The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Bernard Cabane - One of the best experts on this subject based on the ideXlab platform.

  • Compressive consolidation of strongly aggregated particle gels
    Journal of Rheology, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of particle gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes and discussed the packing-fraction dependence with the particle-scale rearrangements. The two-dimensional simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e., the correlation length of the structure). We observed three stages of compression: (I) Elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multimode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension Df and correlation length ξ start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

  • Compressive consolidation of strongly aggregated colloidal gels
    arXiv: Soft Condensed Matter, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of colloidal gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes, and discussed the packing fraction dependence with the particle scale rearrangements. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e. the correlation length of the structure). We observed three stages of compression: (I) elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multi-mode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension D_f and correlation length \xi start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

  • Compressive consolidation of strongly aggregated particle gels
    Journal of Rheology, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of particle gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes, and discussed the packing fraction dependence with the particle scale rearrangements. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e. the correlation length of the structure). We observed three stages of compression: (I) elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multi-mode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension $D_{\mathrm{f}}$ and correlation length $\xi$ start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

David Rodney - One of the best experts on this subject based on the ideXlab platform.

  • Time-resolved shear transformations in the transient Plastic Regime of sheared amorphous silicon.
    Physical Review E, 2020
    Co-Authors: T. Albaret, Francesca Boioli, David Rodney
    Abstract:

    The accumulation of shear transformations (STs) in space and time is responsible for Plastic deformation in amorphous solids. Here we study the effect of finite strain rates on STs during simulations of athermal shear deformation in an atomistic model of amorphous silicon. We present a time-resolved analysis of STs by mapping the Plastic events identified in the atomistic simulations on a collection of Eshelby inclusions, which are characterized in terms of number, effective volume, lifetime, and orientation. Our analysis led us to distinguish between small and large events. We find that the main effect of a lower strain rate is to allow for a larger number of small events, roughly identified by an effective volume γ_{0}V_{0}

  • time resolved shear transformations in the transient Plastic Regime of sheared amorphous silicon
    Physical Review E, 2020
    Co-Authors: T. Albaret, Francesca Boioli, David Rodney
    Abstract:

    The accumulation of shear transformations (STs) in space and time is responsible for Plastic deformation in amorphous solids. Here we study the effect of finite strain rates on STs during simulations of athermal shear deformation in an atomistic model of amorphous silicon. We present a time-resolved analysis of STs by mapping the Plastic events identified in the atomistic simulations on a collection of Eshelby inclusions, which are characterized in terms of number, effective volume, lifetime, and orientation. Our analysis led us to distinguish between small and large events. We find that the main effect of a lower strain rate is to allow for a larger number of small events, roughly identified by an effective volume ${\ensuremath{\gamma}}_{0}{V}_{0}l20$ \AA{}${}^{3}$, while the number and characteristics of larger events are surprisingly independent of the strain rate. We show that at low strains, the decrease of the stress observed at lower strain rates is mainly due to the excess of small events, while at larger strains, when the glass approaches the yield point where a shear band forms, larger events start to play a role and organize due to their elastic interactions. This phenomenology is compared with the predictions of mesoscale elastoPlastic models. The technique developed here can be used as a systematic tool to analyze Plasticity during molecular dynamics simulations. It can also give valuable information to develop physically grounded mesoscale models of Plasticity, providing quantitative predictions of the mechanical properties of amorphous materials.

Ryohei Seto - One of the best experts on this subject based on the ideXlab platform.

  • Compressive consolidation of strongly aggregated particle gels
    Journal of Rheology, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of particle gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes and discussed the packing-fraction dependence with the particle-scale rearrangements. The two-dimensional simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e., the correlation length of the structure). We observed three stages of compression: (I) Elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multimode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension Df and correlation length ξ start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

  • Compressive consolidation of strongly aggregated colloidal gels
    arXiv: Soft Condensed Matter, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of colloidal gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes, and discussed the packing fraction dependence with the particle scale rearrangements. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e. the correlation length of the structure). We observed three stages of compression: (I) elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multi-mode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension D_f and correlation length \xi start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

  • Compressive consolidation of strongly aggregated particle gels
    Journal of Rheology, 2013
    Co-Authors: Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
    Abstract:

    The compressive yield stress of particle gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes, and discussed the packing fraction dependence with the particle scale rearrangements. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e. the correlation length of the structure). We observed three stages of compression: (I) elastic-dominant Regime; (II) single-mode Plastic Regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multi-mode Plastic Regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension $D_{\mathrm{f}}$ and correlation length $\xi$ start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

B. Venkataraman - One of the best experts on this subject based on the ideXlab platform.

T. Albaret - One of the best experts on this subject based on the ideXlab platform.

  • Time-resolved shear transformations in the transient Plastic Regime of sheared amorphous silicon.
    Physical Review E, 2020
    Co-Authors: T. Albaret, Francesca Boioli, David Rodney
    Abstract:

    The accumulation of shear transformations (STs) in space and time is responsible for Plastic deformation in amorphous solids. Here we study the effect of finite strain rates on STs during simulations of athermal shear deformation in an atomistic model of amorphous silicon. We present a time-resolved analysis of STs by mapping the Plastic events identified in the atomistic simulations on a collection of Eshelby inclusions, which are characterized in terms of number, effective volume, lifetime, and orientation. Our analysis led us to distinguish between small and large events. We find that the main effect of a lower strain rate is to allow for a larger number of small events, roughly identified by an effective volume γ_{0}V_{0}

  • time resolved shear transformations in the transient Plastic Regime of sheared amorphous silicon
    Physical Review E, 2020
    Co-Authors: T. Albaret, Francesca Boioli, David Rodney
    Abstract:

    The accumulation of shear transformations (STs) in space and time is responsible for Plastic deformation in amorphous solids. Here we study the effect of finite strain rates on STs during simulations of athermal shear deformation in an atomistic model of amorphous silicon. We present a time-resolved analysis of STs by mapping the Plastic events identified in the atomistic simulations on a collection of Eshelby inclusions, which are characterized in terms of number, effective volume, lifetime, and orientation. Our analysis led us to distinguish between small and large events. We find that the main effect of a lower strain rate is to allow for a larger number of small events, roughly identified by an effective volume ${\ensuremath{\gamma}}_{0}{V}_{0}l20$ \AA{}${}^{3}$, while the number and characteristics of larger events are surprisingly independent of the strain rate. We show that at low strains, the decrease of the stress observed at lower strain rates is mainly due to the excess of small events, while at larger strains, when the glass approaches the yield point where a shear band forms, larger events start to play a role and organize due to their elastic interactions. This phenomenology is compared with the predictions of mesoscale elastoPlastic models. The technique developed here can be used as a systematic tool to analyze Plasticity during molecular dynamics simulations. It can also give valuable information to develop physically grounded mesoscale models of Plasticity, providing quantitative predictions of the mechanical properties of amorphous materials.