PSI - Issue 41

ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 41 (2022) 421–429

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. Abstract T evalu tio of fatigue damage represents a fundamental challenge for the de p comprehension of th fatigue phenomena. In this work, a real-time monitoring of fatigue damage by Elect ical R i tance method is carried ut on a batch of AISI 316L sta less steel specimens with U-shaped notc at different tress levels. The temp rature of the spec mens w s als on-lin monitored during the tes u ing three thermo ouples type T o lim nate heating due to cycling load a d Joule effect. The experimental results show that resistance decreases in the initi l stages of and subsequ n ly, starting from ab ut 20-40% of the fatigue life, shows a rapid ncr as associated to the fatigue d mage clos to the notch tip. Bef re final f ilure, from about 80-90% of the fatigue life, the resista ce increase rapidly in the propagation phases f crack. This latter behavio r is coherent with the r duction in stiffness obtained by process ng fatigue data of e tested specimens. In c nclusion, the pplied xperimental method proved to be effectively valid for predicting with accuracy the evolution of fatigue damage of metals. © 2022 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. 2nd Mediterranean Conference on Fracture and Structural Integrity Electrical Resistance measurements for fatigue damage prediction of AISI 316L stainless steel R. Nobile a , A. Saponaro a, * a University of Salento – Department of Engineering for Innovation, Via per Monteroni, 73100 Lecce, Italy Abstract The evaluation of fatigue damage represents a fundamental challenge for the deep comprehension of the fatigue phenomena. In this work, a real-time monitoring of fatigue damage by Electrical Resistance method is carried out on a batch of AISI 316L stainless steel specimens with U-shaped notch at different stress levels. The temperature of the specimens was also on-line monitored during the test using three thermocouples type T to eliminate heating due to cycling load and Joule effect. The experimental results show that resistance decreases in the initial stages of fatigue and subsequently, starting from about 20-40% of the fatigue life, shows a rapid increase associated to the fatigue damage close to the notch tip. Before final failure, from about 80-90% of the fatigue life, the resistance increases rapidly in the propagation phases of the crack. This latter behaviour is coherent with the reduction in stiffness obtained by processing fatigue data of the tested specimens. In conclusion, the applied experimental method proved to be effectively valid for predicting with accuracy the evolution of fatigue damage of metals. 2nd Mediterranean Conference on Fracture and Structural Integrity Electrical Resistance measurements for fatigue damage prediction of AISI 316L stainless steel R. Nobile a , A. Saponaro a, * a University of Salento – Department of Engineering for Innovation, Via per Monteroni, 73100 Lecce, Italy 1. Introduction Structural components generally are subjected to time-varying loads during service life. So, it is fundamental to know the fatigue damage evolution and fatigue life of the material before selecting these alloys for built different structures (Palit Sagar et al. (2006)). Damage is an important factor in fatigue studies and many researcher have 1. Introduction Structur l components generally re subject d to time-varying loads during service lif . S , it is fundamental to know the fatigue damage evolution and fati ue life of the material before selecting these alloys fo built different structures (Palit Sagar et al. (2006)). Damage is an important factor in fatigue studies and many researcher have Keywords: Fatigue; Metals; Damage evolution; Electrical Resistance. Keywords: Fatigue; Metals; Damage evolution; Electrical Resistance.

* Corresponding author. Tel.: +39 0832 297786; fax: +39 0832 297768. E-mail address: andrea.saponaro@unisalento.it * Corresponding author. Tel.: +39 0832 297786; fax: +39 0832 297768. E-mail address: andrea.saponaro@unisalento.it

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the MedFract2Guest Editors. 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an ope access article under t CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the MedFract2Guest Editors.

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. 10.1016/j.prostr.2022.05.048