Material instabilities and their role for the initiation of boudinage and folding structures

Manolis Veveakis, M Peters, T. Poulet, Ali Karrech, M Herwegh, Klaus Regenauer-Lieb

    Research output: Contribution to conferenceAbstract

    Abstract

    Localized phenomena, such as pinch-and-swell boudinage or localized folds, are usually interpreted to arise from viscosity contrasts. These are caused by structural heterogeneities, such as geometric or material imperfections. An alternative possibility for strain localization exists in material science, where dynamic localization emerges out of a steady state for a given critical set of material parameters and loading rates (Montési and Zuber, 2002). In our contribution, we will investigate the conditions under which this type of instabilities triggers localized deformation. Moreover, we discuss whether geological materials necessarily require structural heterogeneities, such as weak seeds, in order to generate aforementioned localized structures. We set up a random distribution of grain sizes in a layer embedded in a matrix with a diffusion creep rheology. Deformation within the layer is accommodated by dislocation and diffusion creep as end member deformation mechanism. The grain size evolution follows the paleowattmeter scaling relationship for calcite creep (Austin and Evans, 2007), which is controlled by thermo-mechanical feedbacks (Herwegh et al., 2014). During the first strain increments in the numerical simulation, the layer establishes a viscous steady state, which is the systems' response to optimize energy following the paleowattmeter (Herwegh et al., 2014). With further loading, localization interestingly arises out of a homogeneous state. We will demonstrate the robustness of this numerical solution by identifying the natural mode shapes and frequencies of the simulated structure and material parameters, including geometric imperfections (Rudnicki and Rice, 1975). This technique aims at the determination of the spatial manifestation of the instability pattern (Peters et al., in review). The eigenvalues are thought to represent the nodal points, where the onset of (visco)-elasto-plastic localization can initiate in the structure (Rudnicki and Rice, 1975). The eigenmodes appear as sinusoidal vibrations with geometry- and material parameter-specific natural modal frequencies and shapes. In a next step, the eigenmodes are perturbed and superposed to the initial conditions. We observe that this pattern of perturbations guides the ultimate material bifurcation. Boudinage and folding can therefore be seen as either a pure geometric problem or a fundamental material bifurcation, which evolves out of homogeneous state. The latter class offers the great possibility to extract fundamental material parameters out of localized structures directly from field observations. REFERENCES Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research, 119. Montési, L.G.J. and Zuber, M.T. (2002). A unified description of localization for application to large-scale tectonics. Journal of Geophysical Research, 107. Peters, M., Veveakis, M., Poulet, T., Karrech, A., Herwegh, M. and Regenauer-Lieb Klaus (in review). Boudinage as a material instability of elasto-visco-plastic rocks. Submitted to Journal of Structural Geology. Rudnicki, J. W., Rice, J. R. (1975). Conditions for the localization of deformation in pressure-sensitive dilatant materials. Journal of Mechanics and Physics of Solids, 23.
    Original languageEnglish
    Publication statusPublished - 2015
    EventEuropean Geosciences Union, General Assembly 2015 - Vienna, Austria
    Duration: 12 Apr 201517 Apr 2015
    http://www.egu2015.eu/

    Conference

    ConferenceEuropean Geosciences Union, General Assembly 2015
    CountryAustria
    CityVienna
    Period12/04/1517/04/15
    Internet address

    Fingerprint

    boudinage
    folding
    creep
    rice
    grain size
    plastic
    bifurcation
    material
    structural geology
    deformation mechanism
    eigenvalue
    swell
    rheology
    dislocation
    mechanics
    vibration
    physics
    calcite
    viscosity
    thermodynamics

    Cite this

    Veveakis, M., Peters, M., Poulet, T., Karrech, A., Herwegh, M., & Regenauer-Lieb, K. (2015). Material instabilities and their role for the initiation of boudinage and folding structures. Abstract from European Geosciences Union, General Assembly 2015, Vienna, Austria.
    Veveakis, Manolis ; Peters, M ; Poulet, T. ; Karrech, Ali ; Herwegh, M ; Regenauer-Lieb, Klaus. / Material instabilities and their role for the initiation of boudinage and folding structures. Abstract from European Geosciences Union, General Assembly 2015, Vienna, Austria.
    @conference{5d64c8d7566d4f9f98496bf14b1bc588,
    title = "Material instabilities and their role for the initiation of boudinage and folding structures",
    abstract = "Localized phenomena, such as pinch-and-swell boudinage or localized folds, are usually interpreted to arise from viscosity contrasts. These are caused by structural heterogeneities, such as geometric or material imperfections. An alternative possibility for strain localization exists in material science, where dynamic localization emerges out of a steady state for a given critical set of material parameters and loading rates (Mont{\'e}si and Zuber, 2002). In our contribution, we will investigate the conditions under which this type of instabilities triggers localized deformation. Moreover, we discuss whether geological materials necessarily require structural heterogeneities, such as weak seeds, in order to generate aforementioned localized structures. We set up a random distribution of grain sizes in a layer embedded in a matrix with a diffusion creep rheology. Deformation within the layer is accommodated by dislocation and diffusion creep as end member deformation mechanism. The grain size evolution follows the paleowattmeter scaling relationship for calcite creep (Austin and Evans, 2007), which is controlled by thermo-mechanical feedbacks (Herwegh et al., 2014). During the first strain increments in the numerical simulation, the layer establishes a viscous steady state, which is the systems' response to optimize energy following the paleowattmeter (Herwegh et al., 2014). With further loading, localization interestingly arises out of a homogeneous state. We will demonstrate the robustness of this numerical solution by identifying the natural mode shapes and frequencies of the simulated structure and material parameters, including geometric imperfections (Rudnicki and Rice, 1975). This technique aims at the determination of the spatial manifestation of the instability pattern (Peters et al., in review). The eigenvalues are thought to represent the nodal points, where the onset of (visco)-elasto-plastic localization can initiate in the structure (Rudnicki and Rice, 1975). The eigenmodes appear as sinusoidal vibrations with geometry- and material parameter-specific natural modal frequencies and shapes. In a next step, the eigenmodes are perturbed and superposed to the initial conditions. We observe that this pattern of perturbations guides the ultimate material bifurcation. Boudinage and folding can therefore be seen as either a pure geometric problem or a fundamental material bifurcation, which evolves out of homogeneous state. The latter class offers the great possibility to extract fundamental material parameters out of localized structures directly from field observations. REFERENCES Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research, 119. Mont{\'e}si, L.G.J. and Zuber, M.T. (2002). A unified description of localization for application to large-scale tectonics. Journal of Geophysical Research, 107. Peters, M., Veveakis, M., Poulet, T., Karrech, A., Herwegh, M. and Regenauer-Lieb Klaus (in review). Boudinage as a material instability of elasto-visco-plastic rocks. Submitted to Journal of Structural Geology. Rudnicki, J. W., Rice, J. R. (1975). Conditions for the localization of deformation in pressure-sensitive dilatant materials. Journal of Mechanics and Physics of Solids, 23.",
    author = "Manolis Veveakis and M Peters and T. Poulet and Ali Karrech and M Herwegh and Klaus Regenauer-Lieb",
    year = "2015",
    language = "English",
    note = "European Geosciences Union, General Assembly 2015 ; Conference date: 12-04-2015 Through 17-04-2015",
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    Veveakis, M, Peters, M, Poulet, T, Karrech, A, Herwegh, M & Regenauer-Lieb, K 2015, 'Material instabilities and their role for the initiation of boudinage and folding structures' European Geosciences Union, General Assembly 2015, Vienna, Austria, 12/04/15 - 17/04/15, .

    Material instabilities and their role for the initiation of boudinage and folding structures. / Veveakis, Manolis; Peters, M; Poulet, T.; Karrech, Ali; Herwegh, M; Regenauer-Lieb, Klaus.

    2015. Abstract from European Geosciences Union, General Assembly 2015, Vienna, Austria.

    Research output: Contribution to conferenceAbstract

    TY - CONF

    T1 - Material instabilities and their role for the initiation of boudinage and folding structures

    AU - Veveakis, Manolis

    AU - Peters, M

    AU - Poulet, T.

    AU - Karrech, Ali

    AU - Herwegh, M

    AU - Regenauer-Lieb, Klaus

    PY - 2015

    Y1 - 2015

    N2 - Localized phenomena, such as pinch-and-swell boudinage or localized folds, are usually interpreted to arise from viscosity contrasts. These are caused by structural heterogeneities, such as geometric or material imperfections. An alternative possibility for strain localization exists in material science, where dynamic localization emerges out of a steady state for a given critical set of material parameters and loading rates (Montési and Zuber, 2002). In our contribution, we will investigate the conditions under which this type of instabilities triggers localized deformation. Moreover, we discuss whether geological materials necessarily require structural heterogeneities, such as weak seeds, in order to generate aforementioned localized structures. We set up a random distribution of grain sizes in a layer embedded in a matrix with a diffusion creep rheology. Deformation within the layer is accommodated by dislocation and diffusion creep as end member deformation mechanism. The grain size evolution follows the paleowattmeter scaling relationship for calcite creep (Austin and Evans, 2007), which is controlled by thermo-mechanical feedbacks (Herwegh et al., 2014). During the first strain increments in the numerical simulation, the layer establishes a viscous steady state, which is the systems' response to optimize energy following the paleowattmeter (Herwegh et al., 2014). With further loading, localization interestingly arises out of a homogeneous state. We will demonstrate the robustness of this numerical solution by identifying the natural mode shapes and frequencies of the simulated structure and material parameters, including geometric imperfections (Rudnicki and Rice, 1975). This technique aims at the determination of the spatial manifestation of the instability pattern (Peters et al., in review). The eigenvalues are thought to represent the nodal points, where the onset of (visco)-elasto-plastic localization can initiate in the structure (Rudnicki and Rice, 1975). The eigenmodes appear as sinusoidal vibrations with geometry- and material parameter-specific natural modal frequencies and shapes. In a next step, the eigenmodes are perturbed and superposed to the initial conditions. We observe that this pattern of perturbations guides the ultimate material bifurcation. Boudinage and folding can therefore be seen as either a pure geometric problem or a fundamental material bifurcation, which evolves out of homogeneous state. The latter class offers the great possibility to extract fundamental material parameters out of localized structures directly from field observations. REFERENCES Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research, 119. Montési, L.G.J. and Zuber, M.T. (2002). A unified description of localization for application to large-scale tectonics. Journal of Geophysical Research, 107. Peters, M., Veveakis, M., Poulet, T., Karrech, A., Herwegh, M. and Regenauer-Lieb Klaus (in review). Boudinage as a material instability of elasto-visco-plastic rocks. Submitted to Journal of Structural Geology. Rudnicki, J. W., Rice, J. R. (1975). Conditions for the localization of deformation in pressure-sensitive dilatant materials. Journal of Mechanics and Physics of Solids, 23.

    AB - Localized phenomena, such as pinch-and-swell boudinage or localized folds, are usually interpreted to arise from viscosity contrasts. These are caused by structural heterogeneities, such as geometric or material imperfections. An alternative possibility for strain localization exists in material science, where dynamic localization emerges out of a steady state for a given critical set of material parameters and loading rates (Montési and Zuber, 2002). In our contribution, we will investigate the conditions under which this type of instabilities triggers localized deformation. Moreover, we discuss whether geological materials necessarily require structural heterogeneities, such as weak seeds, in order to generate aforementioned localized structures. We set up a random distribution of grain sizes in a layer embedded in a matrix with a diffusion creep rheology. Deformation within the layer is accommodated by dislocation and diffusion creep as end member deformation mechanism. The grain size evolution follows the paleowattmeter scaling relationship for calcite creep (Austin and Evans, 2007), which is controlled by thermo-mechanical feedbacks (Herwegh et al., 2014). During the first strain increments in the numerical simulation, the layer establishes a viscous steady state, which is the systems' response to optimize energy following the paleowattmeter (Herwegh et al., 2014). With further loading, localization interestingly arises out of a homogeneous state. We will demonstrate the robustness of this numerical solution by identifying the natural mode shapes and frequencies of the simulated structure and material parameters, including geometric imperfections (Rudnicki and Rice, 1975). This technique aims at the determination of the spatial manifestation of the instability pattern (Peters et al., in review). The eigenvalues are thought to represent the nodal points, where the onset of (visco)-elasto-plastic localization can initiate in the structure (Rudnicki and Rice, 1975). The eigenmodes appear as sinusoidal vibrations with geometry- and material parameter-specific natural modal frequencies and shapes. In a next step, the eigenmodes are perturbed and superposed to the initial conditions. We observe that this pattern of perturbations guides the ultimate material bifurcation. Boudinage and folding can therefore be seen as either a pure geometric problem or a fundamental material bifurcation, which evolves out of homogeneous state. The latter class offers the great possibility to extract fundamental material parameters out of localized structures directly from field observations. REFERENCES Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research, 119. Montési, L.G.J. and Zuber, M.T. (2002). A unified description of localization for application to large-scale tectonics. Journal of Geophysical Research, 107. Peters, M., Veveakis, M., Poulet, T., Karrech, A., Herwegh, M. and Regenauer-Lieb Klaus (in review). Boudinage as a material instability of elasto-visco-plastic rocks. Submitted to Journal of Structural Geology. Rudnicki, J. W., Rice, J. R. (1975). Conditions for the localization of deformation in pressure-sensitive dilatant materials. Journal of Mechanics and Physics of Solids, 23.

    M3 - Abstract

    ER -

    Veveakis M, Peters M, Poulet T, Karrech A, Herwegh M, Regenauer-Lieb K. Material instabilities and their role for the initiation of boudinage and folding structures. 2015. Abstract from European Geosciences Union, General Assembly 2015, Vienna, Austria.