Kiev: PWI, 2005. 266 pp. - Format 165x235 mm. Softback, ISBN 966-8072-02-9, $90.
In this manuscript, the idea of the fitness-for-purpose concept is used to improve strength calculations of welded joints with crack-like imperfections caused by structural or technological factors, having fillet, spot, slot and butt welds.
The above welded joints do not usually cause problems for structures of relatively ductile materials with small-to-medium thicknesses of component sections, and operating under predominantly static loading. However, the use of new structural materials, especially high-strength steels and aluminium alloys, etc., large cross sections of structural elements, and loading with alternate loads, requires a certain caution to be taken.
Performing strength calculations based on the fitness-for-purpose criterion for the joints encountered in general-purpose structures allows ensuring the requirements concerning the service lifetime. As shown by the authors, a successful implementation of the mentioned concept for general-purpose welded joints and for wide range of users is possible only when it is based on the use of corresponding computer systems with friendly user interface.
CONTENTS
Introduction 5
Chapter 1 Characteristics of Welded Joints with Crack-Like Imperfections 7
1.1 Geometry Characteristics of Welded Joints with Crack-Like Imperfections 7
1.2 Non-Uniformity in Mechanical Properties of Welded Joints 11
References to Chapter 1 15
Chapter 2 Stresses and Strains in Welded Joints in the Vicinity of Crack-Like Imperfections 17
2.1 Fundamentals of Stresses and Strains 17
2.2 Summary of Welding Residual Stresses 20
2.3 Stresses in Welded Joints Caused by External Loading 32
2.3.1 Joints with Butt Welds 32
2.3.2 Joints with Fillet Welds 34
2.3.3 Lap Joints with Spot and Plug Welds 49
2.3.4 Peculiarities of Stresses and Strains in the Vicinity of Crack-Like Imperfections 53
References to Chapter 2 60
Chapter 3 Criteria of Ultimate State in Welded Joints with Crack-Like Imperfections 61
3.1 Ductile-Brittle Failures at Static Loading 61
3.1.1 Failures Caused by Neck Formation - Plastic Instability 62
3.1.2 Failures without Obvious Neck Formation 67
3.1.3 Fractures Caused by Crack-Like Stress Concentrations 74
3.2 Criteria of Ultimate States in Welded Joints at Cyclic Loading 87
3.2.1 General Information of Fatigue Failure Initiation in Welded Joints 88
3.2.2 Selection of Criteria for Evaluation of Fatigue Crack Initiation Cycles in Welded Joints at Low-Cycle Fatigue 94
3.2.3 Selection of Criteria for Calculation of Fatigue Crack Initiation Cycles in Welded Joints at High-Cycle Fatigue 98
3.2.4 Selection of Numerical Schemes for Assessment of Fatigue Crack Propagation Life in Welded Joints 106
3.2.5 Irregular Cyclic Loading 115
3.3 Accounting for the Effect of Random Variation of Input Parameters 120
References to Chapter 3 121
Chapter 4 Application of the Developed Approaches in Engineering Practice 125
4.1 Architecture of the Computer System for Strength
Calculation of Welded Joints 125
4.2 Software System for Strength Calculation of Joints with Fillet Welds 131
4.3 Cruciform Joints 137
4.4 T-Joints with Two-Sided Fillet Welds 145
4.5 T-Joints with One-Sided Fillet Welds with Incomplete Penetration 152
4.6 Lap Joints with Fillet Welds 162
4.7 Reliability of Calculations and Dimensions of Fillet Welds in Various Welded Parts 167
4.8 Effect of Welding Residual Stresses on Ultimate Loads and Calculated Size of Load-Carrying Fillet Welds in Various Joints 170
4.9 Joints with Butt Welds and Crack-Like Stress Concentrations 175
4.10 Joints with Spot Welds 187
4.11 Welded Joints Operating at Elevated and High Temperatures 193
4.12 Comments on the Calculation of Load-Carrying Capacity of Welded Joints in Sections away from Stress Concentration 201
References to Chapter 4 211
Chapter 5 Assessment of Admissible Defects in Welded Joints in Service Loading 215
5.1 Schematic Presentation of Defects in Welded Joints 215
5.1.1 Single Sub-Surface Defects 215
5.1.2 Pair Sub-Surface Defects 217
5.1.3 Multiple Sub-Surface Defects 218
5.1.4 Single Surface Defects 219
5.1.5 Pair- and Multiple Surface Defects 222
5.1.6 Schematization of Through-the-Thickness Defects 223
5.1.7 Schematization of Pair- and Multiple Defects of Different Types 224
5.2 Calculations of Stress Intensity Factors for Equivalent Cracks 225
5.2.1 Embedded Cracks 226
5.2.2 Surface Semi-Elliptical Cracks 229
5.2.3 Through-the-Thickness Cracks 234
5.3 Examples of Using of the Developed Procedures for Calculation of Admissible Defects in Welded Joints 235
5.3.1 Failures of Austenitic Stainless Steel Pipelines at the Chernobyl Nuclear Power Plant Induced by Intergranular Stress Corrosion Cracking in the Zone of Butt Welded Joints 235
5.3.2 Assessment of the Effect of Irradiation Embrittlement of Welds on Safe Operation of a WWER-Type Reactor Pressure Vessel 256
References to Chapter 5 265
