The Experts below are selected from a list of 5457 Experts worldwide ranked by ideXlab platform

Morton E Gurtin - One of the best experts on this subject based on the ideXlab platform.

  • Some issues associated with the intermediate space in Single-Crystal Plasticity
    Journal of the Mechanics and Physics of Solids, 2016
    Co-Authors: Morton E Gurtin, B. Daya Reddy
    Abstract:

    Abstract In this study we show that some discussions of finite-deformation Single-Crystal Plasticity are conceptually flawed in their focus on a set referred to as the intermediate configuration. Specifically, we prove that what is usually referred to as the intermediate configuration is not a configuration but instead a vector space that we term the intermediate space. We argue that when applied to Single Crystals this intermediate space represents the lattice.

  • the stored energy of cold work thermal annealing and other thermodynamic issues in Single Crystal Plasticity at small length scales
    International Journal of Plasticity, 2015
    Co-Authors: Lallit Anand, Morton E Gurtin, Daya B Reddy
    Abstract:

    Abstract This paper develops a thermodynamically consistent gradient theory of Single-Crystal Plasticity using the principle of virtual power as a paradigm to develop appropriate balance laws for forces and energy. The resulting theory leads to a system of microscopic force balances, one balance for each slip system, and to an energy balance that accounts for power expended during plastic flow via microscopic forces acting in concert with slip-rates and slip-rate gradients. Central to the theory are an internal energy and entropy, plastic in nature, dependent on densities that account for the accumulation of glide dislocations as well as geometrically necessary dislocations – and that, consequently, represent quantities associated with cold work. Our theory allows us to discuss – within the framework of a gradient theory – the fraction of plastic stress-power that goes into heating, as well as the reduction of the dislocation density in a cold-worked material upon subsequent (or concurrent) thermal annealing.

  • gradient Single Crystal Plasticity within a mises hill framework based on a new formulation of self and latent hardening
    Journal of The Mechanics and Physics of Solids, 2014
    Co-Authors: Morton E Gurtin, Daya B Reddy
    Abstract:

    Abstract This paper develops a theory of rate-independent Single-Crystal Plasticity at small length scales. The theory is thermodynamically consistent, and makes provision for power expenditures resulting from vector and scalar microscopic stresses respectively conjugate to slip rates and their tangential gradients on the individual slip systems. Scalar generalized accumulated slips form the basis for a new hardening relation, which takes account of self- and latent-hardening. The resulting initial-boundary value problem is placed in a variational setting in the form of a global variational inequality.

  • Gradient Single-Crystal Plasticity within a Mises–Hill framework based on a new formulation of self- and latent-hardening
    Journal of the Mechanics and Physics of Solids, 2014
    Co-Authors: Morton E Gurtin, B. Daya Reddy
    Abstract:

    Abstract This paper develops a theory of rate-independent Single-Crystal Plasticity at small length scales. The theory is thermodynamically consistent, and makes provision for power expenditures resulting from vector and scalar microscopic stresses respectively conjugate to slip rates and their tangential gradients on the individual slip systems. Scalar generalized accumulated slips form the basis for a new hardening relation, which takes account of self- and latent-hardening. The resulting initial-boundary value problem is placed in a variational setting in the form of a global variational inequality.

  • a gradient theory of small deformation Single Crystal Plasticity that accounts for gnd induced interactions between slip systems
    Journal of The Mechanics and Physics of Solids, 2011
    Co-Authors: Morton E Gurtin, Nobutada Ohno
    Abstract:

    Abstract This paper develops a gradient theory of Single-Crystal Plasticity based on a system of microscopic force balances, one balance for each slip system, derived from the principle of virtual power, and a mechanical version of the second law that includes, via the microscopic forces, work performed during plastic flow. When combined with thermodynamically consistent constitutive relations the microscopic force balances become nonlocal flow rules for the individual slip systems in the form of partial differential equations requiring boundary conditions. Central ingredients in the theory are densities of (geometrically necessary) edge and screw dislocations, densities that describe the accumulation of dislocations, and densities that characterize forest hardening. The form of the forest densities is based on an explicit kinematical expression for the normal Burgers vector on a slip plane.

Fabrice Richard - One of the best experts on this subject based on the ideXlab platform.

  • identifiability of Single Crystal Plasticity parameters from residual topographies in berkovich nanoindentation on fcc nickel
    Journal of The Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    Abstract The information richness of imprints topographies obtained after Berkovich nanoindentation tests at grain scale is assessed for identifying all or part of the parameters of a Single Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign conducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Meric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between dislocations on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper focuses on the Meric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parameters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for measuring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable solution using an inverse method. For the studied behaviour, the results show that eight of the nine Meric-Cailletaud law parameters can be identified using three topographies.

  • Identifiability of Single Crystal Plasticity parameters from residual topographies in Berkovich nanoindentation on FCC nickel
    Journal of the Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    The information richness of imprints topographies obtained after Berkovich nanoindenta- tion tests at grain scale is assessed for identifying all or part of the parameters of a sin- gle Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign con- ducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Méric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between disloca- tions on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper fo- cuses on the Méric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parame- ters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for mea- suring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable so- lution using an inverse method. For the studied behaviour, the results show that eight of the nine Méric-Cailletaud law parameters can be identified using three topographies.

  • Single Crystal Plasticity parameters identification from residual imprint topography after nano-indentation
    2018
    Co-Authors: Emile Renner, Patrick Delobelle, Yves Gaillard, Fabrice Richard, Fabien Amiot
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and coldworked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analyzing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pileups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modeling of the nano-indentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behavior have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

Patrick Delobelle - One of the best experts on this subject based on the ideXlab platform.

  • identifiability of Single Crystal Plasticity parameters from residual topographies in berkovich nanoindentation on fcc nickel
    Journal of The Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    Abstract The information richness of imprints topographies obtained after Berkovich nanoindentation tests at grain scale is assessed for identifying all or part of the parameters of a Single Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign conducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Meric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between dislocations on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper focuses on the Meric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parameters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for measuring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable solution using an inverse method. For the studied behaviour, the results show that eight of the nine Meric-Cailletaud law parameters can be identified using three topographies.

  • Identifiability of Single Crystal Plasticity parameters from residual topographies in Berkovich nanoindentation on FCC nickel
    Journal of the Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    The information richness of imprints topographies obtained after Berkovich nanoindenta- tion tests at grain scale is assessed for identifying all or part of the parameters of a sin- gle Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign con- ducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Méric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between disloca- tions on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper fo- cuses on the Méric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parame- ters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for mea- suring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable so- lution using an inverse method. For the studied behaviour, the results show that eight of the nine Méric-Cailletaud law parameters can be identified using three topographies.

  • Single Crystal Plasticity parameters identification from residual imprint topography after nano-indentation
    2018
    Co-Authors: Emile Renner, Patrick Delobelle, Yves Gaillard, Fabrice Richard, Fabien Amiot
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and coldworked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analyzing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pileups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modeling of the nano-indentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behavior have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

Emile Renner - One of the best experts on this subject based on the ideXlab platform.

  • identifiability of Single Crystal Plasticity parameters from residual topographies in berkovich nanoindentation on fcc nickel
    Journal of The Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    Abstract The information richness of imprints topographies obtained after Berkovich nanoindentation tests at grain scale is assessed for identifying all or part of the parameters of a Single Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign conducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Meric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between dislocations on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper focuses on the Meric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parameters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for measuring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable solution using an inverse method. For the studied behaviour, the results show that eight of the nine Meric-Cailletaud law parameters can be identified using three topographies.

  • Identifiability of Single Crystal Plasticity parameters from residual topographies in Berkovich nanoindentation on FCC nickel
    Journal of the Mechanics and Physics of Solids, 2020
    Co-Authors: Emile Renner, Patrick Delobelle, Fabien Amiot, Yves Gaillard, A Bourceret, Fabrice Richard
    Abstract:

    The information richness of imprints topographies obtained after Berkovich nanoindenta- tion tests at grain scale is assessed for identifying all or part of the parameters of a sin- gle Crystal Plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign con- ducted on nickel samples. A 3D Crystal Plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Méric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between disloca- tions on different slip systems. This makes imprints topographies very good candidates to provide information for the Single Crystal parameters identification. The present paper fo- cuses on the Méric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parame- ters identification using a Crystal Plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for mea- suring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable so- lution using an inverse method. For the studied behaviour, the results show that eight of the nine Méric-Cailletaud law parameters can be identified using three topographies.

  • Single Crystal Plasticity parameters identification from residual imprint topography after nano-indentation
    2018
    Co-Authors: Emile Renner, Patrick Delobelle, Yves Gaillard, Fabrice Richard, Fabien Amiot
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and coldworked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analyzing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pileups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modeling of the nano-indentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behavior have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

  • Sensitivity of the residual topography to Single Crystal Plasticity parameters in Berkovich nanoindentation on FCC nickel
    International Journal of Plasticity, 2016
    Co-Authors: Emile Renner, Fabien Amiot, Yves Gaillard, Fabrice Richard, Patrick Delobelle
    Abstract:

    Fundamental deformation mechanisms of FCC materials under indentation have been probed at the grain scale. Experimental tests have been conducted on large-grained annealed and cold-worked polyCrystalline nickel samples with a Berkovich indenter. Indentation axes have been chosen to be close to the three main Crystallographic directions [001], [101] and [111]. Pile-ups and slip traces have been revealed around the residual imprints by analysing topographic measurements obtained by atomic force microscopy. It is shown that the indenter orientation in each indentation plane drives pile-ups and slip traces which in turn contain precious information about the Crystallographic orientation and the hardening state of the studied grain. Imprint topographies after pile-up formation therefore carry information that one can exploit to assess some intrinsic material properties at the grain scale. A 3D finite element modelling of the nanoindentation test at the grain scale has been developed, making use of Crystal Plasticity constitutive laws. Six different virtual materials having the same macroscopic behaviour have been built. The simulation results show a good agreement with experimental tests and also a great pile-up sensitivity to interaction matrix components. These results pave the way to the interaction matrix identification using an inverse finite element method.

D.j. Lloyd - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Surface Roughening in AA6111 Automotive Sheet Under Pure Bending
    Metallurgical and Materials Transactions A, 2015
    Co-Authors: Y. Shi, H. Jin, P. Z. Zhao, D.j. Lloyd
    Abstract:

    The finite element method is used to numerically simulate the topographic development in an aluminum sheet, AA6111, under pure bending. The measured electron backscatter diffraction data are directly incorporated into the finite element model, and the constitutive response at an integration point is described by the Single Crystal Plasticity theory. The effects of strain-rate sensitivity, work hardening, and imposed initial surface roughness on surface roughening are studied. It is found that the grains in top surface layers of the sheet play a big role in controlling the outer surface roughness due to the strain gradient across sheet thickness in bending, while the grain size and texture of the surface layers have a direct impact on finishing surface qualities.

  • Analysis of ridging in ferritic stainless steel sheet
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006
    Co-Authors: H. Jin, Y. Shi, D.j. Lloyd
    Abstract:

    The finite element method is used to numerically simulate the development of ridging/roping in ferritic stainless steel sheet under stretching. The measured electron backscattered diffraction (EBSD) data (grain orientations and their spatial distributions) are directly incorporated into the finite element model and the constitutive response at an integration point is described by the Single Crystal Plasticity theory. The effects of spatial orientation distribution, imposed deformation path, and inhomogeneous deformation within individual grains on the roping are discussed. It is found that the initial texture and its spatial distribution are the predominant factors for the development of ridging.

  • Analysis of surface roughening in AA6111 automotive sheet
    Acta Materialia, 2004
    Co-Authors: D.j. Lloyd
    Abstract:

    The finite element method is used to numerically simulate the topographic development in an aluminium sheet, AA6111, under stretching. The measured electron backscatter diffraction (EBSD) data are directly incorporated into the finite element model and the constitutive response at an integration point is described by the Single Crystal Plasticity theory. The effect on surface roughening of sample geometry, strain rate sensitivity, work hardening, imposed deformation path, as well as the EBSD step size, spatial orientation distribution and inhomogeneous deformation within individual grains are discussed. It is concluded that surface roughening is controlled by the spatial distribution of grain orientations through the thickness of the specimen.

  • Analysis of roping in AA6111 automotive sheet
    Acta Materialia, 2003
    Co-Authors: D.j. Lloyd, A. Bosland, H. Jin, S.r. Macewen
    Abstract:

    Abstract The finite element method is used to numerically simulate the development of roping in an aluminium sheet AA6111 under stretching. The measured EBSD data are directly incorporated into the finite element model and the constitutive response at an integration point is described by the Single Crystal Plasticity theory. The effects of spatial orientation distribution, imposed deformation path, loading direction, and inhomogeneous deformation within individual grains on the roping are discussed. Correlation between roping and individual texture components is also explored.