The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform
L C Brinson - One of the best experts on this subject based on the ideXlab platform.
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micromechanical quantification of elastic twinning and slip strain partitioning exhibited by polycrystalline Monoclinic nickel titanium during large uniaxial deformations measured via in situ neutron diffraction
Journal of The Mechanics and Physics of Solids, 2013Co-Authors: Aaron P Stebner, Sven C Vogel, R D Noebe, Thomas A Sisneros, Bjorn Clausen, Donald W Brown, Anita Garg, L C BrinsonAbstract:Abstract We draw upon existing knowledge of twinning and slip mechanics to develop a diffraction analysis model that allows for empirical quantification of individual deformation mechanisms to the macroscopic behaviors of low symmetry and phase transforming crystalline solids. These methods are applied in studying elasticity, accommodation twinning, deformation twinning, and slip through neutron diffraction data of tensile and compressive deformations of Monoclinic NiTi to ~18% true strain. A deeper understanding of tension–compression asymmetry in NiTi is gained by connecting crystallographic calculations of polycrystalline twinning strains with in situ diffraction measurements. Our analyses culminate in empirical, micromechanical quantification of individual elastic, accommodation twinning, deformation twinning, and slip contributions to the total macroscopic stress–strain response of a Monoclinic Material subjected to large deformations. From these results, we find that 20–40% of the total plastic response at high strains is due to deformation twinning and 60–80% due to slip.
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young s modulus evolution and texture based elastic inelastic strain partitioning during large uniaxial deformations of Monoclinic nickel titanium
Acta Materialia, 2013Co-Authors: Aaron P Stebner, Donald W Brown, L C BrinsonAbstract:The authors draw upon recent first-principles calculations of Monoclinic NiTi elastic constants to develop a combined numerical–empirical, texture-based approach for calculating the Young’s modulus of polycrystalline, Monoclinic nickel–titanium specimens. These calculations are carried out for load direction inverse pole figures measured in situ via neutron diffraction during tension–compression deformations to ∼18% true strain, as well as unloading events. As demonstrated by application to this empirical data set, the texture-based approach results in the ability to quantify the evolution of Young’s modulus and to micromechanically partition elastic and inelastic macroscopic strains for the entirety of non-linear and asymmetric uniaxial deformations, a result that had not been achieved previously for a Monoclinic Material.
Aaron P Stebner - One of the best experts on this subject based on the ideXlab platform.
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micromechanical quantification of elastic twinning and slip strain partitioning exhibited by polycrystalline Monoclinic nickel titanium during large uniaxial deformations measured via in situ neutron diffraction
Journal of The Mechanics and Physics of Solids, 2013Co-Authors: Aaron P Stebner, Sven C Vogel, R D Noebe, Thomas A Sisneros, Bjorn Clausen, Donald W Brown, Anita Garg, L C BrinsonAbstract:Abstract We draw upon existing knowledge of twinning and slip mechanics to develop a diffraction analysis model that allows for empirical quantification of individual deformation mechanisms to the macroscopic behaviors of low symmetry and phase transforming crystalline solids. These methods are applied in studying elasticity, accommodation twinning, deformation twinning, and slip through neutron diffraction data of tensile and compressive deformations of Monoclinic NiTi to ~18% true strain. A deeper understanding of tension–compression asymmetry in NiTi is gained by connecting crystallographic calculations of polycrystalline twinning strains with in situ diffraction measurements. Our analyses culminate in empirical, micromechanical quantification of individual elastic, accommodation twinning, deformation twinning, and slip contributions to the total macroscopic stress–strain response of a Monoclinic Material subjected to large deformations. From these results, we find that 20–40% of the total plastic response at high strains is due to deformation twinning and 60–80% due to slip.
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young s modulus evolution and texture based elastic inelastic strain partitioning during large uniaxial deformations of Monoclinic nickel titanium
Acta Materialia, 2013Co-Authors: Aaron P Stebner, Donald W Brown, L C BrinsonAbstract:The authors draw upon recent first-principles calculations of Monoclinic NiTi elastic constants to develop a combined numerical–empirical, texture-based approach for calculating the Young’s modulus of polycrystalline, Monoclinic nickel–titanium specimens. These calculations are carried out for load direction inverse pole figures measured in situ via neutron diffraction during tension–compression deformations to ∼18% true strain, as well as unloading events. As demonstrated by application to this empirical data set, the texture-based approach results in the ability to quantify the evolution of Young’s modulus and to micromechanically partition elastic and inelastic macroscopic strains for the entirety of non-linear and asymmetric uniaxial deformations, a result that had not been achieved previously for a Monoclinic Material.
R. Kienzler - One of the best experts on this subject based on the ideXlab platform.
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Modeling of a Reissner-type plate theory for Monoclinic Material
2018Co-Authors: Patrick Schneider, R. KienzlerAbstract:First a hierarchy of Monoclinic plate theories is derived using the a-priori-assumption free uniform-approximation approach, which is based upon a structured truncation of the elastic potential. An a-priori estimate proves that the so-derived higher-order theories have indeed a higher rate of convergence with respect to the relative thickness of the plate. By the use of a pseudo-reduction approach the number of PDEs to be solved is reduced significantly. The pseudo-reduced first-order theory turns out to be the classical Monoclinic plate theory, whereas, the second-order theory is not determined uniquely by the approach. Uniqueness can be achieved by the introduction of an orthogonal decomposition of higher-order gradients of the in-plane displacement. The final second-order Monoclinic plate theory coincides with the Reissner-Mindlin theory for the special case of isotropic Material.
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A Reissner-type plate theory for Monoclinic Material derived by extending the uniform-approximation technique by orthogonal tensor decompositions of nth-order gradients
Meccanica, 2017Co-Authors: Patrick Schneider, R. KienzlerAbstract:The uniform-approximation approach is an a-priori assumption free structured approach for the derivation of hierarchies of lower-dimensional theories for thin structures with increasing approximation accuracy. In this publication, we derive a second-order consistent plate theory for Monoclinic Material and investigate several theories that arise from the original theory by a pseudo-reduction approach which aims to reduce the number of PDEs that are to solve. A one-variable model that governs only the interior solution is presented and, in addition, an extended two-variable model that also covers edge effects. Since the second introduced variable is a rotation of a vector field, we have to uniquely identify the rotation dependent parts in general gradients of the vector field, which is resolved by the introduction of an orthogonal decomposition. The final two-variable model is equivalent to the Reissner–Mindlin theory for the special case of isotropic Material, whereas the one-variable model is equivalent to the first Reissner PDE. In contrast to this special case, the two-variable model is a coupled system of two PDEs for general Monoclinic Material.
Robert G. Payton - One of the best experts on this subject based on the ideXlab platform.
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green s function for torsional waves in a cylindrically Monoclinic Material
International Journal of Engineering Science, 2005Co-Authors: Kazumi Watanabe, Robert G. PaytonAbstract:Abstract Two exact Green’s functions for impulsive and time-harmonic torsional waves in a Monoclinic Material are presented. The impulsive Green’s function is expressed in the closed form of simple algebraic functions and its wave front shape is a torus with inclined elliptic cross section. The time-harmonic Green’s function is also obtained exactly, but in the form of definite integral. Time development of the wave front for the impulsive wave and amplitude contours for the time-harmonic wave are illustrated.
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Green's function for SH-waves in a cylindrically Monoclinic Material
Journal of the Mechanics and Physics of Solids, 2002Co-Authors: Kazumi Watanabe, Robert G. PaytonAbstract:Green's function for SH-waves in a cylindrically Monoclinic Material is considered for impulsive and time-harmonic sources. Closed form expressions for the Green's function are derived for a few limited values of anisotropic parameters. A very interesting time development of the wave front shape is illustrated and the wave front singularity is discussed for the transient SH-wave. Contours of the displacement amplitude for the time-harmonic wave are also shown.
Donald W Brown - One of the best experts on this subject based on the ideXlab platform.
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micromechanical quantification of elastic twinning and slip strain partitioning exhibited by polycrystalline Monoclinic nickel titanium during large uniaxial deformations measured via in situ neutron diffraction
Journal of The Mechanics and Physics of Solids, 2013Co-Authors: Aaron P Stebner, Sven C Vogel, R D Noebe, Thomas A Sisneros, Bjorn Clausen, Donald W Brown, Anita Garg, L C BrinsonAbstract:Abstract We draw upon existing knowledge of twinning and slip mechanics to develop a diffraction analysis model that allows for empirical quantification of individual deformation mechanisms to the macroscopic behaviors of low symmetry and phase transforming crystalline solids. These methods are applied in studying elasticity, accommodation twinning, deformation twinning, and slip through neutron diffraction data of tensile and compressive deformations of Monoclinic NiTi to ~18% true strain. A deeper understanding of tension–compression asymmetry in NiTi is gained by connecting crystallographic calculations of polycrystalline twinning strains with in situ diffraction measurements. Our analyses culminate in empirical, micromechanical quantification of individual elastic, accommodation twinning, deformation twinning, and slip contributions to the total macroscopic stress–strain response of a Monoclinic Material subjected to large deformations. From these results, we find that 20–40% of the total plastic response at high strains is due to deformation twinning and 60–80% due to slip.
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young s modulus evolution and texture based elastic inelastic strain partitioning during large uniaxial deformations of Monoclinic nickel titanium
Acta Materialia, 2013Co-Authors: Aaron P Stebner, Donald W Brown, L C BrinsonAbstract:The authors draw upon recent first-principles calculations of Monoclinic NiTi elastic constants to develop a combined numerical–empirical, texture-based approach for calculating the Young’s modulus of polycrystalline, Monoclinic nickel–titanium specimens. These calculations are carried out for load direction inverse pole figures measured in situ via neutron diffraction during tension–compression deformations to ∼18% true strain, as well as unloading events. As demonstrated by application to this empirical data set, the texture-based approach results in the ability to quantify the evolution of Young’s modulus and to micromechanically partition elastic and inelastic macroscopic strains for the entirety of non-linear and asymmetric uniaxial deformations, a result that had not been achieved previously for a Monoclinic Material.