CONICET | Buscador de Institutos y Recursos Humanos

Current fracture mechanics methods and technologies for fatigue design are based on crack initiation or long crack behavior, use nominal or equivalent stresses for a given analyzed configuration and do not allow the study of the influence of the different geometrical, mechanical and microstructural parameters involved in the definition of the fatigue behavior of the analyzed component. The present work is concerned with the attempt to predict the fatigue strength of metallic components by means of a fracture mechanics approach that takes into account the fatigue behavior of short cracks, proposing changes in the transition concepts between initiation and propagation stages so widely and currently accepted. The methodology estimates the fatigue crack propagation rate as a function of the difference between the applied driving force and the material threshold for crack propagation, function of crack length. In this way, the total fatigue crack propagation rate and the nominal fatigue thresholds can be estimated. Estimations and comparisons of experimental data and bibliography reports are carried out for applications in welded joints.