Anisotropic dynamic damage and fragmentation of rock materials under explosive loading

This paper describes the development of a constitutive model for predicting dynamic anisotropic damage and fragmentation of rock materials under blast loading. In order to take account of the anisotropy of damage, a second rank symmetric damage tensor is introduced in the present model. Based on the mechanics of microcrack nucleation, growth and coalescence, the evolution of damage is formulated. The model provides a quantitative method to estimate the fragment distribution and fragment size generated by crack coalescence in the dynamic fragmentation process. It takes account of the experimental facts that a brittle rock material does not fail if the applied stress is lower than its static strength and certain time duration is needed for fracture to take place when it is subjected to a stress higher than its static strength. Numerical results are compared with those from independent field tests.

[1]  P. D. Katsabanis,et al.  DEVELOPMENT OF A CONTINUUM DAMAGE MODEL FOR BLASTING ANALYSIS , 1997 .

[2]  S. Murakami,et al.  Notion of Continuum Damage Mechanics and its Application to Anisotropic Creep Damage Theory , 1983 .

[3]  F. A. Leckie,et al.  Representation of Mechanical Behavior in the Presence of Changing Internal Structure , 1988 .

[4]  L. G. Margolin,et al.  Elastic moduli of a cracked body , 1983 .

[5]  B. Atkinson.  Fracture Mechanics of Rock , 1987 .

[6]  G. Swoboda,et al.  An energy-based damage model of geomaterials-I. Formulation and numerical results , 1999 .

[7]  Dusan Krajcinovic,et al.  The Continuous Damage Theory of Brittle Materials, Part 1: General Theory , 1981 .

[8]  D. Krajcinovic,et al.  A constitutive theory for progressively deteriorating brittle solids , 1987 .

[9]  S. Murakami,et al.  Mechanical Modeling of Material Damage , 1988 .

[10]  M. E. Kipp,et al.  10 – DYNAMIC ROCK FRAGMENTATION , 1987 .

[11]  B. Budiansky,et al.  Elastic moduli of a cracked solid , 1976 .

[12]  W. F. Bawden,et al.  A new constitutive model for blast damage , 1996 .

[13]  C. L. Chow,et al.  On evolution laws of anisotropic damage , 1989 .

[14]  J. C. Simo,et al.  Strain- and stress-based continuum damage models—I. Formulation , 1987 .

[15]  Dusan Krajcinovic,et al.  Constitutive Equations for Damaging Materials , 1983 .

[16]  H. Saunders,et al.  Advanced Fracture Mechanics , 1985 .

[17]  Hong Hao,et al.  Numerical simulation of underground explosions , 1998 .

[18]  L. M. Taylor,et al.  Microcrack-induced damage accumulation in brittle rock under dynamic loading , 1986 .

[19]  Sumio Murakami,et al.  Constitutive and damage evolution equations of elastic-brittle materials based on irreversible thermodynamics , 1997 .

[20]  Donald R. Curran,et al.  Fragmentation of rock under dynamic loads , 1974 .

[21]  J. Ju,et al.  On energy-based coupled elastoplastic damage theories: Constitutive modeling and computational aspects , 1989 .

[22]  B. Steverding,et al.  The fracture penetration depth of stress pulses , 1976 .

[23]  B. M. Butcher,et al.  A criterion for the time dependence of dynamic fracture , 1968 .

[24]  G. Swoboda,et al.  Deformation behavior of ductile solids containing anisotropic damage , 1993 .

[25]  M. E. Kipp,et al.  Continuum modelling of explosive fracture in oil shale , 1980 .

[26]  R. L. Parrish,et al.  Development of a predictive capability for oil shale rubblization: Result of recent cratering experiments , 1984 .

[27]  J. Chaboche.  Continuum Damage Mechanics: Part I—General Concepts , 1988 .