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Hyoung Seop Kim - One of the best experts on this subject based on the ideXlab platform.
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On the phase transformation and dynamic stress-Strain Partitioning of ferrous medium-entropy alloy using experimentation and finite element method
Materialia, 2020Co-Authors: Jae Wung Bae, Jaimyun Jung, Jung Gi Kim, Jeong Min Park, Stefanus Harjo, Takuro Kawasaki, Wanchuck Woo, Hyoung Seop KimAbstract:Abstract Observations based on either side of experiment or modeling often have difficulties in understanding microstructural and mechanical evolutions during deformation, and in application to the macroscopic behavior of materials. In the present study, an integrated experimental-numerical analysis on ferrous medium-entropy alloy (FMEA) was conducted to understand the micromechanical response of the constituent phases in the FMEA at −137 °C. The initial face-centered cubic (FCC) single phase microstructure of the FMEA was transformed to body-centered cubic (BCC) martensite during tensile deformation at −137 °C, resulting in improved low-temperature mechanical properties. The microstructure evolution due to deformation-induced phase transformation mechanism and Strain Partitioning behavior was analyzed using ex-situ electron backscatter diffraction. The mechanical responses related to the stress Partitioning between constituent phases and deformation-induced transformation rate were measured using in-situ neutron diffraction in combination with the nanoindentation analysis. Three-dimensional microstructure volume element based crystal plasticity models were built based on the experimental observations, and the simulation results were in good agreement with the experimental ones. The concurrent analysis by means of the integrated methodology revealed that the dynamic stress–Strain Partitioning process between the FCC and BCC martensite enables the superior Strain hardening capability and the resulting outstanding low-temperature mechanical properties.
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Additional hardening in harmonic structured materials by Strain Partitioning and back stress
Materials Research Letters, 2018Co-Authors: Hyung Keun Park, Kei Ameyama, Jongmyung Yoo, Hyunsang Hwang, Hyoung Seop KimAbstract:Deformation behavior of a harmonic structured material (HSM), core–shell 304L stainless steel, is investigated using micro-digital image correlation (micro-DIC). High Strain-Partitioning between co...
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micromechanical finite element analysis of Strain Partitioning in multiphase medium manganese twip trip steel
Acta Materialia, 2016Co-Authors: Marat I Latypov, Sunmi Shin, Bruno C De Cooman, Hyoung Seop KimAbstract:Abstract In the present contribution, a phenomenological constitutive model of medium manganese steels, in which both twinning-induced (TWIP) and transformation-induced (TRIP) plasticity enhancing mechanisms are activated, is implemented in the finite element framework. The implementation is utilized for the analysis of the full-field Strain Partitioning in dual-phase microstructure maps obtained from electron backscattering diffraction. The results of the finite element analysis suggest that the Strain localization in the studied steel has an alternating character. Specifically, in the low Strain region, most of the externally imposed deformation is accommodated by the initially softer austenite. The higher Strain hardening rate of austenite due to deformation twinning (TWIP effect) and the mechanically-induced transformation to martensite (TRIP effect) results in a shift of the Strain localization to ferrite. This alternating Strain localization is a key feature that distinguishes the medium manganese TWIP+TRIP steel. It is shown that this alternating Strain localization contributes to the superior mechanical behavior of medium manganese TWIP+TRIP steel reported in the literature.
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Micromechanical finite element analysis of Strain Partitioning in multiphase medium manganese TWIP+TRIP steel
Acta Materialia, 2016Co-Authors: Marat I Latypov, Sunmi Shin, Bruno C De Cooman, Hyoung Seop KimAbstract:Abstract In the present contribution, a phenomenological constitutive model of medium manganese steels, in which both twinning-induced (TWIP) and transformation-induced (TRIP) plasticity enhancing mechanisms are activated, is implemented in the finite element framework. The implementation is utilized for the analysis of the full-field Strain Partitioning in dual-phase microstructure maps obtained from electron backscattering diffraction. The results of the finite element analysis suggest that the Strain localization in the studied steel has an alternating character. Specifically, in the low Strain region, most of the externally imposed deformation is accommodated by the initially softer austenite. The higher Strain hardening rate of austenite due to deformation twinning (TWIP effect) and the mechanically-induced transformation to martensite (TRIP effect) results in a shift of the Strain localization to ferrite. This alternating Strain localization is a key feature that distinguishes the medium manganese TWIP+TRIP steel. It is shown that this alternating Strain localization contributes to the superior mechanical behavior of medium manganese TWIP+TRIP steel reported in the literature.
Irmeli Manttari - One of the best experts on this subject based on the ideXlab platform.
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preservation of palaeoproterozoic early svecofennian structures in the orijarvi area sw finland evidence for polyphase Strain Partitioning
Precambrian Research, 2006Co-Authors: Pietari Skyttä, Markku Vaisanen, Irmeli ManttariAbstract:Abstract The predominantly migmatitic Palaeoproterozoic Uusimaa belt preserves early lower-grade Svecofennian structures in the Orijarvi area in SW Finland. This study aims at explaining the deformational history responsible for its preservation and also at defining the age of the early Svecofennian deformation. Detailed structural analysis reveals that the preservation was enabled by polyphase Strain Partitioning, which initiated during the early Svecofennian D2 deformation, ∼1875 Ma ago, as revealed by ion microprobe U–Pb data on zircons from granodioritic and intermediate syn-D2 intrusive dykes. The D2 structures were low-Strain upright folds at high crustal levels and sub-horizontal high-Strain folds at deeper crustal levels. The sub-horizontal D2 structures were refolded into upright folds during the subsequent late Svecofennian D3 deformation, whereas the upright D2 structures behaved as almost rigid blocks that caused Strain Partitioning into high-Strain zones along the block margins. This accounts for the low cumulative Strain in specific parts of the Orijarvi area. Further Strain Partitioning during D4 caused reverse dip-slip movements along regional-scale shear zones. Crustal depth controlled the metamorphic grade during D2, when local migmatisation took place at deep crustal levels. Later metamorphic overprint during D3 deformation is evident from post-D2 growth of sillimanite and a second generation of andalusite. Similarities in the structural patterns between the Orijarvi area and the Tampere-Vammala area (∼100 km to the north) suggest that irrespective of the age of the later overprint, subsequent deformation was localised along the margins of the early formed upright domains, while the low-grade rocks within the domains were preserved.
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Preservation of Palaeoproterozoic early Svecofennian structures in the Orijärvi area, SW Finland—Evidence for polyphase Strain Partitioning
Precambrian Research, 2006Co-Authors: Pietari Skyttä, Markku Vaisanen, Irmeli ManttariAbstract:Abstract The predominantly migmatitic Palaeoproterozoic Uusimaa belt preserves early lower-grade Svecofennian structures in the Orijarvi area in SW Finland. This study aims at explaining the deformational history responsible for its preservation and also at defining the age of the early Svecofennian deformation. Detailed structural analysis reveals that the preservation was enabled by polyphase Strain Partitioning, which initiated during the early Svecofennian D2 deformation, ∼1875 Ma ago, as revealed by ion microprobe U–Pb data on zircons from granodioritic and intermediate syn-D2 intrusive dykes. The D2 structures were low-Strain upright folds at high crustal levels and sub-horizontal high-Strain folds at deeper crustal levels. The sub-horizontal D2 structures were refolded into upright folds during the subsequent late Svecofennian D3 deformation, whereas the upright D2 structures behaved as almost rigid blocks that caused Strain Partitioning into high-Strain zones along the block margins. This accounts for the low cumulative Strain in specific parts of the Orijarvi area. Further Strain Partitioning during D4 caused reverse dip-slip movements along regional-scale shear zones. Crustal depth controlled the metamorphic grade during D2, when local migmatisation took place at deep crustal levels. Later metamorphic overprint during D3 deformation is evident from post-D2 growth of sillimanite and a second generation of andalusite. Similarities in the structural patterns between the Orijarvi area and the Tampere-Vammala area (∼100 km to the north) suggest that irrespective of the age of the later overprint, subsequent deformation was localised along the margins of the early formed upright domains, while the low-grade rocks within the domains were preserved.
Asahiko Taira - One of the best experts on this subject based on the ideXlab platform.
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Possible Strain Partitioning structure between the Kumano fore‐arc basin and the slope of the Nankai Trough accretionary prism
Geochemistry Geophysics Geosystems, 2010Co-Authors: K. M. Martin, Sean P.s. Gulick, Nathan L. Bangs, Gregory F. Moore, Juichiro Ashi, Jin-oh Park, Shin'ichi Kuramoto, Asahiko TairaAbstract:[1] A 12 km wide, 56 km long, three-dimensional (3-D) seismic volume acquired over the Nankai Trough offshore the Kii Peninsula, Japan, images the accretionary prism, fore-arc basin, and subducting Philippine Sea Plate. We have analyzed an unusual, trench-parallel depression (a “notch”) along the seaward edge of the fore-arc Kumano Basin, just landward of the megasplay fault system. This bathymetric feature varies along strike, from a single, steep-walled, ∼3.5 km wide notch in the northeast to a broader, ∼5 km wide zone with several shallower linear depressions in the southwest. Below the notch we found both vertical faults and faults which dip toward the central axis of the depression. Dipping faults appear to have normal offset, consistent with the extension required to form a bathymetric low. Some of these dipping faults may join the central vertical fault(s) at depth, creating apparent flower structures. Offset on the vertical faults is difficult to determine, but the along-strike geometry of these faults makes predominantly normal or thrust motion unlikely. We conclude, therefore, that the notch feature is the bathymetric expression of a transtensional fault system. By considering only the along-strike variability of the megasplay fault, we could not explain a transform feature at the scale of the notch. Strike-slip faulting at the seaward edge of fore-arc basins is also observed in Sumatra and is there attributed to Strain Partitioning due to oblique convergence. The wedge and decollement strength variations which control the location of the fore-arc basins may therefore play a role in the position where an along-strike component of Strain is localized. While the obliquity of convergence in the Nankai Trough is comparatively small (∼15°), we believe it generated the Kumano Basin Edge Fault Zone, which has implications for interpreting local measured stress orientations and suggests potential locations for Strain-Partitioning-related deformation in other subduction zones.
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possible Strain Partitioning structure between the kumano fore arc basin and the slope of the nankai trough accretionary prism
Geochemistry Geophysics Geosystems, 2010Co-Authors: K. M. Martin, Sean P.s. Gulick, Nathan L. Bangs, Gregory F. Moore, Juichiro Ashi, Jin-oh Park, Shin'ichi Kuramoto, Asahiko TairaAbstract:[1] A 12 km wide, 56 km long, three-dimensional (3-D) seismic volume acquired over the Nankai Trough offshore the Kii Peninsula, Japan, images the accretionary prism, fore-arc basin, and subducting Philippine Sea Plate. We have analyzed an unusual, trench-parallel depression (a “notch”) along the seaward edge of the fore-arc Kumano Basin, just landward of the megasplay fault system. This bathymetric feature varies along strike, from a single, steep-walled, ∼3.5 km wide notch in the northeast to a broader, ∼5 km wide zone with several shallower linear depressions in the southwest. Below the notch we found both vertical faults and faults which dip toward the central axis of the depression. Dipping faults appear to have normal offset, consistent with the extension required to form a bathymetric low. Some of these dipping faults may join the central vertical fault(s) at depth, creating apparent flower structures. Offset on the vertical faults is difficult to determine, but the along-strike geometry of these faults makes predominantly normal or thrust motion unlikely. We conclude, therefore, that the notch feature is the bathymetric expression of a transtensional fault system. By considering only the along-strike variability of the megasplay fault, we could not explain a transform feature at the scale of the notch. Strike-slip faulting at the seaward edge of fore-arc basins is also observed in Sumatra and is there attributed to Strain Partitioning due to oblique convergence. The wedge and decollement strength variations which control the location of the fore-arc basins may therefore play a role in the position where an along-strike component of Strain is localized. While the obliquity of convergence in the Nankai Trough is comparatively small (∼15°), we believe it generated the Kumano Basin Edge Fault Zone, which has implications for interpreting local measured stress orientations and suggests potential locations for Strain-Partitioning-related deformation in other subduction zones.
Radu Olaru - One of the best experts on this subject based on the ideXlab platform.
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Strain Partitioning at orogenic contacts during rotation strike slip and oblique convergence paleogene early miocene evolution of the contact between the south carpathians and moesia
Global and Planetary Change, 2013Co-Authors: Csaba Krezsek, Alexandru Lăpădat, Liviu Maţenco, Klaus Arnberger, Victor Barbu, Radu OlaruAbstract:Oblique convergence accompanied by large-scale strike–slip deformation taking place between orogenic units is an inherent feature of highly bended mountain chains. Strain Partitioning during subduction and collision takes place between differently oriented orogenic segments and creates contrasting styles of deformation that may include coeval extension, strike–slip and shortening, in particular when large amounts of rotations are recorded. A typical area is the one connecting the Balkans with East Carpathians along the highly bended South Carpathians Mountains that were affected by large scale Paleogene–Miocene Strain Partitioning at the contact with their lower Moesia unit in what is commonly known as the Getic Depression. We analyse this contact by the means of a number of seismic transects calibrated by exploration wells. The kinematic restoration of these transects is correlated with connecting depth information and with previously published studies. This has allowed the definition of a novel kinematic evolution of the deformation observed in the Getic Depression. This evolution is compatible with the definition of a Paleogene–Early Miocene period of transtensional opening by using strike–slip faults that terminate along horsetail geometries. This transtensional deformation migrates in space and time across the basin and is kinematically connected with the oblique shortening taking place in the eastern part of the Getic Depression and SE/East Carpathians. In particular interesting is the mechanism of transtensional migration E-wards and contractional migration W-wards that took place coevally during the rotation and E-ward translation of the upper Carpathians units along the strike of the Getic Depression. This has been subsequently followed by shortening and transpression during Middle Miocene–Quaternary times that was recorded at the scale of the entire studied area.
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Strain Partitioning at orogenic contacts during rotation, strike–slip and oblique convergence: Paleogene–Early Miocene evolution of the contact between the South Carpathians and Moesia
Global and Planetary Change, 2013Co-Authors: Csaba Krezsek, Alexandru Lăpădat, Liviu Maţenco, Klaus Arnberger, Victor Barbu, Radu OlaruAbstract:Oblique convergence accompanied by large-scale strike–slip deformation taking place between orogenic units is an inherent feature of highly bended mountain chains. Strain Partitioning during subduction and collision takes place between differently oriented orogenic segments and creates contrasting styles of deformation that may include coeval extension, strike–slip and shortening, in particular when large amounts of rotations are recorded. A typical area is the one connecting the Balkans with East Carpathians along the highly bended South Carpathians Mountains that were affected by large scale Paleogene–Miocene Strain Partitioning at the contact with their lower Moesia unit in what is commonly known as the Getic Depression. We analyse this contact by the means of a number of seismic transects calibrated by exploration wells. The kinematic restoration of these transects is correlated with connecting depth information and with previously published studies. This has allowed the definition of a novel kinematic evolution of the deformation observed in the Getic Depression. This evolution is compatible with the definition of a Paleogene–Early Miocene period of transtensional opening by using strike–slip faults that terminate along horsetail geometries. This transtensional deformation migrates in space and time across the basin and is kinematically connected with the oblique shortening taking place in the eastern part of the Getic Depression and SE/East Carpathians. In particular interesting is the mechanism of transtensional migration E-wards and contractional migration W-wards that took place coevally during the rotation and E-ward translation of the upper Carpathians units along the strike of the Getic Depression. This has been subsequently followed by shortening and transpression during Middle Miocene–Quaternary times that was recorded at the scale of the entire studied area.
Marat I Latypov - One of the best experts on this subject based on the ideXlab platform.
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micromechanical finite element analysis of Strain Partitioning in multiphase medium manganese twip trip steel
Acta Materialia, 2016Co-Authors: Marat I Latypov, Sunmi Shin, Bruno C De Cooman, Hyoung Seop KimAbstract:Abstract In the present contribution, a phenomenological constitutive model of medium manganese steels, in which both twinning-induced (TWIP) and transformation-induced (TRIP) plasticity enhancing mechanisms are activated, is implemented in the finite element framework. The implementation is utilized for the analysis of the full-field Strain Partitioning in dual-phase microstructure maps obtained from electron backscattering diffraction. The results of the finite element analysis suggest that the Strain localization in the studied steel has an alternating character. Specifically, in the low Strain region, most of the externally imposed deformation is accommodated by the initially softer austenite. The higher Strain hardening rate of austenite due to deformation twinning (TWIP effect) and the mechanically-induced transformation to martensite (TRIP effect) results in a shift of the Strain localization to ferrite. This alternating Strain localization is a key feature that distinguishes the medium manganese TWIP+TRIP steel. It is shown that this alternating Strain localization contributes to the superior mechanical behavior of medium manganese TWIP+TRIP steel reported in the literature.
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Micromechanical finite element analysis of Strain Partitioning in multiphase medium manganese TWIP+TRIP steel
Acta Materialia, 2016Co-Authors: Marat I Latypov, Sunmi Shin, Bruno C De Cooman, Hyoung Seop KimAbstract:Abstract In the present contribution, a phenomenological constitutive model of medium manganese steels, in which both twinning-induced (TWIP) and transformation-induced (TRIP) plasticity enhancing mechanisms are activated, is implemented in the finite element framework. The implementation is utilized for the analysis of the full-field Strain Partitioning in dual-phase microstructure maps obtained from electron backscattering diffraction. The results of the finite element analysis suggest that the Strain localization in the studied steel has an alternating character. Specifically, in the low Strain region, most of the externally imposed deformation is accommodated by the initially softer austenite. The higher Strain hardening rate of austenite due to deformation twinning (TWIP effect) and the mechanically-induced transformation to martensite (TRIP effect) results in a shift of the Strain localization to ferrite. This alternating Strain localization is a key feature that distinguishes the medium manganese TWIP+TRIP steel. It is shown that this alternating Strain localization contributes to the superior mechanical behavior of medium manganese TWIP+TRIP steel reported in the literature.
