PSI - Issue 23

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Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Structural Integrity Procedia 00 (2019) 000 – 000

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ScienceDirect

Procedia Structural Integrity 23 (2019) 565–570

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers © 201 9 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. In t e study w i ve tigated develop ent of surface icrocra ks under static lo ding of flat specimens with differ nt geometry (s ooth, key-hole and sharp notch) from low-(0.2%C), medium carbon (0.45%C) and stainless (0.12C-18Cr-9Ni) steels. The real dam ge estimation was carried out by studying the microcracks patterns at v r ious stages of specimen’s deformation. The increas in damag urin tension was characterized by a change in such damage parameters as concentration k -criterion and the relative area of the d surfac S* occupi d by microcracks. Staging of damage accumulation process was established by analyzing changes in damage p rameters at different stages of loading. The influence of the stress concentration on the regularities of damage accumulation was analyzed. © 201 9 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. 9th International Conference on Materials Structure and Micromechanics of Fracture The Effect of Stress Concentration and Material Structure on the Kinetics of Damage Accumulation I.O. Sinev a *, M.R. Tyutin a , and L.R. Botvina a a A.A.Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, 49 Leninskiy prospect, Moscow, 119334, Russia 9th International Conference on Materials Structure and Micromechanics of Fracture The Effect of Stress Concentration and Material Structure on the Kinetics of Damage Accumulation I.O. Sinev a *, M.R. Tyutin a , and L.R. Botvina a a A.A.Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, 49 Leninskiy prospect, Moscow, 119334, Russia Abstract Abstract In the study we investigated development of surface microcracks under static loading of flat specimens with different geometry (smooth, key-hole and sharp notch) from low-(0.2%C), medium carbon (0.45%C) and stainless (0.12C-18Cr-9Ni) steels. The real damage estimation was carried out by studying the microcracks patterns at var ious stages of specimen’s deformation. The increase in damage during tension was characterized by a change in such damage parameters as concentration k -criterion and the relative area of the damaged surface S* occupied by microcracks. Staging of damage accumulation process was established by analyzing changes in damage parameters at different stages of loading. The influence of the stress concentration on the regularities of damage accumulation was analyzed.

Keywords: surface microcracks, damage, stress concentration, microcracks kinetics Keywords: surface microcracks, damage, stress concentration, microcracks kinetics

1. Introduction 1. Introduction

Assessment of the condition and residual lifetime material of structure during operation is the most important task in the industry to prevent failures, accidents and disasters. The lifetime of metal constructions during static, and, especially, during cyclic loading, is largely determined by the kinetics of small defects formed during the loading process. For the experimental research of the microdefects development in the material studied, various indirect methods are most often used (Smedt et al., 2014). The most common are acoustic methods, including the method of Assessment of the co dition and residual lifetime mat ial of struc ure during operation is the most important task in the industry to prevent failures, accidents and disasters. The lifetime of metal constructions ri static, a d, especially, during cyclic loading, is largely d termined by the kinetics of small defects formed uring the loading process. For the exp rimental research of the microdefects devel pment in the aterial studie , various indirect methods are most often used (Smedt et al., 2014). The most common are acoustic methods, including the method of

* Corresponding author. Tel.: 8-499-135-96-83; fax: +7 (499) 135-86-80 E-mail address: mtyutin@imet.ac.ru * Correspon ing author. Tel.: 8-499-135-96-83; fax: +7 (499) 135-86-80 E-mail address: mtyutin@imet.ac.ru

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the scientific committee of the IC MSMF organizers.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers 10.1016/j.prostr.2020.01.146