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For insignificant size effect of smooth specimen under cyclic tensile load and difficulty in the fatigue test for large-scale component, fatigue life prediction method for large-scale component was presented by experiments of small samples. Firstly, simulate-scale model was created based on fatigue simulation test, and size coefficient of notched-sample was introduced. Secondly, characteristic parameter that represents the influences of size change condition on fatigue properties was introduced, and an empirical size coefficient formula was obtained by utilizing the tested fatigue life results of geometrically similar specimens (Kt=2, Kt=3) made in two kinds of materials (Steel 45, Q235). Simultaneously considering interaction of size, stress concentration and surface quality, a fatigue comprehensive correction factor model was proposed, and its validity was proved. Finally, on the basis of the nominal stress method, fatigue life of large-scaled C-type plate was successfully predicted after modifying S-N curve of plate material through fatigue comprehensive correction factor model. This method was in well accordance with the practical situation, and fatigue life prediction was more reasonably. Furthermore, this method provided a new way for fatigue assessment of large-scale component under tension.
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