Paris' law

About: Paris' law is a research topic. Over the lifetime, 13815 publications have been published within this topic receiving 224818 citations. The topic is also known as: Paris-Erdogan law.

Load interaction effects during fatigue crack growth under variable amplitude loading—a literature review. Part II: qualitative interpretation

Abstract: The current understanding of the underlying reasons behind the load interaction effects in fatigue crack growth under variable amplitude loading is presented. Mechanistic arguments proposed to control the load interaction phenomena are reviewed and evaluated based on their capability to qualitatively explain empirical trends in variable amplitude fatigue crack growth summarized in Part I [Fatigue Fract, Engng Mater. Struct. 1998. 21(8), 987-1006] of the present paper. Mechanisms linked to plastic straining at the crack tip enable an interpretation of the majority of the experimental results. Some observations, however, which cannot be understood in terms of plasticity-induced crack closure, or which are even in contradiction with the crack closure approach, indicate a possible role of other factors. A general conclusion is that conditions under which various phenomena can affect variable amplitude fatigue crack growth and interactions between them are insufficiently recognized.

Fatigue Failure of Metals

Abstract: 1 Fundamental concepts and fatigue processes.- 1.1 Fatigue stresses.- 1.2 Wohler fatigue diagrams.- 1.3 The low-cycle range.- 1.3.1 General testing methods. Fundamental formulae.- 1.3.2 The influence of various factors and testing conditions. Hardening and softening hypotheses.- 1.4 The stages in fatigue processes.- References.- 2 Fatigue phenomena.- 2.1 Introductory remarks.- 2.2 Slip bands.- 2.2.1 Slip bands in the region above the fatigue limit.- 2.2.2 Slip bands in the range below the fatigue limit.- 2.3 Extrusions and intrusions.- 2.3.1 Extrusions and intrusions in polycrystalline iron and copper.- 2.3.2 Models and hypotheses of extrusion and intrusion formation.- 2.4 Fatigue cracks.- 2.4.1 Crack sources and propagation.- 2.4.2 Microcracks in polycrystalline iron.- 2.5 Supplementary methods of studying fatigue phenomena.- 2.5.1 Fatigue phenomena and changes in physical properties.- 2.5.2 Ionic bombardment (etching) method.- 2.5.3 The thermal etching method.- 2.5.4 Fatigue phenomena and surface microroughness.- 2.6 A survey of studies on fatigue changes in different metals.- 2.6.1 Face-centered cubic metals and alloys.- 2.6.2 Body-centered cubic metals and alloys.- 2.6.3 Hexagonal close-packed metals.- 2.6.4 Microcracks initiation in electroplated steel samples.- 2.7 Theories of fatigue.- 2.7.1 General remarks and early theories.- 2.7.2 Dislocation theories and crack initiation models.- 2.7.3 Statistical theories.- 2.7.4 Energy theories.- References.- 3 Fatigue dislocation structures.- 3.1 Introduction.- 3.2 The dislocation structure in face-centered cubic metals and alloys.- 3.2.1 Copper and its alloys.- 3.2.2 Aluminium and aluminium alloys.- 3.2.3 Austenitic steels.- 3.2.4 Other metals and alloys.- 3.3 The dislocation structure in body-centered cubic metals and alloys.- 3.3.1 Iron and iron alloys.- 3.3.2 Non-ferrous metals and alloys.- 3.4 The dislocation structure in hexagonal close-packed metals and alloys.- 3.5 An attempt at a synthesis.- References.- 4 Fatigue crack growth.- 4.1 General remarks.- 4.2 Description of crack growth.- 4.3 Fundamental relations for determining the fatigue crack growth rate.- 4.4 The influence of loading conditions on fatigue crack propagation rates. Sundry problems (Examples).- 4.5 Non-propagating fatigue cracks.- References.- 5 Fatigue fractures.- 5.1 Introduction.- 5.2 Classification of fractures and their characteristic features.- 5.2.1 General classification of fractures.- 5.2.2 The fundamental types of fracture.- 5.3 The macrostructure of fatigue fractures.- 5.3.1 Specific features of fracture surfaces.- 5.3.2 The macrostructure of fractures and the loading mode (Examples).- 5.4 The microstructure of fatigue fractures.- 5.4.1 General remarks.- 5.4.2 Fatigue striations.- 5.4.3 Tire tracks.- 5.4.4 Examples of fracture microstructure and their interpretations.- 5.4.5 Concluding remarks.- References.

Effects of heterogeneity and load amplitude on fatigue rate prediction of a welded joint

Abstract: It is a contradiction to homogeneous material fatigue behavior characterized by widely used linear Paris law, welded-joint fatigue issues need to be reassessed because fatigue crack growth behavior...