Recommendations for Fatigue Design of Welded Joints and Components (IIW Collection)

Preface
Contents
List of Figures
List of Tables
1 General
	1.1 Introduction
	1.2 Scope and Limitations
	1.3 Definitions
	1.4 Symbols
		1.4.1 Variables
		1.4.2 Subscripts
	1.5 Basic Principles
	1.6 Necessity of Fatigue Assessment
	1.7 Application of the Document
	References
2 Fatigue Actions (Loading)
	2.1 Basic Principles
		2.1.1 Determination of Fatigue Actions (Loading)
		2.1.2 Stress Range
		2.1.3 Types of Stress Concentrations and Notch Effects
	2.2 Determination of Stresses and Stress Intensity Factors
		2.2.1 Definition of Stress Components
		2.2.2 Nominal Stress
		2.2.3 Structural Hot Spot Stress
		2.2.4 Notch Stress
		2.2.5 Stress Intensity Factors
	2.3 Stress History
		2.3.1 General
		2.3.2 Cycle Counting Methods
		2.3.3 Cumulative Frequency Diagram (Stress Spectrum)
	References
3 Fatigue Resistance
	3.1 Basic Principles
	3.2 Fatigue Resistance of Classified Structural Details
	3.3 Fatigue Resistance Assessed on the Basis of Structural Hot Spot Stress
		3.3.1 Fatigue Resistance Using Design S-N Curve
		3.3.2 Fatigue Resistance Using a Reference Detail
	3.4 Fatigue Resistance Assessed on the Basis of Notch Stress
		3.4.1 Steel
		3.4.2 Aluminium
	3.5 Fatigue Strength Modifications
		3.5.1 Stress Ratio
		3.5.2 Wall Thickness
		3.5.3 Improvement Techniques
		3.5.4 Effect of Elevated Temperatures
		3.5.5 Effect of Corrosion
	3.6 Fatigue Resistance Assessed on the Basis of Crack Propagation Analysis
		3.6.1 Steel
		3.6.2 Aluminium
		3.6.3 Correlation of Fracture Mechanics to Other Verification Methods
	3.7 Fatigue Resistance Determination by Testing
		3.7.1 General Considerations
		3.7.2 S-N Curve Determination by Testing
		3.7.3 Crack Propagation Curves Determination by Testing
	3.8 Fatigue Resistance of Joints with Weld Imperfections
		3.8.1 General
		3.8.2 Misalignment
		3.8.3 Undercut
		3.8.4 Porosity and Inclusions
		3.8.5 Crack-Like Imperfections
	References
4 Fatigue Assessment
	4.1 General Principles
	4.2 Fatigue Assessment Using S-N Curves
		4.2.1 Main Principles
		4.2.2 Constant Amplitudes
		4.2.3 Variable Amplitudes
	4.3 Fatigue Assessment by Crack Propagation Calculation
		4.3.1 Main Principle
		4.3.2 General Procedure
		4.3.3 Calculation of Crack Propagation
		4.3.4 Variable Amplitude Loading
	4.4 Fatigue Assessment on the Basis of Service Testing
		4.4.1 General
		4.4.2 Acceptance Criteria
		4.4.3 Safe Life Assessment
		4.4.4 Fail-Safe Assessment
		4.4.5 Damage Tolerant Assessment
	References
5 Safety Considerations
	5.1 Basic Principles
	5.2 Fatigue Design Strategies
		5.2.1 Infinite Life Design
		5.2.2 Safe Life Design
		5.2.3 Fail-Safe Design
		5.2.4 Damage Tolerant Design
	5.3 Partial Safety Factors
	5.4 Quality Assurance
	5.5 Repair of Components
	References
6 Appendices
	6.1 Loading History
		6.1.1 Markov Transition Matrix
		6.1.2 “Rainflow” or “Reservoir” Counting Method
	6.2 Fracture Mechanics
		6.2.1 Rapid Calculation of Stress Intensity Factors
		6.2.2 Dimensions of Cracks
		6.2.3 Interaction of Cracks
		6.2.4 Formulae for Stress Intensity Factors
		6.2.5 Stress Distribution at a Weld Toe
	6.3 Formulae for Misalignment
	6.4 Statistical Considerations on Safety
		6.4.1 Statistics for Deriving Fatigue Test Results
		6.4.2 Statistical Evaluation of Results from Component Testing
		6.4.3 Statistical Evaluation of Results from Component Testing
	6.5 Fatigue Resistance of ISO 5817 Quality
	6.6 Application Examples
		6.6.1 Fatigue Assessment of a Structural Detail
		6.6.2 Fracture Mechanics Crack Propagation
		6.6.3 Fracture Mechanics by Weight Function
		6.6.4 Example for Basic Evaluation of a Data Set
	6.7 Verification of Log-Normal Distribution
		6.7.1 Calculation Table
		6.7.2 Henry Graph
		6.7.3 Criteria Parameters
		6.7.4 Rejection Criteria
	6.8 Estimation of Kmat from Charpy-V-Notch Data
	References