What's the difference between inelastic and plastic?
What's the difference between inelastic and plastic?
(OP)
Hello,
Is there a difference between inelastic and plastic, I know that they are the same literally but i ask if they have a different definition in structural analysis.
Is there a difference between inelastic and plastic, I know that they are the same literally but i ask if they have a different definition in structural analysis.






RE: What's the difference between inelastic and plastic?
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: What's the difference between inelastic and plastic?
another day in paradise, or is paradise one day closer ?
RE: What's the difference between inelastic and plastic?
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RE: What's the difference between inelastic and plastic?
another day in paradise, or is paradise one day closer ?
RE: What's the difference between inelastic and plastic?
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: What's the difference between inelastic and plastic?
RE: What's the difference between inelastic and plastic?
1) Cast iron. Neither plastic nor inelastic. Rather, I would characterize it as non-linear elastic up to brittle fracture.
2) Unreinforced concrete. Again, non-linear elastic up to fracture/crushing.
3) Reinforced concrete. Quite plastic and inelastic for most applications.
4) Steel. Plastic and inelastic so long as buckling is prevented.
Of course, few materials fit any model perfectly.
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: What's the difference between inelastic and plastic?
actually, i thought you'd cracked it with inelastic is non-linear elastic as opposed to plastic (with permanent deformation).
another day in paradise, or is paradise one day closer ?
RE: What's the difference between inelastic and plastic?
My $.02...
RE: What's the difference between inelastic and plastic?
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: What's the difference between inelastic and plastic?
RE: What's the difference between inelastic and plastic?
If you are talking about materials it can take on different meaning ie. a material modeled as elasto-plastic has a stress-strain curve that is linear in the elastic range and flat in the inelastic range (meaning additional strain/deformation without an increase in stress).
RE: What's the difference between inelastic and plastic?
My usage is:
Linear elastic: does what Robert Hooke said it should, or at least very nearly, since nothing has perfectly linear behaviour when loads are applied over a finite time.
Non-linear elastic: Non-linear stress-strain, but close to zero permanent strain when loads are removed.
Inelastic: Any behaviour that has significant permanent strain after removal of loads.
Plastic: Any permanent strain due to stresses exceeding a well defined yield stress.
Examples of inelastic behaviour that I would not call plastic are soil under loading and unloading, and reinforced concrete at first cracking.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: What's the difference between inelastic and plastic?
" if talking about a member "going inelastic" inelastic would refer to a ANY stresses in the member cross-section exceeding the yield stress where as the member is plastic once the ENTIRE cross-section reaches yield stress."
Why wouldn't you just say the member yielded, or exceeded its yield stress? Call a pig by another name, it's still a pig.
RE: What's the difference between inelastic and plastic?
Visco-elasticity is often described using the spring and dashpot model. The dashpot can be in parallel and or in series with the spring. Plastics have a relatively large viscous component whereas metals do not.
When "inelastic" is used in a scientific paper it means that the material does not have an elastic region in a stress/strain curve. So water would be "inelastic".
RE: What's the difference between inelastic and plastic?
Except when it means something else.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: What's the difference between inelastic and plastic?
RE: What's the difference between inelastic and plastic?
Because sometimes that's not all you are interested in. If your are limiting your analysis to first yield then, yes, it doesn't matter. If you are, for example, designing a plastic hinge, then it makes a difference as the capacity at first yield and at full yield are not the same.
RE: What's the difference between inelastic and plastic?
RE: What's the difference between inelastic and plastic?
Going back to my initial point of context... These details typically are of no consequence to a structural engineer but if you are a material scientist they probably are. It does not mean one is all of a sudden wrong. Its a matter of scale really.