IIW Recommendations for the HFMI Treatment

by Gary B. Marquis
IIW Recommendations for the HFMI Treatment
Author: Gary B. Marquis
Publisher: Springer
Total Pages: 44
Release: 2016-09-29
Genre: Technology & Engineering
ISBN: 9811025045
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This book of recommendations presents an overview of High Frequency Mechanical Impact (HFMI) techniques existing today in the market and their proper procedures, quality assurance measures and documentation. Due to differences in HFMI tools and the wide variety of potential applications, certain details of proper treatments and quantitative quality control measures are presented generally. An example of procedure specification as a quality assurance measure is given in the Appendix. Moreover, the book presents procedures for the fatigue life assessment of HFMI-improved welded joints based on nominal stress, structural hot spot stress and effective notch stress. It also considers the extra benefit that has been experimentally observed for HFMI-treated high-strength steels. The recommendations offer proposals on the effect of loading conditions like high mean stress fatigue cycles, variable amplitude loading and large amplitude/low cycle fatigue cycles. Special considerations for low stress concentration welded joints are also given. In order to demonstrate the use of the guideline, the book provides several fatigue assessment examples.

IIW Recommendations On Methods for Improving the Fatigue Strength of Welded Joints

by P J Haagensen
IIW Recommendations On Methods for Improving the Fatigue Strength of Welded Joints
Author: P J Haagensen
Publisher: Woodhead Publishing
Total Pages: 90
Release: 2013-01-25
Genre: Technology & Engineering
ISBN: 1782420657
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The weld toe is a primary source of fatigue cracking because of the severity of the stress concentration it produces. Weld toe improvement can increase the fatigue strength of new structures significantly. It can also be used to repair or upgrade existing structures. However, in practice there have been wide variations in the actual improvements in fatigue strength achieved. Based on an extensive testing programme organised by the IIW, this report reviews the main methods for weld toe improvement to increase fatigue strength: burr grinding, TIG dressing and hammer and needle peening. The report provides specifications for the practical use of each method, including equipment, weld preparation and operation. It also offers guidance on inspection, quality control and training as well as assessments of fatigue strength and thickness effects possible with each technique. IIW recommendations on methods for improving the fatigue strength of welded joints will allow a more consistent use of these methods and more predictable increases in fatigue strength. Provides specifications for the practical use of each weld toe method, including equipment, weld preparation and operation Offers guidance on inspection, quality control and training, as well as assessments of fatigue strength and thickness effects possible with each technique This report will allow a more consistent use of these methods and more predictable increases in fatigue strength

IIW Guidelines on Weld Quality in Relationship to Fatigue Strength

by Bertil Jonsson
IIW Guidelines on Weld Quality in Relationship to Fatigue Strength
Author: Bertil Jonsson
Publisher: Springer
Total Pages: 124
Release: 2016-04-13
Genre: Technology & Engineering
ISBN: 3319191985
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This book presents guidelines on quantitative and qualitative measures of the geometric features and imperfections of welds to ensure that it meets the fatigue strength requirements laid out in the recommendations of the IIW (International Institute of Welding). Welds that satisfy these quality criteria can be assessed in accordance with existing IIW recommendations based on nominal stress, structural stress, notch stress or linear fracture mechanics. Further, the book defines more restrictive acceptance criteria based on weld geometry features and imperfections with increased fatigue strength. Fatigue strength for these welds is defined as S-N curves expressed in terms of nominal applied stress or hot spot stress. Where appropriate, reference is made to existing quality systems for welds.In addition to the acceptance criteria and fatigue assessment curves, the book also provides guidance on their inspection and quality control. The successful implementation of these methods depends on adequate training for operators and inspectors alike. As such, the publication of the present IIW Recommendations is intended to encourage the production of appropriate training aids and guidelines for educating, training and certifying operators and inspectors.

IIW Recommendations for the Fatigue Assessment of Welded Structures By Notch Stress Analysis

by W Fricke
IIW Recommendations for the Fatigue Assessment of Welded Structures By Notch Stress Analysis
Author: W Fricke
Publisher: Woodhead Publishing
Total Pages: 76
Release: 2012-10-22
Genre: Technology & Engineering
ISBN: 085709856X
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The notch stress approach for fatigue assessment of welded joints is based on the highest elastic stress at the weld toe or root. In order to avoid arbitrary or infinite stress results, a rounded shape with a reference radius instead of the actual sharp toe or root is usually assumed. IIW recommendations for the fatigue assessment of welded structures by notch stress analysis reviews different proposals for reference radii together with associated S-N curves. Detailed recommendations are given for the numerical analysis of notch stress by the finite or boundary element method. Several aspects are discussed, such as the structural weakening by keyhole-shaped notches and the consideration of multiaxial stress states. Appropriate S-N curves are presented for the assessment of the fatigue strength of different materials. Finally, four examples illustrate the application of the approach as well as the variety of structures which can be analysed and the range of results that can be obtained from different models. Provides detailed recommendations for the number analysis of notch stress by the finite or boundary element method Discusses structural weakening by keyhole-shaped notches and the consideration of multiaxial stress states Provides four comprehensive examples, illustrating the variety of structures which can be analysed and the range of results that can be obtained from different models

Fatigue Design (ESIS 16)

by J. Solin
Fatigue Design (ESIS 16)
Author: J. Solin
Publisher: Wiley-Blackwell
Total Pages: 376
Release: 1993-03-02
Genre: Technology & Engineering
ISBN:
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A compilation of research in fatigue design, prediction, and assessment Fatigue Design is a collection of research presented at the 1993 International Symposium on Fatigue Design. Detailing the latest findings and most current research, this book features papers on a variety of pertinent topics, including the quantification of service load for fatigue life predictions, identification of stress states and failure modes, assessment of residual life in damaged components, and more. Special attention is paid to the need for simple and reliable prediction tools to help better ensure adequate strength at the design stage.

Structural Hot-Spot Stress Approach to Fatigue Analysis of Welded Components

by Erkki Niemi
Structural Hot-Spot Stress Approach to Fatigue Analysis of Welded Components
Author: Erkki Niemi
Publisher: Springer
Total Pages: 85
Release: 2017-08-28
Genre: Technology & Engineering
ISBN: 9811055688
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This book provides background and guidance on the use of the structural hot-spot stress approach to fatigue analysis. The book also offers Design S-N curves for use with the structural hot-spot stress for a range of weld details, and presents parametric formulas for calculating stress increases due to misalignment and structural discontinuities. Highlighting the extension to structures fabricated from plates and non-tubular sections. The structural hot-spot stress approach focuses on cases of potential fatigue cracking from the weld toe and it has been in use for many years in tubular joints. Following an explanation of the structural hot-spot stress, its definition and its relevance to fatigue, the book describes methods for its determination. It considers stress determination from both finite element analysis and strain gauge measurements, and emphasizes the use of finite element stress analysis, providing guidance on the choice of element type and size for use with either solid or shell elements. Lastly, it illustrates the use of the recommendations in four case studies involving the fatigue assessment of welded structures using the structural hot-spot stress

Recommendations for Fatigue Design of Welded Joints and Components

by A. F. Hobbacher
Recommendations for Fatigue Design of Welded Joints and Components
Author: A. F. Hobbacher
Publisher: Springer
Total Pages: 153
Release: 2015-12-23
Genre: Technology & Engineering
ISBN: 3319237578
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This book provides a basis for the design and analysis of welded components that are subjected to fluctuating forces, to avoid failure by fatigue. It is also a valuable resource for those on boards or commissions who are establishing fatigue design codes. For maximum benefit, readers should already have a working knowledge of the basics of fatigue and fracture mechanics. The purpose of designing a structure taking into consideration the limit state for fatigue damage is to ensure that the performance is satisfactory during the design life and that the survival probability is acceptable. The latter is achieved by the use of appropriate partial safety factors. This document has been prepared as the result of an initiative by Commissions XIII and XV of the International Institute of Welding (IIW).

Fatigue of Welded Structures

by Timothy Russell Gurney
Fatigue of Welded Structures
Author: Timothy Russell Gurney
Publisher: CUP Archive
Total Pages: 480
Release: 1979-12-20
Genre: Technology & Engineering
ISBN: 9780521225588
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