https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 15 May 2026 23:07:13 GMT 2026-05-15T23:07:13Z http://hdl.handle.net/10985/11194 Theoretical analysis, infrared and structural investigations of energy dissipation in metals under cyclic loading PLEKHOV, O.A; SAINTIER, Nicolas; PALIN-LUC, Thierry; UVAROV, S. V.; NAIMARK, O.B The infrared and structural investigations of energy dissipation processes in metals subjected to cyclic loading have given impetus to the development of a new thermodynamic model with the capability of describing the energy balance under plastic deformation. The model is based on the statistical description of the mesodefect ensemble evolution and its influence on the dissipation ability of the material. Constitutive equations have been formulated for plastic and structural strains, which allow us to describe the stored and dissipated parts of energy under plastic flow. Numerical results indicate that theoretical predictions are in good agreement with the experimentally observed temperature data. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10985/11194 2007-01-01T00:00:00Z PLEKHOV, O.A SAINTIER, Nicolas PALIN-LUC, Thierry UVAROV, S. V. NAIMARK, O.B The infrared and structural investigations of energy dissipation processes in metals subjected to cyclic loading have given impetus to the development of a new thermodynamic model with the capability of describing the energy balance under plastic deformation. The model is based on the statistical description of the mesodefect ensemble evolution and its influence on the dissipation ability of the material. Constitutive equations have been formulated for plastic and structural strains, which allow us to describe the stored and dissipated parts of energy under plastic flow. Numerical results indicate that theoretical predictions are in good agreement with the experimentally observed temperature data. http://hdl.handle.net/10985/11227 Fatigue crack initiation and growth in a 35CrMo4 steel investigated by infrared thermography PLEKHOV, O.A; PALIN-LUC, Thierry; SAINTIER, Nicolas; UVAROV, S. V.; NAIMARK, O.B The present work is devoted to the investigation of fatigue crack initiation and growth in middle-cycle fatigue (∼105 cycles). Smooth specimens made of 35CrMo4 quenched and tempered steel were loaded in fully reversed plane bending. Temperature field evolution in time was recorded with an infrared camera. The experimental results show that the local heating of metal under fatigue loading is a sensitive and accurate enough manifestation of small fatigue crack initiation. It is shown that the time evolution of the spatial standard deviation of the temperature field can be used to investigate the damage localization and to monitor both the crack initiation and the current location of the fatigue crack tip. This should help to investigate the behaviour of defect during cyclic loading. Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/10985/11227 2005-01-01T00:00:00Z PLEKHOV, O.A PALIN-LUC, Thierry SAINTIER, Nicolas UVAROV, S. V. NAIMARK, O.B The present work is devoted to the investigation of fatigue crack initiation and growth in middle-cycle fatigue (∼105 cycles). Smooth specimens made of 35CrMo4 quenched and tempered steel were loaded in fully reversed plane bending. Temperature field evolution in time was recorded with an infrared camera. The experimental results show that the local heating of metal under fatigue loading is a sensitive and accurate enough manifestation of small fatigue crack initiation. It is shown that the time evolution of the spatial standard deviation of the temperature field can be used to investigate the damage localization and to monitor both the crack initiation and the current location of the fatigue crack tip. This should help to investigate the behaviour of defect during cyclic loading. http://hdl.handle.net/10985/12046 Experimental and Theoretical Study of Multiscale Damage-Failure Transition in Very High Cycle Fatigue BETEKHTIN, V.I.; KADOMTSEV, A.G.; NARYKOVA, M.V.; BANNIKOV, M.V.; ABAIMOV, S.G.; AKHATOV, I. S.; PALIN-LUC, Thierry; NAIMARK, O.B Multiscale mechanisms of failure of metals (Armco iron, titanium, aluminum) are studied for high cycle and very high cycle fatigue. By correlating with the results of structural studies, a theoretical approach is developed to describe fatigue crack kinetics in damaged material under high cycle and very high cycle fatigue loading conditions. Stages of crack nucleation and propagation are analyzed using the profilometry data from the fracture surface. The scale invariance of fracture surface roughness is established, which allows an explanation of the self-similar nature of fatigue crack kinetics under high cycle and very high cycle fatigue. Variation of elastic-plastic properties of Armco iron under very high cycle fatigue is studied using an acoustic resonance method. It is found that the material density decreases during fatigue damage accumulation, with the minimum of the material density in the bulk of the specimen. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/12046 2017-01-01T00:00:00Z BETEKHTIN, V.I. KADOMTSEV, A.G. NARYKOVA, M.V. BANNIKOV, M.V. ABAIMOV, S.G. AKHATOV, I. S. PALIN-LUC, Thierry NAIMARK, O.B Multiscale mechanisms of failure of metals (Armco iron, titanium, aluminum) are studied for high cycle and very high cycle fatigue. By correlating with the results of structural studies, a theoretical approach is developed to describe fatigue crack kinetics in damaged material under high cycle and very high cycle fatigue loading conditions. Stages of crack nucleation and propagation are analyzed using the profilometry data from the fracture surface. The scale invariance of fracture surface roughness is established, which allows an explanation of the self-similar nature of fatigue crack kinetics under high cycle and very high cycle fatigue. Variation of elastic-plastic properties of Armco iron under very high cycle fatigue is studied using an acoustic resonance method. It is found that the material density decreases during fatigue damage accumulation, with the minimum of the material density in the bulk of the specimen. http://hdl.handle.net/10985/10516 Scaling invariance of fatigue crack growth in gigacycle loading regime OBORIN, V.; BANNIKOV, M.V.; NAIMARK, O.B; PALIN-LUC, Thierry The role of the collective behavior of defect ensembles at the crack tip and the laws of fatigue crack propagation in R4 high-strength steel have been studied under conditions of symmetric tension-compression gigacycle loading at 20 kHz. At every stage of the fatigue crack growth, replicas from the sample side surface were taken and studied by the method of three-dimensional relief profilometry (using NewView interferometer profilometer) so as to study the scaling-invariant laws of defect-related structure evolution. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/10516 2010-01-01T00:00:00Z OBORIN, V. BANNIKOV, M.V. NAIMARK, O.B PALIN-LUC, Thierry The role of the collective behavior of defect ensembles at the crack tip and the laws of fatigue crack propagation in R4 high-strength steel have been studied under conditions of symmetric tension-compression gigacycle loading at 20 kHz. At every stage of the fatigue crack growth, replicas from the sample side surface were taken and studied by the method of three-dimensional relief profilometry (using NewView interferometer profilometer) so as to study the scaling-invariant laws of defect-related structure evolution. http://hdl.handle.net/10985/8819 Scaling Invariance of Fatigue Crack Growth in Gigacycle Loading Regime OBORIN, V.; BANNIKOV, M.V.; NAIMARK, O.B; PALIN-LUC, Thierry The role of the collective behavior of defect ensembles at the crack tip and the laws of fatigue crack propagation in R4 high strength steel have been studied under conditions of symmetric tension–compression gigacycle loading at 20 kHz. At every stage of the fatigue crack growth, replicas from the sample side surface were taken and studied by the method of three dimensional relief profilometry (using NewView interferometer profilometer) so as to study the scaling invariant laws of defect related structure evolution. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8819 2010-01-01T00:00:00Z OBORIN, V. BANNIKOV, M.V. NAIMARK, O.B PALIN-LUC, Thierry The role of the collective behavior of defect ensembles at the crack tip and the laws of fatigue crack propagation in R4 high strength steel have been studied under conditions of symmetric tension–compression gigacycle loading at 20 kHz. At every stage of the fatigue crack growth, replicas from the sample side surface were taken and studied by the method of three dimensional relief profilometry (using NewView interferometer profilometer) so as to study the scaling invariant laws of defect related structure evolution. http://hdl.handle.net/10985/10517 Experimental Investigations of Anomalous Energy Absorption in Nanocrystalline Titanium under Cyclic Loading Conditions PLEKHOV, O.A; NAIMARK, O.B; VALIEV, R.Z; SEMENOVA, I.P; SAINTIER, Nicolas; PALIN-LUC, Thierry An infrared thermographic scanning technique has been used to study the energy absorption and dissipation under cyclic loading conditions in the nanostructural bulk titanium obtained by severe plastic deformation of an initial coarse-grained material. It is established that the character of energy absorption in the nanocrystalline material exhibits qualitative changes, which are related to specific features of interactions in the ensemble of grain-boundary defects. The mechanisms of energy absorption are explained within the framework of notions of a new class of critical phenomena in mesoscopic systems with defects featuring structure-scaling transitions. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/10985/10517 2008-01-01T00:00:00Z PLEKHOV, O.A NAIMARK, O.B VALIEV, R.Z SEMENOVA, I.P SAINTIER, Nicolas PALIN-LUC, Thierry An infrared thermographic scanning technique has been used to study the energy absorption and dissipation under cyclic loading conditions in the nanostructural bulk titanium obtained by severe plastic deformation of an initial coarse-grained material. It is established that the character of energy absorption in the nanocrystalline material exhibits qualitative changes, which are related to specific features of interactions in the ensemble of grain-boundary defects. The mechanisms of energy absorption are explained within the framework of notions of a new class of critical phenomena in mesoscopic systems with defects featuring structure-scaling transitions. http://hdl.handle.net/10985/8816 Elastic–Plastic Transition in Iron: Structural and Thermodynamic Features PLEKHOV, O.A; NAIMARK, O.B; SAINTIER, Nicolas; PALIN-LUC, Thierry The structural and thermodynamic features of the elastic–plastic transition in armco iron and its plastic deformation are studied. Energy storage in iron is shown to have a nonlinear character and be accompanied by wavelike heat dissipation. To describe the energy balance in the plastically deformed metal, a theoretical model is proposed based on a statistical description of the evolution of an ensemble of typical mesodefects (microshears). Moreover, a procedure is developed to experimentally determine the dependence of the potential of the medium on the mesodefect density using infrared scanning data. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10985/8816 2009-01-01T00:00:00Z PLEKHOV, O.A NAIMARK, O.B SAINTIER, Nicolas PALIN-LUC, Thierry The structural and thermodynamic features of the elastic–plastic transition in armco iron and its plastic deformation are studied. Energy storage in iron is shown to have a nonlinear character and be accompanied by wavelike heat dissipation. To describe the energy balance in the plastically deformed metal, a theoretical model is proposed based on a statistical description of the evolution of an ensemble of typical mesodefects (microshears). Moreover, a procedure is developed to experimentally determine the dependence of the potential of the medium on the mesodefect density using infrared scanning data.