Preface	6
	Contents	9
	Abstract	13
	1 Introduction	14
	1.1 General	14
	1.2 Safety Aspects	16
	References	16
	2 The Structural Hot-Spot Stress Approach to Fatigue Analysis	18
	2.1 Field of Application	18
	2.2 Types of Hot Spot	19
	2.3 Definition of the Structural Stress at a Type “a” Hot-Spot	20
	2.4 Use of Stress Concentration Factors	22
	2.4.1 Modified Nominal Stress	22
	2.4.2 Structural Stress Concentration Factors, Ks	22
	2.4.3 Stress Magnification Factor Due to Misalignment Km	23
	2.5 Effect of Component Size on the Fatigue Resistance	25
	References	25
	3 Experimental Determination of the Structural Hot-Spot Stress	26
	3.1 General	26
	3.2 Type “a” Hot Spots	26
	3.3 Type “b” Hot Spots	28
	References	29
	4 Structural Hot-Spot Stress Determination Using Finite Element Analysis	30
	4.1 General	30
	4.2 Choice of Element Type	31
	4.3 Methods for Determination of Structural Hot-Spot Stress	32
	4.3.1 Determination of the Structural Stress at the Weld Toe Using Through-Thickness Linearization	33
	4.3.2 Determination of the Structural Stress at the Weld Toe Using Surface Stress Extrapolation	34
	4.3.3 Determination of the Structural Stress at a Single Point Close to the Weld Toe	38
	4.4 Use of Relatively Coarse Element Meshes	39
	4.4.1 Solid Element Modelling	39
	4.4.2 Thin Shell (or Plate) Element Modelling	40
	4.4.3 Hot-Spot Stress Extrapolation	40
	4.5 Use of Relatively Fine Element Meshes	41
	4.5.1 Solid Element Modelling	41
	4.5.2 Thin Shell (or Plate) Element Modelling	42
	4.5.3 Hot-Spot Stress Extrapolation	42
	4.6 Modelling Fillet Welds in Shell Element Models	42
	References	43
	5 Parametric Formulae	45
	5.1 Misalignment	45
	5.1.1 Axial Misalignment Between Flat Plates of Equal Thickness Under Axial Loading	45
	5.1.2 Axial Misalignment Between Flat Plates of Differing Thickness Under Axial Loading	46
	5.1.3 Axial Misalignment Between Tubes or Pipes Under Axial Loading	46
	5.1.4 Axial Misalignment at Joints in Pressurized Cylindrical Shells with Thickness Change	47
	5.1.5 Angular Misalignment Between Flat Plates of Equal Thickness Under Axial Loading	47
	5.1.6 Angular Misalignment at Longitudinal Joints in Pressurized Cylindrical Shells	48
	5.1.7 Ovality in Pressurized Cylindrical Pipes and Shells	49
	5.2 Structural Discontinuities	49
	References	50
	6 Structural Hot-Spot S-N Curves	51
	6.1 General Principles	51
	6.2 Recommended S-N Curves for the Conventional Structural Hot-Spot Stress Approach	54
	6.2.1 Hot-Spot S-N Curves	54
	6.2.2 Hot-Spot S-N Curves for Tubular Joints in Steel	55
	6.3 Recommended S-N Curves for the Other Structural Stress Approaches	55
	6.3.1 Structural Stress Approach According to Dong	55
	6.3.2 Structural Stress Approach According to Xiao and Yamada	56
	6.3.3 Structural Stress Approach According to Haibach	56
	References	56
	7 Case Study 1: Box Beam of a Railway Wagon	58
	7.1 Introduction	58
	7.2 Materials and Methods	58
	7.2.1 Description of the Structure	58
	7.2.2 Angular Misalignment in the Web	58
	7.2.3 Strain Gauge Measurements	59
	7.2.4 Structural Hot-Spot Stress Determination	60
	7.2.5 S-N Curve	61
	7.2.6 Partial Safety Factors	62
	7.3 Results	62
	7.3.1 Stress Concentration Factor, Ks	62
	7.3.2 Results for a Perfectly Straight Web	62
	7.3.3 Effective Magnification Factor, Km	63
	7.3.4 Results for a Web with Angular Misalignment	64
	7.4 Discussion and Conclusions	64
	8 Case Study 2: Hatch Corner Design for Container Ships	66
	8.1 Introduction	66
	8.2 Materials and Methods	66
	8.2.1 Description of the Structure	66
	8.2.2 Service Loads	66
	8.2.3 Experimental Investigation	67
	8.2.4 Structural Hot-Spot Stress Determination	68
	8.2.5 S-N Curve Based on Nominal Stress	69
	8.3 Fatigue Assessment	70
	8.4 Conclusion	70
	Reference	70
	9 Case Study 3: Web Frame Corner	71
	9.1 Introduction	71
	9.2 Computation of the Structural Hot-Spot Stress	72
	9.2.1 Finite Element Modelling	72
	9.2.2 Computation of Structural Hot-Spot Stresses	73
	9.3 Fatigue Tests	74
	9.3.1 Performance of the Tests	74
	9.3.2 Observed Fatigue Lives	74
	9.3.3 Comparison with Design S-N Curves	75
	Reference	76
	10 Case Study 4: Loaded Stiffener on T-Bar	77
	10.1 Introduction	77
	10.2 Computation of the Structural Hot-Spot Stress	77
	10.2.1 Finite Element Modelling	77
	10.2.2 Determination of the Structural Hot-Spot Stress by Extrapolation	79
	10.2.3 Determination of the Structural Stress According to Dong	80
	10.2.4 Determination of the Structural Stress According to Xiao/Yamada	82
	10.3 Estimation of the Design Fatigue Life	82
	10.3.1 Fatigue Life Determined from Extrapolated Stress	82
	10.3.2 Fatigue Life Determined from Dong’s Approach	82
	10.3.3 Fatigue Life Determined from Xiao/Yamada’s Approach	83
	10.3.4 Comparison with Test Results	83
	References	83
	Appendix	84
	Symbols	84