PSI - Issue 18

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

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ScienceDirect

Procedia Structural Integrity 18 (2019) 549–555

25th International Conference on Fracture and Structural Integrity Plastic deformation and failure of solids with stress state dependent properties Evgeny Lomakin a, b *, Boris Fedulov a, c a Lomonosov MSU, Faculty of Mechanics and Mathematics, Leninskiye Gory, Main Building, Moscow 119991, Russia b Perm National Research Polytechnic University, 29 Komsomolsky prospekt, Perm 614990, Russia, c CDMM, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, Moscow 121205, Russia Abstract The plastic and strength properties of many structural materials depend on the type of external forces; in particular, they have different stress-strain curves under the conditions of uniaxial tension, uniaxial compression, different types of biaxial and triaxial loadings. This effect is concerned some structural features of polycrystalline alloys. Based on the analysis of experimental data, a possible approach to describe the dependence of plastic characteristics of materials on the stress state type realized under loading is proposed. The plasticity condition for the materials of stress state dependent properties is represented in corresponding generalized form, which includes some of well-known plasticity conditions in different particular cases. The constitutive equations to describe simultaneously the anisotropy and stress state dependence of plastic material properties are formulated. The results of experimental studies of plastic properties of aluminum alloy are analyzed with the use of proposed model. 25th International Conference on Fracture and Structural Integrity Plastic deformation and failure of solids with stress state dependent properties Evgeny Lomakin a, b *, Boris Fedulov a, c a Lomonosov MSU, Faculty of Mechanics and Mathematics, Leninskiye Gor , Main Building, Moscow 119991, Russia b Perm National Research Polyt ch ic University, 29 Komsomo sky prospekt, Perm 614990, Russia, c CDMM, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, Moscow 121205, Russia Abstract The plastic and stre gth properties of many structural materials depend on the ty e of external forces; in particular, they have different stress-strain curves u der the conditions of uniaxial tension, uniaxial compression, diff re t types of biaxial and triaxial loadings. This effect is concerned some structural features of polycrystalline alloy . Based on the analysis of experimental d ta, a possible approach to describe the dependence of plastic characteristics of mat rials on the str ss stat type realized und r l a i is proposed. The plasticity condition for the materials of stress state depend nt properties is represented in correspondi g gen ralized form, which includes some of well-known plasticity co ditions in different particular cases. The constitutiv equations to describe sim ltane usly the anisotropy and stress state dependence of plastic material r erties are formulated. The results of experimental studies of plastic properties of aluminum alloy are analyzed with the use of proposed model.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.

Keywords: plasticity; anisotropy; stress state dependency; triaxiality; pressure treatment; aluminum alloy. Keywords: plasticity; anisotropy; stress state dependency; triaxiality; pressure treatment; aluminum alloy.

1. Introduction Many structural materials display anisotropic plastic properties of different degree. This anisotropy may be the result of manufacture and forming processes of materials. Along with anisotropy, their behavior may demonstrate the asymmetry of mechanical properties. The simplest example of this asymmetry is the difference of the stress-strain curves and the yield limits under conditions of tension and compression in the same directions in a material. These 1. Introduction Many structural materials display anisotropic plastic properties of different degree. This anisotropy may be the result of manufacture and forming processes of materials. Along with anisotropy, their behavior may demonstrate the asymmetry of mechanical properties. The simplest example of this asymmetry is the difference of the stress-strain curves and the yield limits under conditions of tension and compression in the same directions in a material. These

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * vgeny Lomakin. Tel.: +7-916-957-75-43; fax: +7-495-939-20-90. E-mail address: evlomakin@yandex.ru * Evgeny Lomakin. Tel.: +7-916-957-75-43; fax: +7-495-939-20-90. E-mail address: evlomakin@yandex.ru

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2019.08.199