Reloading in Barodesy

Objectives

  • Development of Barodesy
  • Incoorporation of the intergranular strain concept
  • Improved reloading extension
  • Numerical implementation and application of Barodesy

Team

The Project is funded by the research grant of the Austrian Science Fund (FWF) P 28934-N32 : Reloading in Barodesy

fwf_logo_var2

ASBS

Project Description

Constitutive models are physical theories which link stresses with the resulting deformation and thus should enable a realistic simulation of material behavior. Constitutive modelling is a core subject in geotechnical engineering, as the quality of every numerical simulation depends on the used model. Barodesy, a constitutive model for soil, shows similarities to hypoplasticity and differs from the mainstream approach of elasto-plasticity. It is characterized by its mathematical simplicity and captures many important aspects of soil behavior.

The question ‘what information can be stored in soil?’ can be expressed as follows in mathematical terms: ‘what are the independent variables in a constitutive model?’ In the present form of barodesy, the memory of soil is stored only in two state variables, stress and void ratio. It is astonishing to note how many effects can be described with such a ‘poor’ memory. However, in some cases it is not possible to distinguish between monotonic loading and reloading and consequently it is not possible to describe cyclic loading paths. The aim of this proposal is to extend barodesy to capture reloading. In soil mechanics it is known that changing the direction of loading will lead to a temporary increase of stiffness compared to monotonic loading. The direction of deformation is described by the so-called stretching tensor. Thus, a change of stretching should yield a temporary increase of stiffness.

The underlying hypothesis is that constitutive models, and in this case barodesy, can be designed on the basis of so-called tensorial relations. It is expected to establish a relation that will provide a new and simple way to model (in terms of mathematics) irreversible mechanical behavior. The already introduced barodesy is a convincing new paradigm, and this proposal aims at closing a gap in this respect. The extended barodetic equation will be compared with experimental data as well as with other constitutive models. It is expected to achieve scientific progress in the field of constitutive modelling.  

 

Reloading in an oedometric compression test using the intergranular strain concept
Simulation of an oedometric compression test using barodesy with the intergranular strain concept (IS).

 Publications

Journal articles (peer-reviewd)
  • Bode, Manuel; Fellin, Wolfgang; Mašín, David; Medicus, Gertraud; Ostermann, Alexander (2020): An intergranular strain concept for material models formulated as rate equations.
    In: International Journal for Numerical and Analytical Methods in Geomechanics, S. 1 - 16. (DOI) (Weblink)

  • Medicus, Gertraud (2020): Asymptotic state boundaries and peak states in barodesy for clay.
    In: Géotechnique Letters Vol 10/2, pp. 1 - 8. (DOI)

  • Bode, M.; Schranz, F.; Medicus, G.; Fellin, W. (2019): Vergleich unterschiedlicher Materialmodelle an einer Aushubsimulation. In: geotechnik. Organ der Deutschen Gesellschaft für Geotechnik 42/1, S. 11 - 20. (DOI) (Weblink)
  • Medicus, Gertraud; Schneider-Muntau, Barbara (2019): Simulations of Fine-Meshed Biaxial Tests with Barodesy. In: Geosciences 9/1, No. 20. (DOI) (Web link)

  • Medicus, Gertraud; Schneider-Muntau, Barbara; Kolymbas, Dimitrios (2019): Second-order work in barodesy.
    In: Acta Geotechnica 14, pp. 1483 - 1493. (DOI) (Web link)

  • Medicus, G.; Fellin, W.; Schranz, F. (2018): Konzepte der Barodesie.
    In: Bautechnik 95/9, pp. 620 - 638. (URN) (DOI) (Web link)

  • Schneider-Muntau, Barbara; Medicus, Gertraud; Fellin, Wolfgang (2018): Strength reduction method in Barodesy. In: Computers and Geotechnics 95, pp. 57 - 67. (DOI) (Web link)
Journal Article (Proceedings Paper)
  • Tschuchnigg, Franz; Medicus, Gertraud; Schneider-Muntau, Barbara (2019): Slope stability analysis: Barodesy vs linear elastic - perfectly plastic models.
    In: E3S Web of Conferences 92/16014. (DOI)
Proceedings (Full Paper)
  • Medicus, Gertraud; Fellin, Wolfgang; Kolymbas, Dimitrios; Schranz, Fabian (2019): Concepts of Barodesy.
    In: Wu, Wei: Desiderata Geotechnica. China Europe Conference on Geotechnical Engineering, 13.-16. August 2018. Cham: Springer International Publishing (= Springer Series in Geomechanics and Geoengineering)., ISBN 978-3-030-14987-1, pp. 99 - 112. (DOI) (Web link)
Proceedings Article (Abstract) 
  • Bode, M.; Fellin, W.; Mašín, D.; Medicus, G.; Ostermann, A. (2019): Application of the intergranular strain concept to barodesy.
    In: Benahmed, Nadia; Wautier, Antoine: 30th ALERT Workshop Poster Session. Poster Session. Grenoble: Grenoble Institute of Technology (INP)., ISBN 978-2-9561359-5-1, pp. 16 - 17. (Web link)

  • Medicus, Gertraud; Schneider-Muntau, Barbara; Desrues, Jacques; Andò, Edward; Viggiani, Cino (2019): Peak strength influenced by scattering density - Simulations with hypoplasticity.
    In: Benahmed, Nadia; Wautier, Antoine: 30th ALERT Workshop Poster Session. Poster Session. Grenoble: Grenoble Institute of Technology (INP)., ISBN 978-2-9561359-5-1, pp. 14 - 15. (Web link)

  • Medicus, G.; Schneider-Muntau, B. (2018): Stress-dilatancy in barodesy.
    In: Pietruszczak, Stan; Pande, Gyan; Tamagnini, Claudio: 4 th International Symposium on Computational Geomechanics (ComGeo IV). Book of Extended Abstracts. 2-4 May 2018, Palazzo Bernabei, Assisi, Italy,. Rhodes: International Centre for Computational Engineering (IC2E)., ISBN 978-960-98750-3-5, pp. 22 - 23. (Web link)
Poster Presentation
  • Lecturer(s): Bode, M. Co-author(s): Fellin, W; Mašín, D.; Medicus, G.; Ostermann, A.: Application of the intergranular strain concept to barodesy.
    30th ALERT Workshop and School, Aussois, 2019-09-30. (Link to poster, Web link)

  • Lecturer(s): Medicus, Gertraud Co-author(s): Schneider-Muntau, Barbara; Desrues, Jacques; Andò, Edward; Viggiani, Cino: Peak strength influenced by scattering density - Simulations with hypoplasticity.
    30th ALERT Workshop and School, Aussois, 2019-09-30. (Link to poster, Web link)

  • Lecturer(s): Medicus, Gertraud Co-author(s): Schneider-Muntau, Barbara; Fellin, Wolfgang: Applications of barodesy.
    28th ALERT Workshop, Aussois, 2017-10-02.

Utilities and Links

              (Implementation of Intergranular Strain extension will follow soon)

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