Issue 48

318 L. Reis et alii, Frattura ed Integrità Strutturale, 48 (2019) 318-331; DOI: 10.3221/IGF-ESIS.48.31 Focused on the “Portuguese contributions for Structural Integrity” Damage evaluation under complex fatigue loading conditions L. Reis IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal luis.g.reis@tecnico.ulisboa.pt ; http://orcid.org/0000-0001-9848-9569 J. Caxias, H. Soares, P. R. Costa Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal joaohcaxias@gmail.com, soares.hn@gmail.com, pedro.r.costa@ist.utl.pt V. Anes Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro, 1, 19559-007, Lisbon, Portugal vanes@dem.isel.pt M. Freitas IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal manuel.freitas@tecnico.ulisboa.pt A BSTRACT . Fatigue damage and life assessment of multiaxial loadings is still an issue yet to resolve. Many methods have been proposed with promising agreements with the experimental results. However, the performance of such methods is, more than often, purely based on fatigue tests with simple loading conditions. In this work the stress scale factor (SSF) criterion and the virtual cycle counting (vcc) method are used to estimate fatigue life and damage accumulation with two damage accumulation rules. Fatigue tests were carried out with three different variable amplitude random loadings, applied to several specimens made from a 42CrMo4 high-strength steel. Fatigue crack plane measurements were compared with predictions from several critical plane models. The applied methods provided very acceptable results making the SSF package (SSF equivalent stress and virtual cycle counting method) a good method to estimate fatigue life and assessment of the damage accumulation in random fatigue loadings. K EYWORDS . Multiaxial fatigue; Fatigue life; Damage accumulation; SSF; Critical plane models. Citation: Reis, L., Caxias, J., Soares, H., Costa, P. R., Anes, V., de Freitas, M., Damage evaluation under complex fatigue loading conditions, Frattura ed Integrità Strutturale, 48 (2019) 318-331. Received: 26.09.2018 Accepted: 28.11.2018 Published: 01.04.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.