Buckling Analysis

[BelghithiaN]

Hello to all,
i'm biginner in FEA Composite by abaqus software.
i have done a buckling analysis with 10 modes for a Composite component under pressure 0.001 MPa.
As results,(1) the eingenvalue for 1st buckling mode (as exemple) is equal to -0.0523. if it's correct as result, why it's negative value and very small?
(2) the load factor for 1st buckling mode is equal to eingenvalue.Applied load=-0.0523*0.001. it is correct?!!

thank you to answer me as soon as possible, I am in emergency project !!!

 

[BelghithiaN]

Hello

in same scenario, I have onther question: the Buckling load factor is it the eingenvalue given by abaqus for each mode ??!!
Please, i wait your response!!!

 

[jhardy1]

(1) the eingenvalue for 1st buckling mode (as exemple) is equal to -0.0523. if it's correct as result, why it's negative value and very small?
A negative Eigenvalue simply means that the structure would buckle with the loads acting in the reverse direction to how they have been modelled.

A typical thin-walled pressure vessel is more likely to burst than buckle under internal pressure loading, but it is very likely to buckle under small internal partial vacuum, unless designed specifically for such loading.

(2) the load factor for 1st buckling mode is equal to eingenvalue.Applied load=-0.0523*0.001. it is correct?!!
I can't possibly answer that! But if you have modelled the pressure vessel "correctly", then this should be the "correct" Eigenvalue / buckling factor for internal suction loading.

http://julianh72.blogspot.com

 

[BelghithiaN]

Thank you jhardy1 for this response

what is the buckling factor for internal section loading? it is a analytical value or given by a tabular data ?!!!
can you explain me more ?