Dassault Systemes Inc. Modeling Fracture and Failure with Abaqus

393 Pages·16.612 MB·English

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Modeling Fracture and Failure with Abaqus @
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About this Course
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Course objectives r c
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Upon completion of this course you will be able to: s
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Use proper modeling techniques for capturing crack-tip singularities in fracture mechanics problems
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Use Abaqus/CAE to create meshes appropriate for fracture studies e s
Calculate stress intensity factors and contour integrals around a crack tip R u
Simulate material damage and failure q
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Simulate crack growth using cohesive behavior, VCCT, and XFEM a
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©stelumaèstssayDS TarS giemtueladt ea luowd-iceynclce efa tigue crack growth y Sci nz Ab
| m Simulation Analysts b .
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This course is recommended for engineers with experience using Abaqus n
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Day 1
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Lecture 1 Basic Concepts of Fracture Mechanics F s
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Lecture 2 Modeling Cracks
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Lecture 3 Fracture Analysis a q
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Workshop 1 Crack in a Three-point Bend Specimen s b
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Day 2 .
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Lecture 4 Material Failure and Wear r c
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Lecture 5 Element-based Cohesive Behavior
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Workshop 3 Crack Growth in a Three-point Bend Specimen using Cohesive Connections (Part 1) R u
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Workshop 4 Crack Growth in a Helicopter Airframe Component using Cohesive Elements a
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Day 3
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Lecture 7 Virtual Crack Closure Technology (VCCT) F s
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Workshop 5 Crack Growth in a Three-point Bend Specimen using VCCT
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Lecture 8 Low-cycle Fatigue a q
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Lecture 9 Mesh-independent Fracture Modeling (XFEM) s b
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Legal Notices .
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The Abaqus Software described in this documentation is available only under license from Dassault r c
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Systèmes and its subsidiary and may be used or reproduced only in accordance with the terms of such s
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license.
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This documentation and the software described in this documentation are subject to change without e s
prior notice. R u
Dassault Systèmes and its subsidiaries shall not be responsible for the consequences of any errors or q
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omissions that may appear in this documentation. a
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owners. For additional information concerning trademarks, copyrights, and licenses, see the Legal u
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Notices in the Abaqus 6.12 Release Notes and the notices at:
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http://www.3ds.com/products/simulia/portfolio/product-os-commercial-programs. a c
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Revision Status
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Lecture 1 5/12 Updated for 6.12
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Lecture 2 5/12 Updated for 6.12 r u
Lecture 3 5/12 Updated for 6.12 a q
Lecture 4 5/12 Updated for 6.12 e a
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Lecture 5 5/12 Updated for 6.12
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Workshop 3 5/12 Updated for 6.12 y o
Workshop 4 5/12 Updated for 6.12 b i
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Workshop 6 5/12 Updated for 6.12 s @
Workshop 7 5/12 Updated for 6.12 u
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L1.1 .
Lesson 1: Basic Concepts of Fracture Mechanics p n
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Lesson content: F s
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Overview c s
Introduction r u
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Fracture Mechanisms
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Linear Elastic Fracture Mechanics
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Small Scale Yielding e
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Fatigue b i
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Overview .
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L1.3 .
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Introduction
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Fracture mechanics is the field of solid mechanics that deals with the behavior of cracked bodies subjected to F s
stresses and strains. @
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These can arise from primary applied loads or secondary self-equilibrating stress fields (e.g., residual c s
stresses). r u
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The objective of fracture mechanics is to characterize the local deformation around a crack tip in terms s
of the asymptotic field around the crack tip scaled by parameters that are a function of the loading and al u
global geometry. n q
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Fracture Mechanisms (1/4) .
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For engineering materials, such as metals, r c
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Brittle fracture
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Cracks spread very rapidly with little or n a
no plastic deformation. o
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Three stages: void nucleation, growth, u
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The crack moves slowly and is a c
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The crack typically will not grow unless s
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L1.5 .
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Fracture Mechanisms (2/4)
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Brittle fracture in polycrystalline materials displays either cleavage (transgranular) or intergranular F s
fracture. @
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This depends upon whether the grain boundaries are stronger or weaker than the grains . c s
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Cleavage fracture
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Fracture Mechanisms (3/4) .
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Ductile fracture has a dimpled, cup-and-cone fracture appearance . r c
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Ductile fracture surfaces have larger necking regions and an overall rougher appearance than a
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brittle fracture surface.
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L1.7 .
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Fracture Mechanisms (4/4)
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Fracture process zone F s
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The fracture process zone is the region around the crack tip where dislocation motions, material
damage, etc. occur. c s
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It is a region of nonlinear deformation. e a
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sem The fracture process zone size is characterized by Re A
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Linear Elastic Fracture Mechanics (1/10) .
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Fracture modes r c
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Linear Elastic Fracture Mechanics (LEFM)
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considers three distinct fracture modes: Modes
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I, II, and III
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These encompass all possible ways a crack tip n a
can deform. o
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