A simple fatigue propagation threshold approach to estimate the fatigue resistance of components

CHAPETTI, M.D.

Melbourne

Congreso; 11th International Fatigue Congress; 2014

RMIT University and The International Steering Committee of Fatigue

A simple fatigue threshold approach is presented as a simple tool to estimate the high cycle fatigue resistance of components from fatigue data of plain material (intrinsic properties). The fatigue resistance is study by using a threshold curve for fatigue crack propagation which includes the short crack regime (a function of crack length, a). The approach accounts for to the effective driving force applied to the crack as the difference between the total applied driving force given by the applied stress distribution of the analyzed geometrical and loading configuration, ?´K(a), and the threshold for fatigue crack propagation of the material of the component, ?´Kth(a). The Chapetti¡¦s model is used to estimate the threshold to high cycle fatigue crack propagation by using the plain fatigue limit, ?´?ãeR, the threshold for long crack, ?´KthR, and the microstructural characteristics dimension d (e.g. grain size). Applications to the analysis of the fatigue resistance of notched components and their fatigue sensitivity to defects are presented.