Thread: Validity of bending equations under different conditions

Hi all,

I want to ask you a question about the bending moment equation:

Sigma= Moment * y / I

Does this equation have the same form if we assume,

-Plasticity instead of elasticity.
-Viscoelasticity instead of elasticity.
-Nonlinearity instead of linearity.
-Anisotropy instead of isotropy.

Can you please comment on the validity of the equation with these assumptions please.

Thanks.

It seems unlikely.
For example, elasticity considers the beam as a whole, plasticity is a deformation of the structure of the metal (the material of the beam).
One is (considered to be ) reversible, the other not.

Engineers tend to appreciate their equations being limited to simple, "unique" cases .

Originally Posted by Dywyddyr

It seems unlikely.
For example, elasticity considers the beam as a whole, plasticity is a deformation of the structure of the metal (the material of the beam).
One is (considered to be ) reversible, the other not.

Engineers tend to appreciate their equations being limited to simple, "unique" cases .

Plastic, elastic, mastic, and sarcastic: thus are we Engineers preoccupied. Design something within cost confines, guarantee it will injure or kill no one (except Munitions Engineering, of course!), hinge your reputation upon it, cheapen, oops, sorry, make it less costly to produce at the expense of potential falure, especially if being made for resale purposes. If for in-house use, spend the money up front, with assurance it will meet needs successfully.

Which equations shall we use? Almost all are approximations. jocular