KAYENTA : theory and user's guide.

Brannon, Rebecca Moss (University of Utah, Salt Lake City, UT) ; Fossum, Arlo Frederick (BP America, Inc., Houston, TX) ; Strack, Otto Eric

Sandia National Laboratories

关键词: Hardening;    Strain Rate-Materials-Mathematical Models.;    Anisotropy;    36 Materials Science;    Elasticity;   

DOI  :  10.2172/984159
RP-ID  :  SAND2009-2282
RP-ID  :  AC04-94AL85000
RP-ID  :  984159

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来源: UNT Digital Library

【 摘 要 】

The physical foundations and domain of applicability of the Kayenta constitutive model are presented along with descriptions of the source code and user instructions. Kayenta, which is an outgrowth of the Sandia GeoModel, includes features and fitting functions appropriate to a broad class of materials including rocks, rock-like engineered materials (such as concretes and ceramics), and metals. Fundamentally, Kayenta is a computational framework for generalized plasticity models. As such, it includes a yield surface, but the term 'yield' is generalized to include any form of inelastic material response including microcrack growth and pore collapse. Kayenta supports optional anisotropic elasticity associated with ubiquitous joint sets. Kayenta supports optional deformation-induced anisotropy through kinematic hardening (in which the initially isotropic yield surface is permitted to translate in deviatoric stress space to model Bauschinger effects). The governing equations are otherwise isotropic. Because Kayenta is a unification and generalization of simpler models, it can be run using as few as 2 parameters (for linear elasticity) to as many as 40 material and control parameters in the exceptionally rare case when all features are used. For high-strain-rate applications, Kayenta supports rate dependence through an overstress model. Isotropic damage is modeled through loss of stiffness and strength.