Results 221 to 230 of about 24,682 (265)

Constitutive Inequalities for the Damage of Elastic-Brittle Materials

Materials Science Forum, 2011
Starting from the requirement that the principle of determinism be satisfied, two constitutive inequalities are derived for one-dimensional strain- and stress-based continuum damage models. The one-dimensional constitutive inequality corresponding to the strain-based formulation turns out to be much less restrictive than the one associated to the ...
He, Qi-Chang, Zhou, J.Z.
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A theory of damage in brittle materials

Engineering Fracture Mechanics, 1990
Abstract The present paper addresses the geometric representation of damage in brittle solids, its equation of evolution and its incorporation in the constitutive equation. The concept of a damage coordinate is introduced and a thermodynamic derivation of the evolution equation follows. A continuum damage theory ensues.
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Dynamic damage evolution in brittle solids

Mechanics of Materials, 1992
Abstract For brittle solids containing preexisting microflaws, a two-dimensional model is developed to simulate dynamic damage evolution in uniaxial compression. Frictional, and rate-dependent and rate-independent plastic constitutive relations are considered to describe the deformation of preexisting microflaws.
H. Deng, S. Nemat-Nasser
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Micromechanics of Damage in Brittle Solids

2003
This chapter deals with microcrack damage models of brittle deformation in rocklike solids under quasi-static loading. Starting with basic mechanisms of microcrack growth under tension and compression, non-linear stress-strain relationships are derived within the thermodynamic framework with microstructural internal variables. Illustrative examples are
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A microcrack damage model for brittle materials

International Journal of Solids and Structures, 1993
Abstract A damage model for brittle materials subject to arbitrary stress is developed. By considering dilute distributions of flat microcracks, self-similarly propagating in a linear elastic matrix, constitutive equations are obtained taking into account both stress- and damage-induced anisotropy.
GAMBAROTTA, LUIGI, LAGOMARSINO, SERGIO
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The nature of machining damage in brittle materials

Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1983
Abstract The micromechanics of failure emanating from machining-induced cracks in brittle materials is investigated. In situ monitoring of crack response during breaking tests (with use of acoustic wave scattering), strength measurements and post-failure fractography all indicate that the crack response is dominated by residual ...
D. B. Marshall, Anthony Glyn Evans, B. T. Khuri Yakub, J. W. Tien, G. S. Kino   +4 more
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Continuous Damage of Brittle Solids

1987
Some elastic solids fail not through macro — fracture or plastic flow, but rather through growth of micro — defects. Modelling of such processes occurs through theories of continuous damage mechanics. Thermodynamic aspects of one such theory are discussed in this paper, focussing on limitations of admissible processes, energy dissipation in a loading —
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Surface damage in brittle materials

2001
It has long been recognized that structural modifications of the surface layers of materials induced by mechanical processing may affect adversely the performance of engineering components in service. Traditionally, the most deleterious changes have manifested themselves as residual stresses that lower the fatigue life or distort the shape of metallic ...
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Brittle Damage Mechanics of Rock Mass

2010
In this chapter, special aspects of brittle damage mechanics are considered, related to the various frameworks by which the behavior of a brittle damaged material can be postulated, still considering the damaged medium as a global continuum. The basic framework of CDM is recalled, stressing the concepts of effective stress and the ways of introducing ...
Wohua Zhang, Yuanqiang Cai
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Brittle Fracture and Damage of Brittle Materials and Composites Statistical-Probabilistic Approaches

2016
Flaws are the principal source of fracture in many materials, whether brittle or ductile, whether nearly homogeneous or composite. They are introduced during either fabrication or surface preparation or during exposure to aggressive environments (e. g. oxidation, shocks). The critical flaws act as stress concentrators and initiate cracks that propagate
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