Buckling analysis of a preloaded square plate using FEA (Nastran)

[JSF10]

Dear Sir/Madam,
I would like to know how to do buckling analysis on a square plate that is already been pre-loaded under a shear load (qb).

That is I have a square plate model that needs to be stressed by loading in shear (qb) initially along the two plate (left & right) edges. Then I need to do a linear buckling solution to find how much compressive load (fb) is required (on the plate left and right edges) for the buckling to take place. How do I initially apply the shear pre-load (qb) to pre-stress the plate before loading the compressive load (fb) to analyse the linear buckling load.

For your information I am using Msc Nastran for windows.

Any help would be gratefully appreciated. Many thanks for looking into my problem.

Best Regards

 

[40818]

I wouldn't even bother doing an FE model, just have a look at some shear and biaxial compression work. An example of this (which isn't proprietry) is ESDU81047 is what your looking for if you want a program to do the sums for you. Or take a look in some decent books which will give you what you want. Or you could carry out an interaction type equation to combine the reserve factors for a quick ball park answer.

Or if you want to do the FE, i would not model this combination by a linear buckling model, the results you get out are likely to be garbage.

 

[rb1957]

look up diagonal tension analysis (flat panels loaded in shear and compression) in Bruhn (chapter C11 pt1) or NACA TN 2661 and 2662.

or if your design is intended to be shear resistant (non-buckling) (also = heavier) then Bruhn chapter C10 would answer.