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Crack closure

About: Crack closure is a research topic. Over the lifetime, 28157 publications have been published within this topic receiving 588158 citations.


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Journal ArticleDOI
TL;DR: In this article, a path independent J integral for a crack in a residual stress field is obtained and the modified J is equivalent to the stress intensity factor, K, under small scale yielding conditions and provides the intensity of the near crack tip stresses under elastic-plastic conditions.
Abstract: The standard definition of the J integral leads to a path dependent value in the presence of a residual stress field, and this gives rise to numerical difficulties in numerical modelling of fracture problems when residual stresses are significant. In this work, a path independent J definition for a crack in a residual stress field is obtained. A number of crack geometries containing residual stresses have been analysed using the finite element method and the results demonstrate that the modified J shows good path-independence which is maintained under a combination of residual stress and mechanical loading. It is also shown that the modified J is equivalent to the stress intensity factor, K, under small scale yielding conditions and provides the intensity of the near crack tip stresses under elastic-plastic conditions. The paper also discusses two issues linked to the numerical modelling of residual stress crack problems-the introduction of a residual stress field into a finite element model and the introduction of a crack into a residual stress field.

134 citations

Journal ArticleDOI
TL;DR: It is shown that after the critical fracture load is reached, the crack speed jumps from zero to approximately 2 km/sec, indicating that crack motion at lower speeds is forbidden, contradicts classical continuum fracture theories predicting a continuously increasing crack speed with increasing load.
Abstract: Fracture experiments of single silicon crystals reveal that after the critical fracture load is reached, the crack speed jumps from zero to [approximate]2 km/sec, indicating that crack motion at lower speeds is forbidden. This contradicts classical continuum fracture theories predicting a continuously increasing crack speed with increasing load. Here we show that this threshold crack speed may be due to a localized phase transformation of the silicon lattice from 6-membered rings to a 5–7 double ring at the crack tip.

134 citations

Book
30 Nov 1990
TL;DR: In this paper, the authors proposed an energy balance model for a semi-infinite crack and showed that the model can be used to detect cracks in bending plates and shells in concrete.
Abstract: 1. Introductory chapter.- 1.1. Conventional failure criteria.- 1.2. Characteristic brittle failures.- 1.3. Griffith's work.- 1.4. Fracture mechanics.- References.- 2. Linear elastic stress field in cracked bodies.- 2.1. Introduction.- 2.2. Crack deformation modes and basic concepts.- 2.3. Eigenfunction expansion method for a semi-infinite crack.- 2.4. Westergaard method.- 2.5. Singular stress and displacement fields.- 2.6. Method of complex potentials.- 2.7. Numerical methods.- 2.8. Experimental methods.- 2.9. Three-dimensional crack problems.- 2.10. Cracks in bending plates and shells.- References.- 3. Elastic-plastic stress field in cracked bodies.- 3.1. Introduction.- 3.2. Approximate determination of the crack-tip plastic zone.- 3.3. Small-scale yielding solution for antiplane mode.- 3.4. Complete solution for antiplane mode.- 3.5. Irwin's model.- 3.6. Dugdale's model.- 3.7. Singular solution for a work-hardening material.- 3.8. Numerical solutions.- References.- 4. Crack growth based on energy balance.- 4.1. Introduction.- 4.2. Energy balance during crack growth.- 4.3. Griffith theory.- 4.4. Graphical representation of the energy balance equation.- 4.5. Equivalence between strain energy release rate and stress intensity factor.- 4.6. Compliance.- 4.7. Critical stress intensity factor fracture criterion.- 4.8. Experimental determination of KIc.- 4.9. Crack stability.- 4.10. Crack growth resistance curve (R-curve) method.- 4.11. Mixed-mode crack propagation.- References.- 5. J-Integral and crack opening displacement fracture criteria.- 5.1. Introduction.- 5.2. Path-independent integrals.- 5.3. J-integral.- 5.4. Relationship between the J-integral and potential energy.- 5.5. J-integral fracture criterion.- 5.6. Experimental determination of the J-integral.- 5.7. Stable crack growth studied by the J-integral.- 5.8. Mixed-mode crack growth.- 5.9. Crack opening displacement (COD) fracture criterion.- References.- 6. Strain energy density failure criterion.- 6.1. Introduction.- 6.2. Volume strain energy density.- 6.3. Basic hypotheses.- 6.4. Two-dimensional linear elastic crack problems.- 6.5. Uniaxial extension of an inclined crack.- 6.6. Three-dimensional linear elastic crack problems.- 6.7. Bending of cracked plates.- 6.8. Ductile fracture.- 6.9. Failure initiation in bodies without pre-existing cracks.- 6.10. Other criteria based on energy density.- References.- 7. Dynamic fracture.- 7.1. Introduction.- 7.2. Mott's model.- 7.3. Stress field around a rapidly propagating crack.- 7.4. Strain energy release rate.- 7.5. Transient response of cracks to impact loads.- 7.6. Standing plane waves interacting with a crack.- 7.7. Crack branching.- 7.8. Crack arrest.- 7.9. Experimental determination of crack velocity and dynamic stress intensity factor.- References.- 8. Fatigue and environment-assisted fracture.- 8.1. Introduction.- 8.2. Fatigue crack propagation laws.- 8.3. Fatigue life calculations.- 8.4. Variable amplitude loading.- 8.5. Mixed-mode fatigue crack propagation.- 8.6. Nonlinear fatigue analysis based on the strain energy density theory.- 8.7. Environment-assisted fracture.- References.- 9. Engineering applications.- 9.1. Introduction.- 9.2. Fracture mechanics design philosophy.- 9.3. Design example problems.- 9.4. Fiber-reinforced composites.- 9.5. Concrete.- 9.6. Crack detection methods.- References.- Author Index.

134 citations

Journal ArticleDOI
TL;DR: In this paper, a bilinear equation of motion for each vibration mode of a simply supported beam is formulated by a Galerkin procedure, and the dynamic response of this equation under a concentrated forcing excitation is calculated through a numerical analysis.

134 citations

Journal ArticleDOI
TL;DR: In this paper, an overview is given about theories, experiments and simulations of cracks and crack growth under Mixed Mode loading. And the theoretical and experimentally results are compared with respect of the practical use of the described concepts and theories.

134 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023219
2022536
2021143
2020154
2019172
2018244