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Abstract Dynamic shearing banding and fracturing in unsaturated porous media are significant problems in engineering and science. This article proposes a multiphase micro‐periporomechanics (PPM) paradigm for modeling dynamic shear banding and fracturing in unsaturated porous media. Periporomechanics (PPM) is a nonlocal reformulation of classical poromechanics to model continuous and discontinuous deformation/fracture and fluid flow in porous media through a single framework. In PPM, a multiphase porous material is postulated as a collection of a finite number of mixed material points. The length scale in PPM that dictates the nonlocal interaction between material points is a mathematical object that lacks a direct physical meaning. As a novelty, in the coupled PPM, a microstructure‐based material length scale is incorporated by considering micro‐rotations of the solid skeleton following the Cosserat continuum theory for solids. As a new contribution, we reformulate the second‐order work for detecting material instability and the energy‐based crack criterion and J‐integral for modeling fracturing in the PPM paradigm. The stabilized Cosserat PPM correspondence principle that mitigates the multiphase zero‐energy mode instability is augmented to include unsaturated fluid flow. We have numerically implemented the novel PPM paradigm through a dual‐way fractional‐step algorithm in time and a hybrid Lagrangian–Eulerian meshfree method in space. Numerical examples are presented to demonstrate the robustness and efficacy of the proposed PPM paradigm for modeling shear banding and fracturing in unsaturated porous media.
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This content will become publicly available on December 29, 2025
Computational Large‐Deformation‐Plasticity Periporomechanics for Localization and Instability in Deformable Porous Media
ABSTRACT In this article, we formulate a computational large‐deformation‐plasticity (LDP) periporomechanics (PPM) paradigm through a multiplicative decomposition of the deformation gradient following the notion of an intermediate stress‐free configuration. PPM is a nonlocal meshless formulation of poromechanics for deformable porous media through integral equations in which a porous material is represented by mixed material points with nonlocal poromechanical interactions. Advanced constitutive models can be readily integrated within the PPM framework. In this paper, we implement a linearly elastoplastic model with Drucker–Prager yield and post‐peak strain softening (loss of cohesion). This is accomplished using the multiplicative decomposition of the nonlocal deformation gradient and the return mapping algorithm for LDP. The paper presents a series of numerical examples that illustrate the capabilities of PPM to simulate the development of shear bands, large plastic deformations, and progressive slope failure mechanisms. We also demonstrate that the PPM results are robust and stable to the material point density (grid spacing). We illustrate the complex retrogressive failure observed in sensitive St. Monique clay that was triggered by toe erosion. The PPM analysis captures the distribution of horst and graben structures that were observed in the failed clay mass.
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- Award ID(s):
- 1944009
- PAR ID:
- 10563213
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- International Journal for Numerical and Analytical Methods in Geomechanics
- Volume:
- 49
- Issue:
- 4
- ISSN:
- 0363-9061
- Format(s):
- Medium: X Size: p. 1278-1298
- Size(s):
- p. 1278-1298
- Sponsoring Org:
- National Science Foundation
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