Needs a diagram, equations, and example input/output

[rcc02007]

@auh16102 :
I like this idea of building a failure criteria using buckling. Nice work so far. One fundamental question:
what happens if the column is very wide e.g. aspect ratio <1 (height/diameter)?
Many failure methods will check both uniaxial stress and buckling load. Then, you can compare which one happens first.

Some missing pieces for this work:

• An engineering diagram with a free body diagram
• Equations used with references
• Example use cases with inputs and outputs -> How do you use this code?

These would typically go or have a link in the README.