TRESCA stress definition

[jonmaddock]

In GitLab by @skahn on Jan 16, 2020, 16:42

Summary

Following the defintion of the different stresses on wikipedia page https://en.wikipedia.org/wiki/Yield_surface#von_Mises_yield_surface, the TRESCA stress is half the one used in PROCESS, while the Von-Mises is the same. What should we do about this ?

Ref : @mkovari, @jmorris-uk, @stuartmuldrew

Cheers
Seb

[jonmaddock]

In GitLab by @skahn on Jan 20, 2020, 16:16

Mis-undertanding, of the definition. Closing the issue

[jonmaddock]

In GitLab by @skahn on Jan 20, 2020, 16:16

closed

[jonmaddock]

In GitLab by @mkovari on Jan 4, 2021, 17:19

Sorry, Seb, I don't think I ever looked at this issue. It turns out that the term "Tresca stress" is not well defined. See, for example the lengthy discussion here. For example:

This is pretty unscientific but I found 21 sources (journal articles, books, FEA software manuals) that describe the Tresca criterion:
3/21: Tresca stress refers to maximum shear stress
1/21: Tresca stress refers to 2 x maximum shear stress
2/21: Tresca equivalent stress refers to 2 x maximum shear stress
2/21: stress intensity refers to 2 x maximum shear stress
17/21: No use of the term Tresca stress that I could find.

The term "Tresca stress" should be removed. The "maximum shear stress" should be output instead. (Note that "stress intensity", the term used by Ansys, should also be avoided as it risks confusion with stress intensity factor - a completely different concept.)

Any volunteers @skahn @ajpearcey @stuartmuldrew ?

[jonmaddock]

In GitLab by @mkovari on Jan 4, 2021, 17:19

reopened

[grmtrkngtn]

@mkovari as I understand this, you are proposing to change any mention of tresca to something like max_shear_stress?

[mkovari]

Yes.

[grmtrkngtn]

@chris-ashe what do you think of the variable change I have made in the branch? does it match the new convention well enough?