The Experts below are selected from a list of 26814 Experts worldwide ranked by ideXlab platform
Egidio Rizzi - One of the best experts on this subject based on the ideXlab platform.
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on the consequences of the adoption of the zaremba jaumann Objective Stress Rate in fem codes
Archives of Computational Methods in Engineering, 2016Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
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On the Consequences of the Adoption of the Zaremba–Jaumann Objective Stress Rate in FEM Codes
Archives of Computational Methods in Engineering, 2014Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
Jacob Fish - One of the best experts on this subject based on the ideXlab platform.
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On the equivalence between the multiplicative hyper-elasto-plasticity and the additive hypo-elasto-plasticity based on the modified kinetic logarithmic Stress Rate
Computer Methods in Applied Mechanics and Engineering, 2018Co-Authors: Yang Jiao, Jacob FishAbstract:Abstract In two theorems presented herein, we prove and subsequently demonstRate in several numerical examples involving homogeneous deformation that for isotropic materials, hyper-elasto-plasticity models based on the multiplicative decomposition of the deformation gradient coincide with an additive hypo-elasto-plasticity model (see Section 3.2) that employs the spin tensor based on the modified kinetic logarithmic Rate. In the absence of strain-induced anisotropy (characterized by kinematic hardening herein), this Objective Stress Rate coincides with the kinetic logarithmic Rate recently developed by Jiao and Fish, 2017. We also show that other well-known additive decomposition models, such as those based on the Jaumann and logarithmic Rates, may considerably deviate from the multiplicative model.
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Finite deformation plasticity based on the additive split of the Rate of deformation and hyperelasticity
Computer Methods in Applied Mechanics and Engineering, 2000Co-Authors: Jacob Fish, Kamlun ShekAbstract:Abstract Finite deformation plasticity formulation based on additive split of Rate of deformation and hyperelasticity is presented. This approach is valid for finite elastic and plastic strains, while rendering the choice and numerical integration of Objective Stress Rates superfluous as the results are automatically Objective. For small elastic strains our method reduces to the classical hypoelastic-corotational formulation provided that the Dienes Objective Stress Rate is employed, while in the absence of inelastic deformation it coincides with the hyper-elastic formulation. The validity of the model has been examined on four test problems and the numerical results were found to be in good agreement with either the exact solution or experimental data.
Luca Gambirasio - One of the best experts on this subject based on the ideXlab platform.
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on the consequences of the adoption of the zaremba jaumann Objective Stress Rate in fem codes
Archives of Computational Methods in Engineering, 2016Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
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On the Consequences of the Adoption of the Zaremba–Jaumann Objective Stress Rate in FEM Codes
Archives of Computational Methods in Engineering, 2014Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
Guido Chiantoni - One of the best experts on this subject based on the ideXlab platform.
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on the consequences of the adoption of the zaremba jaumann Objective Stress Rate in fem codes
Archives of Computational Methods in Engineering, 2016Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
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On the Consequences of the Adoption of the Zaremba–Jaumann Objective Stress Rate in FEM Codes
Archives of Computational Methods in Engineering, 2014Co-Authors: Luca Gambirasio, Guido Chiantoni, Egidio RizziAbstract:This paper deals with a particular issue of computational mechanics in main FEM codes nowadays available, i.e. the outcomes of implementations of large strain constitutive models based on the adoption of so-called Objective Stress Rates, in order to satisfy objectivity requirements. The point here is that of directly inquiring whether well-known incoherencies due to the adoption of the Zaremba–Jaumann Objective Stress Rate may manifest themselves when the most used elastic and elastoplastic constitutive models are adopted. The present investigation aims at providing a comprehensive review of the theoretical aspects and at developing an informed knowledge to final users of FEM codes, in terms of exposing which constitutive models and FEM implementations may be affected by Zaremba–Jaumann Objective Stress Rate induced incoherencies. Towards this end, local FEM simple shear tests are explored and clearly show that kinematic cases characterized by a non zero spin may be heavily affected by oscillatory incoherencies, which arise for expected cases, i.e. Cauchy Stress responses, but also for other less expected cases, i.e. strain responses, whether they are total, elastic or plastic. Beyond local tests, structural simple shear tests are also performed and show as well that oscillatory incoherencies found in local simple shear tests may heavily influence the overall structural outcomes. A non-secondary target of the paper is that of reviewing the relevant scientific and technical literature about Objective Stress Rates, by critically analyzing correlated issues and proposed solutions, considering scientific contributions spanning over a century, keeping specific attention to the treatment of the Zaremba–Jaumann Objective Stress Rate and to the possible flaws related to its adoption.
Yang Jiao - One of the best experts on this subject based on the ideXlab platform.
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On the equivalence between the multiplicative hyper-elasto-plasticity and the additive hypo-elasto-plasticity based on the modified kinetic logarithmic Stress Rate
Computer Methods in Applied Mechanics and Engineering, 2018Co-Authors: Yang Jiao, Jacob FishAbstract:Abstract In two theorems presented herein, we prove and subsequently demonstRate in several numerical examples involving homogeneous deformation that for isotropic materials, hyper-elasto-plasticity models based on the multiplicative decomposition of the deformation gradient coincide with an additive hypo-elasto-plasticity model (see Section 3.2) that employs the spin tensor based on the modified kinetic logarithmic Rate. In the absence of strain-induced anisotropy (characterized by kinematic hardening herein), this Objective Stress Rate coincides with the kinetic logarithmic Rate recently developed by Jiao and Fish, 2017. We also show that other well-known additive decomposition models, such as those based on the Jaumann and logarithmic Rates, may considerably deviate from the multiplicative model.
