buckling load factor for non buckling geometry
buckling load factor for non buckling geometry
(OP)
Hello,
I know that a short geometry (or massive solid geometry) fails by crashing and not buckling. But I want to compare buckling load factors (Eulerian buckling) for a short structure with different softwares (even if there is no physical sense).
Buckling analysis with a FEA software is supposed to be a mathematical problem depending of the stiffness of the structure. So with the same stiffness (regardless the reality of physical solution) we should obtain the same buckling load factor beetwen different softwares.
I have done a benchmark for a short geometry (same boundaries conditions, fixed support and compressive pressure) beetwen different softwares and results on buckling load factors are not the same (30% of difference).
Do you have an explanation ?
thanks
regards
I know that a short geometry (or massive solid geometry) fails by crashing and not buckling. But I want to compare buckling load factors (Eulerian buckling) for a short structure with different softwares (even if there is no physical sense).
Buckling analysis with a FEA software is supposed to be a mathematical problem depending of the stiffness of the structure. So with the same stiffness (regardless the reality of physical solution) we should obtain the same buckling load factor beetwen different softwares.
I have done a benchmark for a short geometry (same boundaries conditions, fixed support and compressive pressure) beetwen different softwares and results on buckling load factors are not the same (30% of difference).
Do you have an explanation ?
thanks
regards






RE: buckling load factor for non buckling geometry
2) Is the element type used in the different FEM packages different?
3) Are the two software packages both handling non-linearity in the same manner (or not at all)?
Frankly, I'm surprised by your strategy. Why not compare results for a longer member for which Fcr makes physical sense?
What are you looking at here? Column? Plate? Are you comparing to hand calculated results as well?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: buckling load factor for non buckling geometry
1) The mesh is quite the same and a mesh refinement has been studied to verify the sensibility. This is not a mesh problem.
2) The element type formulation is different beetween FEM package but several elements types have been studied and no particular variation has been observed for BLF.
3) There is no non-linearity : linear elastic material, no contact, small displacement.
My goal is to quantify the error diffusion in BLF gradually as the geometry becomes short.
For exemple you can have this kind of results :
Slender geometry : Software 1 and 2 BLF correspond each other,
middle geometry : Software 1 and 2 BLF begin to diverge,
short geometry : Software 1 and 2 BLF are quite different.
Which one departs furthest from reality when the geometry becomes short ? Which one have biggest error diffusion and how to quantify this error ?
Thanks
Regards
RE: buckling load factor for non buckling geometry
Please let me know if you have some references.
thanks
RE: buckling load factor for non buckling geometry
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: buckling load factor for non buckling geometry
RE: buckling load factor for non buckling geometry