Meaning of yield function in elastoplasticity

[joelle]

i'd like to know if it's possible what the meaning of yield function in elastoplasticity.
Also what is the concept of inelastic potential
i'll be thankful if someone can help me

 

[Astronuc]

Try these references for now -

http://www.ccad.uiowa.edu/projects/solidmech/micromechanics.html

http://www.ce.washington.edu/~geotech/const_model/ge_plastic/node2.html


With regard to inelastic potential, try

http://gltrs.grc.nasa.gov/reports/2003/TM-2003-212382.pdf - document page 3 (page 7 of pdf file).

an inelastic potential function based on the Drucker-Prager yield
criterion (Ref. 10) . . .

Ref 10. Khan, A.S.; and Huang, S.: Continuum Theory of Plasticity. John Wiley and Sons, Inc.,
New York, 1995.

 

[PerennialII]

Nice sources, in short the ingredients of typical plasticity models :

yield function : say $f(\sigma, q_{\alpha})$ where $\sigma$ is the true stress tensor and $q_{\alpha}$ are a set of internal variables - control onset and progress of plasticity

flow rule, flow potential - govern plastic flow, the increments of plastic strain, for example in incremental plasticity $\dot{\epsilon_{p}}=\dot{\lambda}\frac{\partial\psi}{\partial\sigma}$, where $\psi$ is the flow potential.

evolution equations - govern the behavior of internal variables, like strain hardening etc.

... typically metal plasticity models are associative, i.e. the flow potential and yield function are identical.