Author: J. F. Throop
Publisher: ASTM International
ISBN: 9780803107113
Category : Technology & Engineering
Languages : en
Pages : 252

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Book Description

Author: JF. Throop
Publisher:
ISBN:
Category : Crack propagation
Languages : en
Pages : 4

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Book Description
In this paper it is reemphasized that the effect of residual stress in fatigue is analogous to but not the same as the mean stress effect from applied loads. By including a residual stress term in the stress intensity factor range of the fatigue crack propagation rate equation, one is permitted to include the residual stress in calculations of fatigue life estimates. Using crack shape factors calculated for given aspect ratios of surface flaws and integrating the fatigue crack growth rate da/dN, one obtains an equation for the applied stress-cycles to failure S-N curve that includes the residual stress effect on fatigue performance. In this process of calculation that fact that compressive residual stress has a much stronger influence on fatigue life than tensile residual stress is revealed, mainly because the former decreases the stress intensity factor range and increases the critical crack size while the latter only decreases the critical crack size. A numerical solution of an example illustrates an application of these concepts.

Author:
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 256

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Book Description

Author: Michael R. Mitchell
Publisher: ASTM International
ISBN: 0803144725
Category : Fracture mechanics
Languages : en
Pages : 164

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Book Description
"Eleven peer-reviewed papers, written by experts in their field, provide an understanding of residual stresses, fatigue crack growth, fatigue lifetime predictions, and their effect on structural integrity. Residual stresses can be present due to processing and manufacturing of materials and structures, so it is imperative to understand how and why they can influence the test data that we used in structural design methodologies. Residual stresses may also be intentionally engineered into structures in attempts to improve fatigue life, and it is equally important that designers understand how to account for these potential effects on fatigue life."--Publisher's website.

Author: Joseph F. Throop
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description
It is re-emphasized here that the effect of residual stress in fatigue is analogous to but not the same as the mean stress effect from applied loads. The inclusion of a residual stress term in the stress intensity factor range of the fatigue crack propagation rate equation permits one to use the residual stress in calculations of fatigue life estimates. Using crack shape factors calculated for given aspect ratios of surface flaws and integrating da/dN, one obtains an equation for the S-N curve which includes the residual stress effect on fatigue performance. This process of calculation reveals that compressive residual stress has a much stronger influence on fatigue life than tensile residual stress does, mainly because the former decreases the stress intensity factor range and increases the critical crack size while the latter only decreases the critical crack size. Numerical solution of an example illustrates an application of these concepts.

Author: Robert L. Champoux
Publisher: ASTM International
ISBN: 0803111959
Category : Fatigue strength (Engineering materials).
Languages : en
Pages : 141

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Book Description

Author: Anastasius Youtsos
Publisher: Springer Science & Business Media
ISBN: 1402053290
Category : Technology & Engineering
Languages : en
Pages : 229

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Book Description
The contents of this book have been grouped into three topic areas covering theoretical /numerical and experimental analyses of residual stress and its effects on fatigue and fracture. It details recent advances on its title topics by leading European experts and contains theoretical/numerical studies of high value backed by sound experimental data. It also provides experimental studies based on novel and verifiable testing methods.

Author: Kenneth L. Jerina
Publisher: ASTM International
ISBN: 0803126174
Category : Technology & Engineering
Languages : en
Pages : 480

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Book Description

Author: John H. Underwood
Publisher: ASTM International
ISBN: 0803124104
Category : Fracture mechanics
Languages : en
Pages : 697

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Book Description

Author: Christopher James Lammi
Publisher:
ISBN:
Category :
Languages : en
Pages : 230

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Book Description
Abstract: Residual stresses are a common and often undesired result of material processing, introduced through non-linear deformation and/or phase transformation of material under mechanical or thermo-mechanical loading. These macro stresses alter mechanical properties and the intrinsic fatigue crack growth characteristics of the material. Residual stress artifacts can introduce inconsistencies and significant errors when the true material behavior is needed for material development and optimization and for structural component design. The effects of quenching residual stresses on fatigue crack propagation behavior of various materials were investigated. In parallel, residual stresses similar in magnitude and distribution with the quenching residual stresses were generated using mechanical processes to decouple the effects of residual stresses from microstructural effects. Mechanical residual stress distributions predicted by 3D elastic-plastic finite element analysis showed good agreement with the stresses measured on fatigue crack growth testing specimens using fracture mechanics approaches. Crack propagation characteristics in fields with low and high residual stresses were studied using optical and scanning electron microscopy, and the effects of residual stress on crack path behavior were assessed. An original residual stress analytical correction to fatigue crack growth data was developed, compared to existing corrective methodologies, and validated using residual stress free data. Overall, the work provides tools to understand, control, and correct the effects of processing residual stresses on fatigue crack growth for accurate fatigue critical design and life predictions.