A general smooth and convex yield function is proposed, able to model the particular behavior of geomaterials, particularly rock materials that are characterized by a linear or parabolic Mohr's envelope, and a particular shape in the deviatoric plane. These characteristics are defined by two functions: the equation of the criterion in the meridian plane and the extension ratio, which are integrated in a general equation ensuring convexity and smoothness of the yield function, whatever the characteristic functions. This expression is interesting, because it allows a straightforward development of a constitutive model based on triaxial tests, in extension and compression. It also allows the development of smooth criteria corresponding to the Mohr-Coulomb criterion and the Hœk-Brown criterion, the latter typical of rock mechanics. © 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved.
Maïolino, S. (2005). Proposition of a general yield function in geomechanics. Comptes Rendus - Mecanique, 333(3), 279–284. https://doi.org/10.1016/j.crme.2004.11.008