Microplane constitutive model for porous isotropic rocks

Zdeněk P. Bažant1, Goangseup Zi2
1Department of Civil Engineering, Northwestern University, Evanston, IL 60208 USA
2Northwestern University

Tóm tắt

AbstractThe paper deals with constitutive modelling of contiguous rock located between rock joints. A fully explicit kinematically constrained microplane‐type constitutive model for hardening and softening non‐linear triaxial behaviour of isotropic porous rock is developed. The microplane framework, in which the constitutive relation is expressed in terms of stress and strain vectors rather than tensors, makes it possible to model various microstructural physical mechanisms associated with oriented internal surfaces, such as cracking, slip, friction and splitting of a particular orientation. Formulation of the constitutive relation is facilitated by the fact that it is decoupled from the tensorial invariance restrictions, which are satisfied automatically. In its basic features, the present model is similar to the recently developed microplane model M4 for concrete, but there are significant improvements and modifications. They include a realistic simulation of (1) the effects of pore collapse on the volume changes during triaxial loading and on the reduction of frictional strength, (2) recovery of frictional strength during shearing, and (3) the shear‐enhanced compaction in triaxial tests, manifested by a deviation from the hydrostatic stress–strain curve. The model is calibrated by optimal fitting of extensive triaxial test data for Salem limestone, and good fits are demonstrated. Although these data do not cover the entire range of behaviour, credence in broad capabilities of the model is lend by its similarity to model M4 for concrete—an artificial rock. The model is intended for large explicit finite‐element programs. Copyright © 2002 John Wiley & Sons, Ltd.

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Tài liệu tham khảo

Costin LS, 1985, A microcrack model for the deformation and failure of brittle rock, Journal of Geophysical Research, 88, 9485, 10.1029/JB088iB11p09485

10.1016/S0148-9062(97)00340-9

10.1016/S0167-6636(00)00005-3

10.1016/S0167-6636(00)00006-5

10.1016/S0167-6636(00)00024-7

Pan YW, 2001, Constitutive model for the continuous damage of brittle rock, Géotechnique, 51, 155, 10.1680/geot.2001.51.2.155

10.1016/0167-6636(85)90007-9

10.1016/0148-9062(92)91043-5

Taylor GI, 1938, Plastic strain in metals, The Journal of the Institute of Metals, 62, 307

BatdorfSB BudianskiB.A mathematical theory of plasticity based on the concept of slip. Technical Note No. 1871 National Advisory Committee for Aeronautics: Washington DC 1949.

10.1016/0001-6160(61)90060-8

Budiansky B, 1962, Proceedings of 4th U.S. National Congress of Applied Mechanics, 1175

10.1016/0022-5096(65)90024-4

10.1016/0022-5096(65)90023-2

10.1016/0022-5096(66)90040-8

10.1115/1.3408603

10.1002/nag.1610010302

Pande GN, 1981, Proceedings of Symposium on Implementation of Computer Procedures and Stress–Strain Laws in Geotechnology Engineering, 575

Pande GN, 1983, Multi‐laminate model of clays—a numerical evaluation of the influence of rotation of the principal stress axes, Journal of Engineering Mechanics ASCE, 109, 397

Pande GN, 1982, Proceedings of the First International Symposium on Numerical Models in Geomechanics, 218

Bažant ZP, 1984, Mechanics of Engineering Materials, 45

10.1061/(ASCE)0733-9399(1985)111:4(559)

Bažant ZP, 1976, Instability, ductility, and size effect in strain‐softening concrete, Journal of Engineering Mechanics ASCE, 102, 331

Bažant ZP, 1983, Crack band theory for fracture of concrete, Materials and Structures, 16, 155

10.1115/1.3097329

10.1061/(ASCE)0733-9399(1988)114:10(1672)

10.1061/(ASCE)0733-9399(2000)126:9(944)

10.1016/S0020-7683(96)00238-7

10.1016/S0020-7683(00)00212-2

10.1061/(ASCE)0733-9399(1988)114:10(1689)

10.1061/(ASCE)0733-9399(1996)122:3(245)

10.1061/(ASCE)0733-9399(1996)122:3(255)

Caner FC, 2000, Microplane Model M4 for Concrete II: algorithm and calibration, Journal of Engineering Mechanics ASCE, 126, 954, 10.1061/(ASCE)0733-9399(2000)126:9(954)

10.1002/nme.253

Bažant ZP, 1998, Fracture and Size Effect: in Concrete and Other Quasibrittle Materials

Jirásek M, 2002, Inelastic Analysis of Structures

Bažant ZP, 2000, Fracture rate effect and creep in microplane model for dynamics, Journal of Engineering Mechanics ASCE, 126, 955, 10.1061/(ASCE)0733-9399(2000)126:9(962)

10.1061/(ASCE)0733-9399(2002)128:1(24)

10.1061/(ASCE)0733-9399(1992)118:7(1365)

BažantZP ZiG JendeleL.Microplane model for quasibrittle materials based on fracture energy of cohesive crack.2002; in preparation.

Bažant ZP, 1987, Creep of anisotropic clay: new microplane model, Journal of Engineering Mechanics ASCE, 113, 1000, 10.1061/(ASCE)0733-9399(1987)113:7(1050)

10.1061/(ASCE)0733-9410(1991)117:6(891)

10.1016/S0022-5096(01)00112-0

10.1016/S0020-7683(01)00007-5

10.1002/zamm.19860660108

10.1061/(ASCE)0733-9399(1991)117:10(2429)

Bažant ZP, 1991, Stability of Structures

JirásekM.Modeling of fracture and damage in quasibrittle materials. Ph.D. Dissertation Northwestern University: Evanston IL 1993.

10.1016/S0020-7683(00)00177-3

10.1061/(ASCE)0733-9445(1984)110:9(2015)

SferD CarolI GettuR EtseG.Experimental study of the triaxial behaviour of concrete. Report GT021/2000 ETECCPB (Sch. of C. E. UPC): Barcelona Spain 2000.

10.2516/ogst:1999061

GreenML. Mechanical response of SRII Salem Limestone. Report CEWES‐SD‐0 (70‐1r). Waterways Experiment Station 1993.

Baud P, 1999, Dilatancy, compaction, and failure mode in Solnhofen limestone, Journal of Geophysical Research, 105

Bažant ZP, 2001, Fracture Mechanics of Concrete Structures, 765

Červenka J, 2002, Equivalent localization element for crack band approach to mesh‐size sensitivity in microplane model, International Journal for Numerical Methods in Engineering

10.1061/(ASCE)0733-9399(1990)116:11(2485)

di LuzioG BažantZP CedolinL.Nonlocal generalization of microplane model. Report Northwestern University. International Journal of Solids and Structures 2002;to be submitted.

10.1061/(ASCE)0733-9399(2002)128:11(1119)