The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Viggo Tvergaard - One of the best experts on this subject based on the ideXlab platform.
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effects of texture on Shear Band Formation in plane strain tension compression and bending
International Journal of Plasticity, 2007Co-Authors: Mitsutoshi Kuroda, Viggo TvergaardAbstract:Abstract In this study, effects of typical texture components observed in rolled aluminum alloy sheets on Shear Band Formation in plane strain tension/compression and bending are systematically studied. The material response is described by a generalized Taylor-type polycrystal model, in which each grain is characterized in terms of an elastic–viscoplastic continuum slip constitutive relation. First, a simple model analysis in which the Shear Band is assumed to occur in a weaker thin slice of material is performed. From this simple model analysis, two important quantities regarding Shear Band Formation are obtained: i.e. the critical strain at the onset of Shear Banding and the corresponding orientation of Shear Band. Second, the Shear Band development in plane strain tension/compression is analyzed by the finite element method. Predictability of the finite element analysis is compared to that of the simple model analysis. Third, Shear Band developments in plane strain pure bending of a sheet specimen with the typical textures are studied. Regions near the surfaces in a bent sheet specimen are approximately subjected to plane strain tension or compression. From this viewpoint, the bendability of a sheet specimen may be evaluated, using the knowledge regarding Shear Band Formation in plane strain tension/compression. To confirm this and to encompass overall deFormation of a bent sheet specimen, including Shear Bands, finite element analyses of plane strain pure bending are carried out, and the predicted Shear Band Formation in bent specimens is compared to that in the tension/compression problem. Finally, the present results are compared to previous related studies, and the efficiency of the present method for materials design in future is discussed.
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Effects of texture on Shear Band Formation in plane strain tension/compression and bending
International Journal of Plasticity, 2007Co-Authors: Mitsutoshi Kuroda, Viggo TvergaardAbstract:Abstract In this study, effects of typical texture components observed in rolled aluminum alloy sheets on Shear Band Formation in plane strain tension/compression and bending are systematically studied. The material response is described by a generalized Taylor-type polycrystal model, in which each grain is characterized in terms of an elastic–viscoplastic continuum slip constitutive relation. First, a simple model analysis in which the Shear Band is assumed to occur in a weaker thin slice of material is performed. From this simple model analysis, two important quantities regarding Shear Band Formation are obtained: i.e. the critical strain at the onset of Shear Banding and the corresponding orientation of Shear Band. Second, the Shear Band development in plane strain tension/compression is analyzed by the finite element method. Predictability of the finite element analysis is compared to that of the simple model analysis. Third, Shear Band developments in plane strain pure bending of a sheet specimen with the typical textures are studied. Regions near the surfaces in a bent sheet specimen are approximately subjected to plane strain tension or compression. From this viewpoint, the bendability of a sheet specimen may be evaluated, using the knowledge regarding Shear Band Formation in plane strain tension/compression. To confirm this and to encompass overall deFormation of a bent sheet specimen, including Shear Bands, finite element analyses of plane strain pure bending are carried out, and the predicted Shear Band Formation in bent specimens is compared to that in the tension/compression problem. Finally, the present results are compared to previous related studies, and the efficiency of the present method for materials design in future is discussed.
Mitsutoshi Kuroda - One of the best experts on this subject based on the ideXlab platform.
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effects of texture on Shear Band Formation in plane strain tension compression and bending
International Journal of Plasticity, 2007Co-Authors: Mitsutoshi Kuroda, Viggo TvergaardAbstract:Abstract In this study, effects of typical texture components observed in rolled aluminum alloy sheets on Shear Band Formation in plane strain tension/compression and bending are systematically studied. The material response is described by a generalized Taylor-type polycrystal model, in which each grain is characterized in terms of an elastic–viscoplastic continuum slip constitutive relation. First, a simple model analysis in which the Shear Band is assumed to occur in a weaker thin slice of material is performed. From this simple model analysis, two important quantities regarding Shear Band Formation are obtained: i.e. the critical strain at the onset of Shear Banding and the corresponding orientation of Shear Band. Second, the Shear Band development in plane strain tension/compression is analyzed by the finite element method. Predictability of the finite element analysis is compared to that of the simple model analysis. Third, Shear Band developments in plane strain pure bending of a sheet specimen with the typical textures are studied. Regions near the surfaces in a bent sheet specimen are approximately subjected to plane strain tension or compression. From this viewpoint, the bendability of a sheet specimen may be evaluated, using the knowledge regarding Shear Band Formation in plane strain tension/compression. To confirm this and to encompass overall deFormation of a bent sheet specimen, including Shear Bands, finite element analyses of plane strain pure bending are carried out, and the predicted Shear Band Formation in bent specimens is compared to that in the tension/compression problem. Finally, the present results are compared to previous related studies, and the efficiency of the present method for materials design in future is discussed.
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Effects of texture on Shear Band Formation in plane strain tension/compression and bending
International Journal of Plasticity, 2007Co-Authors: Mitsutoshi Kuroda, Viggo TvergaardAbstract:Abstract In this study, effects of typical texture components observed in rolled aluminum alloy sheets on Shear Band Formation in plane strain tension/compression and bending are systematically studied. The material response is described by a generalized Taylor-type polycrystal model, in which each grain is characterized in terms of an elastic–viscoplastic continuum slip constitutive relation. First, a simple model analysis in which the Shear Band is assumed to occur in a weaker thin slice of material is performed. From this simple model analysis, two important quantities regarding Shear Band Formation are obtained: i.e. the critical strain at the onset of Shear Banding and the corresponding orientation of Shear Band. Second, the Shear Band development in plane strain tension/compression is analyzed by the finite element method. Predictability of the finite element analysis is compared to that of the simple model analysis. Third, Shear Band developments in plane strain pure bending of a sheet specimen with the typical textures are studied. Regions near the surfaces in a bent sheet specimen are approximately subjected to plane strain tension or compression. From this viewpoint, the bendability of a sheet specimen may be evaluated, using the knowledge regarding Shear Band Formation in plane strain tension/compression. To confirm this and to encompass overall deFormation of a bent sheet specimen, including Shear Bands, finite element analyses of plane strain pure bending are carried out, and the predicted Shear Band Formation in bent specimens is compared to that in the tension/compression problem. Finally, the present results are compared to previous related studies, and the efficiency of the present method for materials design in future is discussed.
Matthew A. Davies - One of the best experts on this subject based on the ideXlab platform.
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on repeated adiabatic Shear Band Formation during high speed machining
International Journal of Plasticity, 2002Co-Authors: Timothy J Burns, Matthew A. DaviesAbstract:Abstract We compare the repeated adiabatic Shear Band Formation that takes place at sufficiently large cutting speeds in a number of materials during high-speed machining operations with the more well-known Formation of a single Shear Band that often takes place at sufficiently large strain rates in dynamic torsion tests on these materials. We show that there are several major differences in the physics of the two deFormation processes. In particular, the Shear stress in machining over the tool-material contact length is not even approximately homogeneous. Additionally, in high-speed machining, the material flow can become convection-dominated, so that the tool can “outrun” the thermal front generated in the workpiece material by the high-strain-rate cutting process. We demonstrate by means of a one-dimensional continuum model that these differences can lead to repeated oscillations in the plastic flow of the workpiece material during high-speed machining, leading to the repeated Formation of adiabatic Shear Bands.
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On repeated adiabatic Shear Band Formation during high-speed machining ☆
International Journal of Plasticity, 2002Co-Authors: Timothy J Burns, Matthew A. DaviesAbstract:Abstract We compare the repeated adiabatic Shear Band Formation that takes place at sufficiently large cutting speeds in a number of materials during high-speed machining operations with the more well-known Formation of a single Shear Band that often takes place at sufficiently large strain rates in dynamic torsion tests on these materials. We show that there are several major differences in the physics of the two deFormation processes. In particular, the Shear stress in machining over the tool-material contact length is not even approximately homogeneous. Additionally, in high-speed machining, the material flow can become convection-dominated, so that the tool can “outrun” the thermal front generated in the workpiece material by the high-strain-rate cutting process. We demonstrate by means of a one-dimensional continuum model that these differences can lead to repeated oscillations in the plastic flow of the workpiece material during high-speed machining, leading to the repeated Formation of adiabatic Shear Bands.
Timothy J Burns - One of the best experts on this subject based on the ideXlab platform.
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on repeated adiabatic Shear Band Formation during high speed machining
International Journal of Plasticity, 2002Co-Authors: Timothy J Burns, Matthew A. DaviesAbstract:Abstract We compare the repeated adiabatic Shear Band Formation that takes place at sufficiently large cutting speeds in a number of materials during high-speed machining operations with the more well-known Formation of a single Shear Band that often takes place at sufficiently large strain rates in dynamic torsion tests on these materials. We show that there are several major differences in the physics of the two deFormation processes. In particular, the Shear stress in machining over the tool-material contact length is not even approximately homogeneous. Additionally, in high-speed machining, the material flow can become convection-dominated, so that the tool can “outrun” the thermal front generated in the workpiece material by the high-strain-rate cutting process. We demonstrate by means of a one-dimensional continuum model that these differences can lead to repeated oscillations in the plastic flow of the workpiece material during high-speed machining, leading to the repeated Formation of adiabatic Shear Bands.
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On repeated adiabatic Shear Band Formation during high-speed machining ☆
International Journal of Plasticity, 2002Co-Authors: Timothy J Burns, Matthew A. DaviesAbstract:Abstract We compare the repeated adiabatic Shear Band Formation that takes place at sufficiently large cutting speeds in a number of materials during high-speed machining operations with the more well-known Formation of a single Shear Band that often takes place at sufficiently large strain rates in dynamic torsion tests on these materials. We show that there are several major differences in the physics of the two deFormation processes. In particular, the Shear stress in machining over the tool-material contact length is not even approximately homogeneous. Additionally, in high-speed machining, the material flow can become convection-dominated, so that the tool can “outrun” the thermal front generated in the workpiece material by the high-strain-rate cutting process. We demonstrate by means of a one-dimensional continuum model that these differences can lead to repeated oscillations in the plastic flow of the workpiece material during high-speed machining, leading to the repeated Formation of adiabatic Shear Bands.
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A Mechanism for Shear Band Formation in the High Strain-Rate Torsion Test
Journal of Applied Mechanics, 1990Co-Authors: Timothy J BurnsAbstract:A moving boundary of rigid unloading, starting from the ends of the thin-walled tubular specimen, is a plausible mechanism for adiabatic Shear Band Formation during the test. The mathematical model is based on a physical model of thermoelastic-plastic flow and a phenomenological Arrhenius model for the plastic flow surface
Stein Sture - One of the best experts on this subject based on the ideXlab platform.
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Shear Band Formation in plane strain experiments of sand
Journal of Geotechnical and Geoenvironmental Engineering, 2000Co-Authors: Khalid A Alshibli, Stein StureAbstract:A series of biaxial (plane strain) experiments were conducted on three sands under low (15 kPa) and high (100 kPa) confining pressure conditions to investigate the effects of specimen density, confining pressure, and sand grain size and shape on the constitutive and stability behavior of granular materials. The three sands used in the experiments were fine-, medium-, and coarse-grained uniform silica sands with rounded, subangular, and angular grains, respectively. Specimen deFormation was readily monitored and analyzed with the help of a grid pattern imprinted on the latex membrane. The overall stress-strain behavior is strongly dependent on the specimen density, confining pressure, sand grain texture, and the resulting failure mode(s). That became evident in different degrees of softening responses at various axial strains. The relationship between the constitutive behavior and the specimens' modes of instability is presented. The failure in all specimens was characterized by two distinct and opposite s...
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Shear Band Formation in plane strain experiments of sand
Journal of Geotechnical and Geoenvironmental Engineering, 2000Co-Authors: Khalid A Alshibli, Stein StureAbstract:A series of biaxial (plane strain) experiments were conducted on three sands under low (15 kPa) and high (100 kPa) confining pressure conditions to investigate the effects of specimen density, confining pressure, and sand grain size and shape on the constitutive and stability behavior of granular materials. The three sands used in the experiments were fine-, medium-, and coarse-grained uniform silica sands with rounded, subangular, and angular grains, respectively. Specimen deFormation was readily monitored and analyzed with the help of a grid pattern imprinted on the latex membrane. The overall stress-strain behavior is strongly dependent on the specimen density, confining pressure, sand grain texture, and the resulting failure mode(s). That became evident in different degrees of softening responses at various axial strains. The relationship between the constitutive behavior and the specimens' modes of instability is presented. The failure in all specimens was characterized by two distinct and opposite Shear Bands. It was found that the measured dilatancy angles increase as the sand grains' angularities and sizes increase. The measured Shear Band inclination angles are also presented and compared with classical Coulomb and Roscoe solutions.