Opticstruct an analysis that is similar to or the same as was specified in the Abaqus model.

 

[testing]

Based on what you wrote, it looks like it's doing a Rik's Buckling analysis. The "frequency" terms you see are controlling the output frequency of the results. For a frequency analysis, you would want a *FREQUENCY step rather than a *STATIC step. Check the Abaqus manual for more information.

 

[gregf84]

Hello zwtipp05,
Thanks for the feedback. I do not have a manual for Abaqus. I do not even have the solver for Abaqus. I only want to convert so that I can run the model in Opticstruct if possible. I am relying on my memory of Abaqus from 14 years back. Is riks buckling a nonlinear geomtery buckling method? The Abaqus model specifies NlGeom=yes. I am wondering if this can be simulated in Opticstruct.

 

[testing]

I haven't even heard of opticstruct, so can't help you there. You should be able to find Abaqus documentation with a minimal Googling effort

 

[IceBreakerSours]

Is riks buckling a nonlinear geomtery buckling method?

Yes.

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