Numerical Assessments of Cracks in Elastic-Plastic Materials

ISBN-13: 9783540433361 / Angielski / Twarda / 2002 / 311 str.

Harm Derksen; Huang Yuan

Opis

In this book a systematic discussion of crack problems in elastic-plastic materials is presented. The state of the art in fracture mechanics research and assessment of cracks is documented, with the help of analytic, asymptotic methods as well as finite element computations. After a brief introduction to fracture mechanics, the two-parameter concept for stationary cracks is studied in addition to the issues in three-dimensional crack fields under coupling with strong out-of-plane effects. Cracks along interfaces and crack growth problems under mixed mode conditions are also treated. A systematic study of stress singularities for different notches is accompanied by detailed finite element computations.

Spis treści

1. Introduction.- 2. Cracks under stationary conditions.- 2.1 Higher-order solutions for pressure-sensitive materials.- 2.1.1 Governing equations.- 2.1.2 Plane strain fields.- 2.1.3 Plane stress fields.- 2.1.4 Two-parameter characterization based on higher-order solutions.- 2.2 Two-parameter characterizations for engineering materials.- 2.2.1 Small-scale yielding fields.- 2.2.2 Plane strain fields under general yielding.- 2.3 Effects of biaxial loads to plane stress cracks.- 2.3.1 Small-scale yielding fields.- 2.3.2 Finite-cracked geometries.- 2.4 Three-dimensional crack front fields.- 2.4.1 Modified boundary layer formulations.- 2.4.2 Finite-cracked specimens.- 2.5 Remarks.- 3. Cracks under thermal-mechanical loading conditions.- 3.1 Characterization of cracks under high temperature gradients.- 3.1.1 J controlled zone around the crack tip.- 3.1.2 J ? Q characterization.- 3.1.3 Plane stress crack tip fields.- 3.2 Scaling of temperature-induced material inhomogeity.- 3.2.1 Crack tip parameters.- 3.2.2 Scaling of temperature gradients.- 3.3 Effects of transient thermal loading.- 3.3.1 Finite element modeling.- 3.3.2 Numerical results.- 3.4 Remarks.- 4. Interface cracks.- 4.1 Stationary interface crack tip fields.- 4.1.1 Cracks under the J2 plasticity theory.- 4.1.2 Cracks in pressure-sensitive materials.- 4.1.3 General elastic-plastic interface cracks.- 4.2 Quasi-static crack growth.- 4.2.1 Anti-plane cracks.- 4.2.2 In-plane interface cracks.- 4.3 Dynamic interface crack growth.- 4.3.1 Anti-plane shear mode III cracks.- 4.3.2 Plane strain interface cracks.- 4.4 Remarks.- 5. Mixed mode crack propagation.- 5.1 Static crack growth under combined mode I and III conditions.- 5.1.1 Mode III perturbation solutions.- 5.1.2 Mode I perturbation solutions.- 5.2 Dynamic crack growth under combined mode I and III conditions.- 5.2.1 Formulation of a perturbation solution.- 5.2.2 Mode III perturbation solutions.- 5.2.3 Mode I perturbation solutions.- 5.3 Remarks.- 6. Assessment of apex-V notches.- 6.1 Higher-order solutions for power-law hardening materials.- 6.1.1 Plan strain notch-tip fields.- 6.1.2 Near-tip fields for a notch lying along an interface.- 6.1.3 Plane stress notch-tip fields.- 6.1.4 Effects of the notch bluntness.- 6.2 Notches in pressure-sensitive materials.- 6.2.1 Plane strain tip fields.- 6.2.2 Plane stress tip fields.- 6.3 Remarks.- References.

Blurb

In this book a systematic discussion of crack problems in elastic-plastic materials is presented. The state of the art in fracture mechanics research and assessment of cracks is documented with the help of analytic, asymptotic methods as well as finite element computations. After a brief introduction to fracture mechanics the two-parameter concept for stationary cracks is studied as well as the issues in three-dimensional crack fields under coupling with strong out-of-plane effects. Cracks along interfaces are treated as well as crack growth problems under mixed mode conditions. A systematic study of stress singularities for different notches is accompanied by detailed finite element computations.