Short column buckling theory
Short column buckling theory
(OP)
My Canadian colleague is taking me to task for not being familiar with Johnston column buckling theory. After some poking around it looks like Johnston developed a tangent modulus theory to describe the inelastic buckling of columns. I also see a single reference to his name in my 1000 page university text. It's not something that I see very often but I think AISC uses a less conservative method of reduced modulus. Does anyone know any background on this and why one is used over the other when you are outside the elastic/Euler range?
Also just as a refresher, what are some design scenarios where inelastic column buckling modes are common?
TIA
Also just as a refresher, what are some design scenarios where inelastic column buckling modes are common?
TIA






RE: Short column buckling theory
RE: Short column buckling theory
This article sheds some light on the subject:
http://www.efunda.com/formulae/solid_mechanics/col...
BA
RE: Short column buckling theory
Also just as a refresher, what are some design scenarios where inelastic column buckling modes are common?
Almost all design scenarios actually. Using BA's definitions, which are the right ones, it's pretty rare to have either long or short columns. A short column suggests inefficiency; a long column suggests a high slenderness ratio and perhaps madness.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Short column buckling theory
BA
RE: Short column buckling theory
Inelastic buckling is probably the most common scenario for steel buildings. If you look at AISC 14th edition, equation E3-3 is based on Euler buckling. But, equation E3-2 is based on inelastic buckling.