Neglecting geometric and material non-linearities, are post-buckling deformations necessarily within the nonlinear stress-strain regime? I am trying to see if buckling forces are a good gauge to be used for linear elasticity assumption, i.e. post-buckling, linear elasticity is not a valid assumption. I am assuming the material is linear elastic.
I was told by a support engineer at COMSOL to run buckling analysis to see how much compression my structure handles before buckling to see if linear elasticity is a good assumption. I don't see the connection between buckling and elastic nonlinearity. A linear and/or nonlinear elastic material post-buckling will deform back to the original shape when unloaded. Is it correct to say buckling is irrelevant to material non-linearity?
hi
when dealing with buckling and its relation with material plasticity, we three general cases:
1- elastic buckling occures before yeilding of material. just right after the elastic buckling load, the stiffness of structure decreases then yeilding load is obtained followed by reaching ultimate strength
2- buckling load almost equal yeilding load (elastic plastic buckling). in this case the behavior is characterised by sharp decrease in the strength in the post
ultimate regime.
3-- yeilding is reached frist, and buckling occurs later (plastic buckling case)
you cand create a model of simply supported square plate and apply in-plane load along its edge. change the thickness . this is a good example to practice the above case of buckling
you need to input initial deflection to initiate the buckling in nonlinear analysis.
Sorry Javid i had final exams, couldn't reply. In post-buckling it is possible to have large strains, which calls for nonlinear stress-strain relations for most metals. When the structure buckles it fails and does not come back much. It either breaks or stays permanently deformed a lot. If you run a simulation until buckling, it will tell you when the system will transition from yielding to buckling. A buckling analysis is characterized by the analysis failing and not completing. This is when you know you hit the buckling failure mode. If the structure becomes plastic, of course, the deflection is irreversible.
I would agree that it is not dependent!
In practice , in the case of building structures the buckling will not be regained at all as in the case of a cyclic loading. stability analysis will help you
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