Buckling Analysis - Identifying modes

[RRufino]

Hi all,

Every time i try to use Buckling Analysis in non symmetric and non regular structure i get really confused how to deal with it.

Please check random model in attachment. It has buckling analysis on combination 12 and i get alfacr<10 for first mode, how can i know if this mode is relevant or not? By checking mode shape i cannot get an answer to my question, have you?

Tips and tricks are appreciated, i'm always feeling that i'm not taking advantage of robot capabilities.

Thanks in advance,
RR

[Rafacascudo]

check the % of total mass it uses.The more mass , the more relevant

[RRufino]

Hi Rafacascudo,

I'm refering to buckling modes not modal analysis, i think that's not possible on ARSA to see that on the first issue.

Thanks

[Pawel.Pulak · Accepted solution]

It is visible that for the attached model the buckling mode 1 is related to buckling in global Y direction.

See this video:

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Regards,

[RRufino]

Thanks pp2008, i suppose that doesn't exist a straight way then guess it by mode shapes.

[teixeiranh]

I guess you're right.

Sometimes it is pretty obvious, sometimes is not. Sometimes the structure is just not well modeled and one needs to change some kind of realese and /or bar stiffness. When I get "weird" modes I try to model the structure in a different way...bu it can be confusing, as the structure gets more complicated.