Use of SED approach to predict the fatigue behaviour of Aluminium V-Notched Samples

The thesis presents a review on the classical methods for predicting fatigue life, especially for what concern the theory necessary to develop the model and the computations of the second part of the work, with a particular focus on the Strain Energy Density method, developed by Berto, Lazzarin et al. and all its advantages. The aim of the work is that of using SED approach to predict the fatigue behavior of the aluminum alloy 6082-T6. The following steps are made in order to develop the model necessary to reach this goal: 1. Fatigue tests of 15 aluminum V-notched specimens; 2. Implementation of the elastic model and plot of the Wöhler curves using SED; 3. Analysis of the differences between elastic and plastic models, developed using the FEM software Ansys; 4. Computation of the Notch Stress Intensity Factor using SED and stress and comparison of the numerical values; 5. Computation of the number of cycles necessary to nucleate and propagate the crack and definition of two equivalent parameters, C’ and n’, useful to apply the Paris law to SED; 6. Plot of the Haigh diagrams using SED; 7. Use of the equivalent stress and SED, computed using Gerber and Goodman`s relation.