A survey on fatigue life analysis approaches for metallic notched components under multi-axial loading

In this paper, several fatigue failure approaches of metallic notched components under multi-axial loading in recent decades are reviewed in detail. They are classified into three categories according to their different fatigue physical mechanisms and hypotheses: nominal stress approach, local stress–strain approach and the theory of critical distance. The accuracy, applicable range and computing complexity of these three different fatigue failure theories of metallic notched specimen under multi-axial fatigue loading are given. It is concluded that theory of critical distance accords with experimental results under multi-axial fatigue loading and it gives unambiguous explanation for physical mechanism of fatigue damage. However, the computing process is complex, especially under non-proportional fatigue loading, and the key parameter of theory of critical distance is difficult to calculate especially in engineering. These difficulties limit the application of theory of critical distance.