The Experts below are selected from a list of 870 Experts worldwide ranked by ideXlab platform
T. F. Morgeneyer - One of the best experts on this subject based on the ideXlab platform.
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3d damage micromechanisms in polyamide 6 ahead of a severe Notch studied by in situ synchrotron laminography
Macromolecular Chemistry and Physics, 2016Co-Authors: L. Helfen, Yin Cheng, Lucien Laiarinandrasana, Henry Proudhon, Olga Klinkova, Tilo Baumbach, T. F. MorgeneyerAbstract:Micro-damage mechanisms in a semicrystalline polyamide 6 polymer are characterized by in situ synchrotron radiation computed laminography (SRCL) using compact-tension like specimens with a Notch root radius of 0.25 mm. SRCL allows the quantification of cavity nucleation, growth, and coalescence in flat 2 mm thick Notched specimens with a micrometer resolution in 3D (under conditions of severe stress triaxiality) during the in situ loading. The maximum damage occurred at mid-thickness and was located at a small distance ≈ 200 µm from the Notch root. It is shown that damage is distributed in distinct zones, which can be linked to different stress triaxiality states. Penny-shaped cracks are found after some loadings and their diameters are a function of the distance to the Notch root. In a layer of about 33 µm no damage was found. In the adjacent 128 µm layer, penny-shaped cracks are found with diameters of the order of average spherulite sizes (4–6 µm). In the next region, 30–45 µm long cracks are found corresponding to several average spherulite diameters. During propagation, tunnel-like cracks are formed ahead of the main crack. Finally, crack initiation location is found to be largely dependent on the roughness of the Machined Notch surface by comparing two samples with the same loading conditions.
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3D Digital Volume Correlation of Synchrotron Radiation Laminography Images of Ductile Crack Initiation: An Initial Feasibility Study
Experimental Mechanics, 2013Co-Authors: T. F. Morgeneyer, L. Helfen, H. Mubarak, F. HildAbstract:A feasibility study of measuring 3D displacement fields in the bulk during ductile crack initiation via combined Synchrotron Radiation Computed Laminography (SRCL) and Digital Volume Correlation (DVC) is performed. In contrast to tomography, SRCL is a technique that is particularly adapted to obtain three-dimensional (3D) reconstructed volumes of objects that are laterally extended (i.e., in 2 directions) and thin in the third direction, i.e. sheet-like objects. In-situ laminography data of an initiating crack ahead of a Machined Notch are used with a voxel size of 0.7 μm. The natural contrast of the observed 2XXX Al-alloy caused by intermetallic particles and initial porosity is used to measure displacement fields via a global DVC technique assuming a continuous displacement field. An initial performance study is carried out on data of the same undeformed material but after a substantial shift of the laminography rotation axis with respect to the imaged specimen. Volume correlations between different loading steps provide displacement fields that are qualitatively consistent with the remote loading conditions. Computed strain fields display a strain concentration close to the Notch tip.
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3D Digital Volume Correlation of Synchrotron Radiation Laminography images of ductile crack . . .
2013Co-Authors: T. F. Morgeneyer, L. Helfen, H. Mubarak, F. HildAbstract:A feasibility study of measuring 3D displacement fields in the bulk during ductile crack initiation via combined Synchrotron Radiat ion Computed Laminography (SRCL) and Digital Volume Correlation (DVC) is performed. In contrast to Tomography, SRCL is a technique that is particularly adapted to obtain in 3D reconstructed volumes of objects that are laterally extended (i.e., in 2 directions) and thin in the third direction, i.e. sheet-like objects. In-situ laminography data of an initiating crack ahead of a Machined Notch are used with a voxel size of 0.7 µm. The natural contrast of the observed 2XXX Al-alloy caused by intermetallic particles and initial porosity is used to measure displacement fields via a global DVC technique assuming a continuous displacement field. An initial performance study is carried out on data of the same undeformed material but after a substantial shift of the laminography rotation axis with respect to the imaged specimen. Volume correlations between different loading steps provide displacement fields that are qualitatively consistent with the remote loading conditions. Computed strain fields display a strain concentration close to the Notch tip
L. Helfen - One of the best experts on this subject based on the ideXlab platform.
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3d damage micromechanisms in polyamide 6 ahead of a severe Notch studied by in situ synchrotron laminography
Macromolecular Chemistry and Physics, 2016Co-Authors: L. Helfen, Yin Cheng, Lucien Laiarinandrasana, Henry Proudhon, Olga Klinkova, Tilo Baumbach, T. F. MorgeneyerAbstract:Micro-damage mechanisms in a semicrystalline polyamide 6 polymer are characterized by in situ synchrotron radiation computed laminography (SRCL) using compact-tension like specimens with a Notch root radius of 0.25 mm. SRCL allows the quantification of cavity nucleation, growth, and coalescence in flat 2 mm thick Notched specimens with a micrometer resolution in 3D (under conditions of severe stress triaxiality) during the in situ loading. The maximum damage occurred at mid-thickness and was located at a small distance ≈ 200 µm from the Notch root. It is shown that damage is distributed in distinct zones, which can be linked to different stress triaxiality states. Penny-shaped cracks are found after some loadings and their diameters are a function of the distance to the Notch root. In a layer of about 33 µm no damage was found. In the adjacent 128 µm layer, penny-shaped cracks are found with diameters of the order of average spherulite sizes (4–6 µm). In the next region, 30–45 µm long cracks are found corresponding to several average spherulite diameters. During propagation, tunnel-like cracks are formed ahead of the main crack. Finally, crack initiation location is found to be largely dependent on the roughness of the Machined Notch surface by comparing two samples with the same loading conditions.
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3D Digital Volume Correlation of Synchrotron Radiation Laminography Images of Ductile Crack Initiation: An Initial Feasibility Study
Experimental Mechanics, 2013Co-Authors: T. F. Morgeneyer, L. Helfen, H. Mubarak, F. HildAbstract:A feasibility study of measuring 3D displacement fields in the bulk during ductile crack initiation via combined Synchrotron Radiation Computed Laminography (SRCL) and Digital Volume Correlation (DVC) is performed. In contrast to tomography, SRCL is a technique that is particularly adapted to obtain three-dimensional (3D) reconstructed volumes of objects that are laterally extended (i.e., in 2 directions) and thin in the third direction, i.e. sheet-like objects. In-situ laminography data of an initiating crack ahead of a Machined Notch are used with a voxel size of 0.7 μm. The natural contrast of the observed 2XXX Al-alloy caused by intermetallic particles and initial porosity is used to measure displacement fields via a global DVC technique assuming a continuous displacement field. An initial performance study is carried out on data of the same undeformed material but after a substantial shift of the laminography rotation axis with respect to the imaged specimen. Volume correlations between different loading steps provide displacement fields that are qualitatively consistent with the remote loading conditions. Computed strain fields display a strain concentration close to the Notch tip.
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3D Digital Volume Correlation of Synchrotron Radiation Laminography images of ductile crack . . .
2013Co-Authors: T. F. Morgeneyer, L. Helfen, H. Mubarak, F. HildAbstract:A feasibility study of measuring 3D displacement fields in the bulk during ductile crack initiation via combined Synchrotron Radiat ion Computed Laminography (SRCL) and Digital Volume Correlation (DVC) is performed. In contrast to Tomography, SRCL is a technique that is particularly adapted to obtain in 3D reconstructed volumes of objects that are laterally extended (i.e., in 2 directions) and thin in the third direction, i.e. sheet-like objects. In-situ laminography data of an initiating crack ahead of a Machined Notch are used with a voxel size of 0.7 µm. The natural contrast of the observed 2XXX Al-alloy caused by intermetallic particles and initial porosity is used to measure displacement fields via a global DVC technique assuming a continuous displacement field. An initial performance study is carried out on data of the same undeformed material but after a substantial shift of the laminography rotation axis with respect to the imaged specimen. Volume correlations between different loading steps provide displacement fields that are qualitatively consistent with the remote loading conditions. Computed strain fields display a strain concentration close to the Notch tip
Yin Cheng - One of the best experts on this subject based on the ideXlab platform.
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3d damage micromechanisms in polyamide 6 ahead of a severe Notch studied by in situ synchrotron laminography
Macromolecular Chemistry and Physics, 2016Co-Authors: L. Helfen, Yin Cheng, Lucien Laiarinandrasana, Henry Proudhon, Olga Klinkova, Tilo Baumbach, T. F. MorgeneyerAbstract:Micro-damage mechanisms in a semicrystalline polyamide 6 polymer are characterized by in situ synchrotron radiation computed laminography (SRCL) using compact-tension like specimens with a Notch root radius of 0.25 mm. SRCL allows the quantification of cavity nucleation, growth, and coalescence in flat 2 mm thick Notched specimens with a micrometer resolution in 3D (under conditions of severe stress triaxiality) during the in situ loading. The maximum damage occurred at mid-thickness and was located at a small distance ≈ 200 µm from the Notch root. It is shown that damage is distributed in distinct zones, which can be linked to different stress triaxiality states. Penny-shaped cracks are found after some loadings and their diameters are a function of the distance to the Notch root. In a layer of about 33 µm no damage was found. In the adjacent 128 µm layer, penny-shaped cracks are found with diameters of the order of average spherulite sizes (4–6 µm). In the next region, 30–45 µm long cracks are found corresponding to several average spherulite diameters. During propagation, tunnel-like cracks are formed ahead of the main crack. Finally, crack initiation location is found to be largely dependent on the roughness of the Machined Notch surface by comparing two samples with the same loading conditions.
Olga Klinkova - One of the best experts on this subject based on the ideXlab platform.
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3d damage micromechanisms in polyamide 6 ahead of a severe Notch studied by in situ synchrotron laminography
Macromolecular Chemistry and Physics, 2016Co-Authors: L. Helfen, Yin Cheng, Lucien Laiarinandrasana, Henry Proudhon, Olga Klinkova, Tilo Baumbach, T. F. MorgeneyerAbstract:Micro-damage mechanisms in a semicrystalline polyamide 6 polymer are characterized by in situ synchrotron radiation computed laminography (SRCL) using compact-tension like specimens with a Notch root radius of 0.25 mm. SRCL allows the quantification of cavity nucleation, growth, and coalescence in flat 2 mm thick Notched specimens with a micrometer resolution in 3D (under conditions of severe stress triaxiality) during the in situ loading. The maximum damage occurred at mid-thickness and was located at a small distance ≈ 200 µm from the Notch root. It is shown that damage is distributed in distinct zones, which can be linked to different stress triaxiality states. Penny-shaped cracks are found after some loadings and their diameters are a function of the distance to the Notch root. In a layer of about 33 µm no damage was found. In the adjacent 128 µm layer, penny-shaped cracks are found with diameters of the order of average spherulite sizes (4–6 µm). In the next region, 30–45 µm long cracks are found corresponding to several average spherulite diameters. During propagation, tunnel-like cracks are formed ahead of the main crack. Finally, crack initiation location is found to be largely dependent on the roughness of the Machined Notch surface by comparing two samples with the same loading conditions.
Tilo Baumbach - One of the best experts on this subject based on the ideXlab platform.
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3d damage micromechanisms in polyamide 6 ahead of a severe Notch studied by in situ synchrotron laminography
Macromolecular Chemistry and Physics, 2016Co-Authors: L. Helfen, Yin Cheng, Lucien Laiarinandrasana, Henry Proudhon, Olga Klinkova, Tilo Baumbach, T. F. MorgeneyerAbstract:Micro-damage mechanisms in a semicrystalline polyamide 6 polymer are characterized by in situ synchrotron radiation computed laminography (SRCL) using compact-tension like specimens with a Notch root radius of 0.25 mm. SRCL allows the quantification of cavity nucleation, growth, and coalescence in flat 2 mm thick Notched specimens with a micrometer resolution in 3D (under conditions of severe stress triaxiality) during the in situ loading. The maximum damage occurred at mid-thickness and was located at a small distance ≈ 200 µm from the Notch root. It is shown that damage is distributed in distinct zones, which can be linked to different stress triaxiality states. Penny-shaped cracks are found after some loadings and their diameters are a function of the distance to the Notch root. In a layer of about 33 µm no damage was found. In the adjacent 128 µm layer, penny-shaped cracks are found with diameters of the order of average spherulite sizes (4–6 µm). In the next region, 30–45 µm long cracks are found corresponding to several average spherulite diameters. During propagation, tunnel-like cracks are formed ahead of the main crack. Finally, crack initiation location is found to be largely dependent on the roughness of the Machined Notch surface by comparing two samples with the same loading conditions.
