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Continuum damage model for simulation of the progressive failure of brittle rocks
319A 896243 Some remarks on the instantaneous response in rate-type viscoplasticity Suliciu, I int J Plasticity VS, N2, 1989, P173-181
model to describe anisotropic response of a brittle material due to growth of cracks under general applied loads. The model is tested numerically for a given cracked solid under a number of general plane strain loading conditions.
The conditions imposed on rate-type constitutive equations by the existence of the instantaneous elastic response are investigated. Isotropic materials, characterised by two constitutive functions, shear modulus and bulk modulus, which depend on stress only or stress and strain are considered.
896248 Incremental stress-strain relationships for regular packings made of multi-sized particles Chang, C S; Misra, A; Xue, J H lnt J Solids Struet V25, N6. 1989, P665-681
896244 Boundary element analysis of transient thermoelasticity Smith, D W; Booker, J R lnt J Nam Anal Meth Geomech V13, N3. May-June 1989, P283-302 A simple and efficient solution of uncoupled transient thermoelastic problems is presented. A Laplace transformation is used to temporarily remove time dependence of the governing equation, thus avoiding the costly evaluation of the domain integrals. Numerical analysis is carried out in the transform space. Boundary element and analytical methods are compared. Stress analysis of a deep mine indicates that significant tensile stresses may arise as the mine cools. 896245 Hylm-elastic analogues of the dilatant double-sliding model Kruyt, N P Int J Num Anal Meth Geomech V13, N3, May-June 1989, P303-308 Constitutive relations for two dimensional deformation of isotropic, rate independent cohesionless granular materials are considered. The relation between Mehrabadi and Cowin's dilatant double-sliding model and the hypo-elastic constitutive law is studied. Conditions which must be satisfied by hypoelastic analogues of the double-sliding model are derived. An example is given. 896246 Effect of Poisson's ratio and the far-field boundary conditions on the accuracy of finite element calculations. Short communication Fama, M E D Int J Num Anal Meth Geomeeh V13, N3, May-June 1989, P331-337 It is demonstrated that finite element problems involving an 'infinite medium' problem simulated by a mesh with finite boundaries will give more accurate results when stress boundary, rather than displacement boundary conditions, are applied. Accuracy is seriously impaired in the latter case when Poisson's ratio is close to 0.5. The 8-node quadratic isoparametric element is seen to give very accurate results for the axisymmetric thick cylinder with either type of boundary conditions. 896247 Continuum damage model for simulation of the progressive failure of brittle rocks Singh, U K; Digby, P J Int J Solids Struct V25, Nr, 1989, P647-663 The process of evolution of the microcrack pattern in a progressively failing brittle solid is reflected in an average sense by degradation of elastic stiffness. A set of continuous field variables, damage vectors, is introduced and used in a constitutive
The mechanical behaviour of a granular system is greatly influenced by its packing geometry. In this work, the concept of 'Voronoi polyhedron' is utilised to characterise granular packings, and it is shown that polyhedral tesseilations can be used to represent packings of multi-sized particles. A stressstrain theory, based on micro-mechanical considerations, for small deformations of such packings is then described. The derived stress-strain relationship is compared with experimental results. Auth. 896249 Supercomputer assisted three-dimensional finite element analysis of a iongwail panel Park, D W; Gall, V Rock Mechanics as a Guide for E.~icient Utilization of Natural Resources: Proc 30th U.S. Symposium, Morgantown, 19-22 June 1989 P133-140. Publ Rotterdam: A A Baikema, 1989 A three dimensional finite element analysis of a longwall panel is described. The model covers an area of llr0fl by 1060ft with total height 2130ft, and is large enough to represent realistic behaviour of the strata. The progressive failure technique is used to simulate stress redistribution, and a computer program has been developed to automate its application. The CRAY X-MP/24 supercomputer was used in the work. 896250 Brief review of constitutive models Saada, A Proe International Workshop on Constitutive Equationsfor Granular Non-Cohesive Soils, Cleveland, 22-24 July 1987 P710. Publ Rotterdam: A A Balkema, 1989 Constitutive models and failure criteria applicable to cohesionless soils are summarised, including deformation theories, incremental theories, elastoplastic theories with isotropic and anisotropic behaviour, endochronic theory, and anisotropic and isotropic failure criteria. Fundamental problems of the models are briefly discussed. 60 refs 896251 Different classes of constitutive equations and their characteristics Darve, F; Dendani, H; Chau, B Proc International Workshop on Constitutive Equationsfor Granular Non-Cohesive Soils, Cl~eland, 22-24 July 1987 P11-17. Publ Rotterdam: A A Balkema, 1989 An introduction to the incremental formulation of constitutive equations is presented. The concept of the tensorial zone is described and used to classify constitutive equations in relation to the number of their tensorial zones. The influence of this constitutive structure on the predictive capacity of the equations is demonstrated by comparing undrained triaxial and deviatoric circular stress path responses for linear, ottolinear and nonlinear constitutive relations.
© 1989 Pergamon Press pic. Reproduction not permitted
model to describe anisotropic response of a brittle material due to growth of cracks under general applied loads. The model is tested numerically for a given cracked solid under a number of general plane strain loading conditions.
The conditions imposed on rate-type constitutive equations by the existence of the instantaneous elastic response are investigated. Isotropic materials, characterised by two constitutive functions, shear modulus and bulk modulus, which depend on stress only or stress and strain are considered.
896248 Incremental stress-strain relationships for regular packings made of multi-sized particles Chang, C S; Misra, A; Xue, J H lnt J Solids Struet V25, N6. 1989, P665-681
896244 Boundary element analysis of transient thermoelasticity Smith, D W; Booker, J R lnt J Nam Anal Meth Geomech V13, N3. May-June 1989, P283-302 A simple and efficient solution of uncoupled transient thermoelastic problems is presented. A Laplace transformation is used to temporarily remove time dependence of the governing equation, thus avoiding the costly evaluation of the domain integrals. Numerical analysis is carried out in the transform space. Boundary element and analytical methods are compared. Stress analysis of a deep mine indicates that significant tensile stresses may arise as the mine cools. 896245 Hylm-elastic analogues of the dilatant double-sliding model Kruyt, N P Int J Num Anal Meth Geomech V13, N3, May-June 1989, P303-308 Constitutive relations for two dimensional deformation of isotropic, rate independent cohesionless granular materials are considered. The relation between Mehrabadi and Cowin's dilatant double-sliding model and the hypo-elastic constitutive law is studied. Conditions which must be satisfied by hypoelastic analogues of the double-sliding model are derived. An example is given. 896246 Effect of Poisson's ratio and the far-field boundary conditions on the accuracy of finite element calculations. Short communication Fama, M E D Int J Num Anal Meth Geomeeh V13, N3, May-June 1989, P331-337 It is demonstrated that finite element problems involving an 'infinite medium' problem simulated by a mesh with finite boundaries will give more accurate results when stress boundary, rather than displacement boundary conditions, are applied. Accuracy is seriously impaired in the latter case when Poisson's ratio is close to 0.5. The 8-node quadratic isoparametric element is seen to give very accurate results for the axisymmetric thick cylinder with either type of boundary conditions. 896247 Continuum damage model for simulation of the progressive failure of brittle rocks Singh, U K; Digby, P J Int J Solids Struct V25, Nr, 1989, P647-663 The process of evolution of the microcrack pattern in a progressively failing brittle solid is reflected in an average sense by degradation of elastic stiffness. A set of continuous field variables, damage vectors, is introduced and used in a constitutive
The mechanical behaviour of a granular system is greatly influenced by its packing geometry. In this work, the concept of 'Voronoi polyhedron' is utilised to characterise granular packings, and it is shown that polyhedral tesseilations can be used to represent packings of multi-sized particles. A stressstrain theory, based on micro-mechanical considerations, for small deformations of such packings is then described. The derived stress-strain relationship is compared with experimental results. Auth. 896249 Supercomputer assisted three-dimensional finite element analysis of a iongwail panel Park, D W; Gall, V Rock Mechanics as a Guide for E.~icient Utilization of Natural Resources: Proc 30th U.S. Symposium, Morgantown, 19-22 June 1989 P133-140. Publ Rotterdam: A A Baikema, 1989 A three dimensional finite element analysis of a longwall panel is described. The model covers an area of llr0fl by 1060ft with total height 2130ft, and is large enough to represent realistic behaviour of the strata. The progressive failure technique is used to simulate stress redistribution, and a computer program has been developed to automate its application. The CRAY X-MP/24 supercomputer was used in the work. 896250 Brief review of constitutive models Saada, A Proe International Workshop on Constitutive Equationsfor Granular Non-Cohesive Soils, Cleveland, 22-24 July 1987 P710. Publ Rotterdam: A A Balkema, 1989 Constitutive models and failure criteria applicable to cohesionless soils are summarised, including deformation theories, incremental theories, elastoplastic theories with isotropic and anisotropic behaviour, endochronic theory, and anisotropic and isotropic failure criteria. Fundamental problems of the models are briefly discussed. 60 refs 896251 Different classes of constitutive equations and their characteristics Darve, F; Dendani, H; Chau, B Proc International Workshop on Constitutive Equationsfor Granular Non-Cohesive Soils, Cl~eland, 22-24 July 1987 P11-17. Publ Rotterdam: A A Balkema, 1989 An introduction to the incremental formulation of constitutive equations is presented. The concept of the tensorial zone is described and used to classify constitutive equations in relation to the number of their tensorial zones. The influence of this constitutive structure on the predictive capacity of the equations is demonstrated by comparing undrained triaxial and deviatoric circular stress path responses for linear, ottolinear and nonlinear constitutive relations.
© 1989 Pergamon Press pic. Reproduction not permitted