PSI - Issue 40

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

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Procedia Structural Integrity 40 (2022) 470–476

© 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 scientific committee of the15th International Conference on Mechanics, Resources and Diagnostics of Materials and Structures. Abstract The regularities and mechanisms of the elastoplastic strain of structural steels of two different types under two-stage cyclic loading regime conditions combining multicycle fatigue loading and hard elastoplastic strain under repeated overloading are considered. Based on experimental results and metallographic studies, repeated elastoplastic overloads on changes in the structural state of the material, mechanisms of fatigue damage accumulation, and lifetime indicators compared to the stationary process of cyclic loading are evaluated. It is shown that the combination of multicycle loading modes and low-cycle overloading leads to a change in fatigue resistance mechanisms of steels and changes in fatigue life depending on the loading history. Predict the effect of pre-elastoplastic loading of different types of metals, a change ratio in lifetime depending on the parameters of the two-step cyclic loading regime is proposed. © 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 scientific committee of the15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures. Keywords: Non-stationary cyclic loading; Low-cycle overloads; Destruction; Destructive strain; Microstructural analysis; Fatigue damage 1. Introduction Operating conditions of a considerable part of technical systems and mechanisms are characterized by intensive alternating cyclic loads combined with high-level overloads, which can cause plastic strain, including alternating 15th International Conference on Mechanics, Resource and Diagnostics of Materials and Stru tures Steel fatigue under non-stationary cyclic loading with low cycle overloads A.V. Zinin*, E.V. Sintsova, B.I. Bolotnikov Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, 125993, Russia Abstract The regularities and mechanisms of the elastoplastic strain of structural steels of two different types under two-stage cyclic loadin reg m co itions combining multicycle fatigue loading and h rd la t plastic strain under repeat d overloading are c ns dered. Based on experi ental res lts and metallographic stu ies, repea ed elastopl stic overloads on changes in th structural state of the material, mechani ms of fatigue dam ge a cumulation, and lif time indicators compared to the stat onary p o ess of cyclic loading a e evaluated. It i shown that the combination of multicycl load g mode and low-cycle overloading leads to a change in fati ue r sistanc mechanisms of s eels and ch nges in fatigue lif depe ding on the loading hist ry. Predict the effect of pre-elastoplastic loading of different type of metals, change ratio in lifetim epending on the parameters of the wo-st p cyclic loading regime is prop se . © 2022 The Authors. Publish d 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 u der re ponsibility of scientific committe of the15th Int rnational Co ference o Mechanics, Resource and Diagnostics of Materials and Structures. Keywords: Non-stationary cyclic loading; Low-cycle overloads; Destruction; Destructive strain; Microstructural analysis; Fatigue damage 1. Introduction Operating conditions of a considerable part of technical systems and mechanisms are characterized by intensive alternating cy lic load combined with high-level overload , which can cause plastic strain, including alternating 15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures Steel fatigue under non-stationary cyclic loading with low cycle overloads A.V. Zinin*, E.V. Sintsova, B.I. Bolotnikov Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, 125993, Russia

* Corresponding author. Tel.: +7-916-652-9209 е -mail address: allzin@yandex.ru * Corresponding author. Tel.: +7-916-652-9209 е -mail address: allzin@yandex.ru

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 scientific committee of the15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures. 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 u der re ponsibility of scientific committe of the15th Int rnational C ference o Mechanics, Resource and Diagnostics of Mate ials and Structures.

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 scientific committee of the15th International Conference on Mechanics, Resources and Diagnostics

of Materials and Structures. 10.1016/j.prostr.2022.04.064