Panel Buckling approach for bending

[stress_geek]

Hi there,
             How does Hypersizer solve buckling of flat plate with Longitudinal bending?
 Does it average just the negative running loads?

[Phil]

For a panel in pure bending (i.e. Mx or My), I don't think panel buckling comes into play.  You can have local instability. 

For example, for a honeycomb panel in bending, the top facesheet goes into compression and the bottom in tension (or vice versa), then the top facesheet can have wrinkling, dimpling and/or crimping, all local instability modes.  However the panel would not tend to buckling in this situation.

For a stiffened panel in bending, the face would be in compression and the stiffener in tension and again, you could have local buckling of the skin or cross-section crippling (both of which HyperSizer accounts for), but no panel buckling mode.

For panel buckling, HyperSizer uses only the Nx, Ny or Nxy loads.

Please let me know if this answers your question.
Phil

[stress_geek]

Suppose the plate is subjected to biaxial load and the load in one direction is positive. Does Hyperizer still account for this load in the equation where it calculates the critical Nx load?

[Phil]

Yes, if the load is biaxial, where Nx is compressive and Ny is tensile (or vice versa), HyperSizer does take advantage of the tensile stabilization that comes from tension in the transverse direction.

Therefore, if you have compression-tension, the buckling load will be higher than it would be if you have either uniaxial compression or if the panel is in compression-compression.

If you have HyperSizer installed, do a buckling analysis and then generate a Word Stress report.  There will be a section in the stress report that will describe HyperSizer's buckling method in pretty good detail.

Phil

[stress_geek]

Thanks. I have one other question. Does Hypersizer average just the negative shear elemental value or does it use the maximum between average negative shear and average positive shear in calculating the buckling M.S.?