Imperfection in Hyperworks/Optistruct

Hi,

I am wanting to include geomtry imperfection input in my model.

However, looks like I cannot find the keyword card?

I am wondering if there is still an option of 2022.3 version of Hyperworks and optistruct?

https://help.altair.com/hwsolvers/os/topics/solvers/os/analysis_technique_imperfection_r.htm?zoom_highlight=linear+buckling

Best,

Jerome.

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Accepted answers

RobinsonFerrari

Hi Jerome,

Please find attached an example model to be used as a reference.

The model approach can be summarized as:

Basically, you need to run a linear problem to obtain normal modes. Then use this .h3d file with ASSIGN in the nonlinear model to define an IMPERF load collector. Use it in the nonlinear subcase with NLPARM (options NLPCI).

In HyperWork, you can right-click in the model browser (card) to create a CARD by selecting ASSIGN. (Select type: H3DRES). Right-click in the model browser again to create a load collector, and select CARD IMAGE: IMPERF. Please see the pictures below.

Please consider marking this answer as correct if this works for you.

Thank you very much,

IMPERFECTION_EXAMPLE.7z

All comments

RobinsonFerrari

Hi Jerome,

Please find attached an example model to be used as a reference.

The model approach can be summarized as:

Please consider marking this answer as correct if this works for you.

Thank you very much,

IMPERFECTION_EXAMPLE.7z

jerometeoh

Robinson,

Thank you; this helps.

Please excuse me for one more question.

When running a linear static analysis before the linear buckling anlaysis, do we typically define compression force instead of displacement load? If so, should I use 1N for reference load or it depend on the strucuture?

I ask this because I usually use displacement load, enforced displacement (the SPC card).

I am wondering if I can use SPC and export the SPC force later. Am I still able the relate the resultant load factor to the minimal buckling load?

Thank you,

Jerome.

Kacper_S

Robinson,

Thank you; this helps.

Please excuse me for one more question.

When running a linear static analysis before the linear buckling anlaysis, do we typically define compression force instead of displacement load? If so, should I use 1N for reference load or it depend on the strucuture?

I ask this because I usually use displacement load, enforced displacement (the SPC card).

I am wondering if I can use SPC and export the SPC force later. Am I still able the relate the resultant load factor to the minimal buckling load?

Thank you,

Jerome.

I would like to know too

Is it possible to get safety factor for buckling in nonlinear step with imperfection