The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
D L Atherton - One of the best experts on this subject based on the ideXlab platform.
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Residual and compressive stress effects on tensor magnetization
IEEE Transactions on Magnetics, 2002Co-Authors: D L AthertonAbstract:We measured tensor hysteresis loops for a 25.4 mm Steel Cube with compressive stress applied orthogonal to the field, and studied the repeatability of compressive stress effects in terms of the maximum magnetization and differential susceptibility amplitudes. The nonrepeatability of results and anomalous low stress behavior can be attributed to stress hysteresis, specifically to residual stress.
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Magnetization vector directions in a Steel Cube'
2000 IEEE International Magnetics Conference (INTERMAG), 2000Co-Authors: D L AthertonAbstract:Summary form only given. The complete presentation was not made available for publication as part of the conference proceedings.
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effects of compressive stress on a Steel Cube using tensor magnetization and magnetostriction analysis
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: F Liorzou, D L AthertonAbstract:Abstract Measurements of the effects of a compressive stress on magnetization and magnetostriction loops of a cubic sample from a Steel pipe are presented. The compressive stress was applied perpendicularly to the magnetic field and, in order to take account of the anisotropy of the sample, measurements were performed in all three orthogonal directions with field applied successively parallel to each direction of the Cube edges. This gives rise to 3×3 matrices defining the magnetization and magnetostriction tensors. Analysis of each element of the tensors enabled, firstly, the initial preferential orientation of the magnetic domains due to the texture to be identified and, secondly, permitted us to follow the changes in the bulk easy axis induced when the compressive stress was applied. Valuable information about these changes in the domain arrangements was obtained from analysis of the off-diagonal elements of the magnetization tensor.
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tensor magnetic hysteresis loop measurements of a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, T W Krause, P Weyman, D L AthertonAbstract:Abstract The change in magnetic moment of a 25.4 mm Steel Cube sample was measured in three orthogonal directions with fields up to magnetic saturation applied in each of the three Cube directions. An analysis of the diagonal components of the resulting 3 × 3 tensor indicated the relative magnetic easy axis amongst three three directions measured. Additional information on the magnetization processes was obtained from an analysis of the off-diagonal changes in the magnetic moment tensor. Hysteresis was also observed in these off-diagonal loops. A net magnetization vector of magnitude M was considered. Deviations of magnetization components from linearity along the diagonal directions, Δ M il were related to the off-diagonal components, M iJ and M iK , by the simple relation Δ M iI ≈ ± ( M iJ 2 + M iK 2 )/2 M , where i is the field direction x , y , or z and I , J , and K cyclic coordinates X , Y , and Z indicating the magnetization components measured by coils X , Y , and Z , respectively. Changes in the off-diagonal components were associated with various field dependent magnetization processes such as domain wall motion and domain vector rotation. The asymmetry of the magnetic hysteresis loop tensor is associated with either a texture of the material or the existence of internal stresses.
D.l. Atherton - One of the best experts on this subject based on the ideXlab platform.
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effect of compressive stress on the reversible and irreversible differential magnetic susceptibility of a Steel Cube
Journal of Magnetism and Magnetic Materials, 2000Co-Authors: D.l. AthertonAbstract:Tensor hysteresis loops with minor loops are measured for a 25.4 mm line pipe Steel Cube while compressive stresses are applied successively in the directions orthogonal to the applied field. The reversible and irreversible differential magnetic susceptibilities for each element are derived and the effects of compressive stress are studied.
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Magnetization vector directions in a Steel Cube
IEEE Transactions on Magnetics, 2000Co-Authors: D.l. AthertonAbstract:Tensor magnetic hysteresis loops are measured for a pipeline Steel Cube. The amplitude and direction of total magnetization are calculated as the magnetic field is applied in each of the three Cube directions. The results show that the total magnetization remains in the same direction over a large magnetization range while the applied field increases and approaches the magnetic field direction when the field becomes very strong. This proves that the magnetizing process has two stages. One is domain wall motion, for which the magnetization direction remains constant, another is magnetization rotation when the magnetization rotates toward the direction of the applied field.
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Effects of Compressive Stress on Magnetization Components of a Line Pipe Steel Cube
Research in Nondestructive Evaluation, 2000Co-Authors: D.l. AthertonAbstract:Tensor hysteresis loops are measured for a pipeline Steel Cube while compressive stresses are applied orthogonally to the applied field direction. Total magnetization vectors are calculated with the applied magnetic field in each of the three Cube directions. The magnetization components are compared and analyzed for different applied stresses.
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tensor magnetostriction loops for a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, D.l. Atherton, L Clapham, T W KrauseAbstract:Abstract Tensor magnetostriction loops were measured for a 25 mm Steel Cube. The volume magnetostriction of the Cube was calculated for the magnetic field applied in three orthogonal directions parallel to the edge directions of the Cube. The tensor magnetostriction loops are interpreted in terms of domain wall motion and magnetization vector rotation, as well as the existence of a magnetic easy axis in the sample, which is evidenced by the asymmetry of the tensor magnetostriction loops. The relative magnetic easy axis determined from the tensor magnetostriction loops is consistent with that determined from the tensor magnetic hysteresis loops measured previously. A new parameter termed magnetic Poisson's ratio is introduced to describe the relative dimensional changes in the longitudinal and transverse directions with respect to the applied field directions.
T W Krause - One of the best experts on this subject based on the ideXlab platform.
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tensor magnetostriction loops for a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, D.l. Atherton, L Clapham, T W KrauseAbstract:Abstract Tensor magnetostriction loops were measured for a 25 mm Steel Cube. The volume magnetostriction of the Cube was calculated for the magnetic field applied in three orthogonal directions parallel to the edge directions of the Cube. The tensor magnetostriction loops are interpreted in terms of domain wall motion and magnetization vector rotation, as well as the existence of a magnetic easy axis in the sample, which is evidenced by the asymmetry of the tensor magnetostriction loops. The relative magnetic easy axis determined from the tensor magnetostriction loops is consistent with that determined from the tensor magnetic hysteresis loops measured previously. A new parameter termed magnetic Poisson's ratio is introduced to describe the relative dimensional changes in the longitudinal and transverse directions with respect to the applied field directions.
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tensor magnetic hysteresis loop measurements of a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, T W Krause, P Weyman, D L AthertonAbstract:Abstract The change in magnetic moment of a 25.4 mm Steel Cube sample was measured in three orthogonal directions with fields up to magnetic saturation applied in each of the three Cube directions. An analysis of the diagonal components of the resulting 3 × 3 tensor indicated the relative magnetic easy axis amongst three three directions measured. Additional information on the magnetization processes was obtained from an analysis of the off-diagonal changes in the magnetic moment tensor. Hysteresis was also observed in these off-diagonal loops. A net magnetization vector of magnitude M was considered. Deviations of magnetization components from linearity along the diagonal directions, Δ M il were related to the off-diagonal components, M iJ and M iK , by the simple relation Δ M iI ≈ ± ( M iJ 2 + M iK 2 )/2 M , where i is the field direction x , y , or z and I , J , and K cyclic coordinates X , Y , and Z indicating the magnetization components measured by coils X , Y , and Z , respectively. Changes in the off-diagonal components were associated with various field dependent magnetization processes such as domain wall motion and domain vector rotation. The asymmetry of the magnetic hysteresis loop tensor is associated with either a texture of the material or the existence of internal stresses.
Y Yu - One of the best experts on this subject based on the ideXlab platform.
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tensor magnetostriction loops for a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, D.l. Atherton, L Clapham, T W KrauseAbstract:Abstract Tensor magnetostriction loops were measured for a 25 mm Steel Cube. The volume magnetostriction of the Cube was calculated for the magnetic field applied in three orthogonal directions parallel to the edge directions of the Cube. The tensor magnetostriction loops are interpreted in terms of domain wall motion and magnetization vector rotation, as well as the existence of a magnetic easy axis in the sample, which is evidenced by the asymmetry of the tensor magnetostriction loops. The relative magnetic easy axis determined from the tensor magnetostriction loops is consistent with that determined from the tensor magnetic hysteresis loops measured previously. A new parameter termed magnetic Poisson's ratio is introduced to describe the relative dimensional changes in the longitudinal and transverse directions with respect to the applied field directions.
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tensor magnetic hysteresis loop measurements of a Steel Cube
Journal of Magnetism and Magnetic Materials, 1997Co-Authors: Y Yu, T W Krause, P Weyman, D L AthertonAbstract:Abstract The change in magnetic moment of a 25.4 mm Steel Cube sample was measured in three orthogonal directions with fields up to magnetic saturation applied in each of the three Cube directions. An analysis of the diagonal components of the resulting 3 × 3 tensor indicated the relative magnetic easy axis amongst three three directions measured. Additional information on the magnetization processes was obtained from an analysis of the off-diagonal changes in the magnetic moment tensor. Hysteresis was also observed in these off-diagonal loops. A net magnetization vector of magnitude M was considered. Deviations of magnetization components from linearity along the diagonal directions, Δ M il were related to the off-diagonal components, M iJ and M iK , by the simple relation Δ M iI ≈ ± ( M iJ 2 + M iK 2 )/2 M , where i is the field direction x , y , or z and I , J , and K cyclic coordinates X , Y , and Z indicating the magnetization components measured by coils X , Y , and Z , respectively. Changes in the off-diagonal components were associated with various field dependent magnetization processes such as domain wall motion and domain vector rotation. The asymmetry of the magnetic hysteresis loop tensor is associated with either a texture of the material or the existence of internal stresses.
Philip L. Marston - One of the best experts on this subject based on the ideXlab platform.
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Circular synthetic aperture sonar images and aspect dependent spectral properties of solid elastic Cubes
Journal of the Acoustical Society of America, 2016Co-Authors: Viktor Bollen, Philip L. Marston, Daniel S. PlotnickAbstract:While Cubes may not be commonly found underwater, studying their aspect and material-dependent backscattering mechanisms may be useful in leads to understanding the scattering physics of other objects. Two solid Cubes, made of either Steel and or brass, were insonified in water using a circular synthetic aperture sonar (CSAS) system; Fourier based techniques were used to reconstruct target images. Identifiable backscattering mechanisms include edge-diffraction and elastic responses. Rayleigh waves, a class of surface elastic waves, are excited near a material specific incident angle (Rayleigh angle) that depends on the material of the Cube. Those waves may retroreflect from the edges of the Cube’s facee edges of the Cube’s face in such a way as to enhance backscattering [K. Gipson and P. L. Marston, J. Acoust. Soc. Am. 105, 700-710 (1998)]. The Steel Cube displayed a strong Rayleigh wave response, easily visible in CSAS images; for the smaller brass Cube that said mechanism was relatively subtle. Aspect d...
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Circular synthetic aperture sonar images of backscattering enhancements on solid elastic Cubes due to Rayleigh waves and other mechanisms
Journal of the Acoustical Society of America, 2016Co-Authors: Viktor Bollen, Daniel S. Plotnick, Philip L. MarstonAbstract:Aspect dependent backscattering enhancement mechanisms aid in detecting and identifying underwater objects. This work examines enhancement mechanisms on a solid metal Cube observed in acoustic images, emphasizing Rayleigh type surface waves that undergo retroreflection at the corners of the face of the Cube [K. Gipson and P. L. Marston, J. Acoust. Soc. Am. 105, 700–710 (1998)]. Backscattering from a Steel Cube insonified in water was measured using a circular synthetic aperture sonar system. Image reconstruction was performed using Fourier based algorithms. Rayleigh waves are launched on a face of the Cube when the local incident angle is equal to the Rayleigh coupling angle. The presence of four right-angle retroreflectors on each face means that multiple reverberations of this wave are observed. In reconstructed images of the Cube, the Rayleigh wave mechanism is responsible for some of the brightest features. If the relative orientation of the circular aperture and the Cube is such that specular glints ...
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Backscattering enhancements due to retroreflection of ultrasonic leaky Rayleigh waves at corners of solid elastic Cubes in water
Journal of the Acoustical Society of America, 1999Co-Authors: Karen Gipson, Philip L. MarstonAbstract:Backscattering enhancements can be important for interpreting acoustical images of scatterers. Experiments were performed on a solid stainless Steel Cube in water in order to investigate a significant mechanism for producing a large backscattered signal. Enhanced high-frequency backscattering is observed when the block is rotated such that the incident acoustic wave strikes one of its flat surfaces in the vicinity of the coupling angle for launching a leaky Rayleigh wave at the Steel–water interface. This enhancement can be explained as a retroreflection of the leaky wave at a corner of the block, which results in a reversal of the incident wave vector and thus produces a large backscattered signal. The magnitude of the peak backscattered pressure is approximated using a convolution formulation [P. L. Marston, J. Acoust. Soc. Am. 97, 34–41 (1995)]. Observed backscattering enhancements support the validity of the convolution formulation to approximate the general magnitude of the peak pressure, as well as ...