PSI - Issue 28

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

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

Procedia Structural Integrity 28 (2020) 1416–1425

© 2020 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 European Structural Integrity Society (ESIS) ExCo Abstract A numerical technique based on the finite element method of deformation processes and damage accumulation in structural elements made of heat-resistant alloys under high-temperature creep that accounts for the effect of neutron radiation is developed. The mechanical behavior of the material is described on the basis of previously developed general model of damaged material and creep model for unirradiated heat-resistant alloys, supplemented with taking into account the irradiation effect on creep rate and brittle fracture emerging in a given range of temperature and radiation intensity. The constitutive relations for creep model of irradiated material were obtained by modifying the creep model of the unirradiated material: a material function taking into account the effect of neutron flux on the strain rate of thermal creep is introduced; a material function taking into account the effect of neutron flux on creep surface radius is introduced; a material function taking into account the effect of neutron flux on the ultimate value of creep dissipation energy is introduced. To simulate the processes of brittle fracture during creep under neutron radiation, it is assumed that the destructive values of the effective normal stresses are the function of temperature, neutron flux and the current value of accumulated creep strain. To verify and illustrate the capabilities of the developed methodological and software tools, a number of problems on modeling the processes of high-temperature creep and fracture of structural elements made of heat-resistant alloy under consideration are solved. © 2020 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 European Structural Integrity Society (ESIS) ExCo Keywords: creep, high-temperature loading, neutron radiation, damage accumulation, FEM 1st Virtual European Conference on Fracture Simulation of fracture of heat-resistant alloys under creep and neutron irradiation conditions Vasilii Gorokhov*, Dmitrii Kazakov, Sergei Kapustin, Yuriy Churilov Research Institute for Mechanics, National Research Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, building 6, Nizhny Novgorod 603950, Russian Federatio Abstract A numerical technique based on the finite element method of deformation processes and damage accumulation in structural elements mad of heat-re istant alloys under high-temperature creep that ac ount for the eff ct of neu r radiation is developed. Th mec anical behavior f the material is described on th basis of previously dev loped general model of d maged mat rial and creep model for unirradiated he -resistant alloys, suppl mented with taking into account the irradiati n effect on creep rate and brittle fracture emerging in a giv n r ge of temperatur an radia ion inte sity. The constitutive relations f r model of irradiated material were obt ined by modifying the creep mo el of he unirrad ated material: a mate ial fu cti n taking into account the effect of neut on flux on the stra n rate of th rmal cr ep is introduced; a aterial function t king into account the effect of neutron flux on creep surface radius is introduced; a mater al function taking into account the effect of neutro flux on the ultimate va e f cre p dissipation energy s introduced. To simulate the processes of brittle fractur during creep under neutron radi ion, it is assumed that the destructive val es of the effec ive normal tresses are the f nction of tem erature, t flux and the current value of accumula ed creep train. To verify a d illustrate the capabilities f the d veloped method logical softwa e tools, a number of problems on modeling th processes of high- emper ture creep and fracture of structura elements made of heat-resistant alloy under con iderati n are solv d. © 2020 The Au hors. 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 European Structural Integri y Society (ESIS) ExC K ywords: creep, high-temperature loading, neutron radiation, damage accumulation, FEM 1st Virtual European Conference on Fracture Simulation of fracture of heat-resistant alloys under creep and neutron irradiation conditions Vasilii Gorokhov*, Dmitrii Kazakov, Sergei Kapustin, Yuriy Churilov Research Institute for Mechanics, National Research Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, building 6, Nizhny Novgorod 603950, Russian Federation

* Corresponding author. Tel.: +7-831-465-6611; fax: +7-831-465-6611. E-mail address: vas-gor@rambler.ru * Corresponding author. Tel.: +7-831-465-6611; fax: +7-831-465-6611. E-mail ad ress: vas-gor@rambler.ru

2452-3216 © 2020 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 European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 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 European Structural Integri y So i ty (ESIS) ExC

2452-3216 © 2020 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 European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.114