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

  • Singular crack-tip plastic fields in Tresca and Mohr–Coulomb solids
    International Journal of Solids and Structures, 2018
    Co-Authors: Panos Papanastasiou, David Durban
    Abstract:

    Abstract This paper investigates the singular plastic fields at crack tips for Tresca and Mohr–Coulomb Materials with power law hardening response. The singular values and the corresponding fields were determined over a range of Material parameters. For Tresca and Mohr–Coulomb associative Materials we verified that the dominant singularity is given by the HRR value. For non-associative Mohr–Coulomb Materials we found consistent deviations from the HRR value which increase with the degree of non-associativity. The near-tip stress, strain, displacement and plastic zone profiles are illustrated for few representative cases. For the Tresca solid we found that the singular displacement and strain fields decrease with increasing hardening exponent before becoming undetermined at the limit of the perfect plasticity. For a Mohr–Coulomb Material, with moderate pressure sensitive behavior, the strain and displacement fields are restored to values obtained for strong hardening behavior.

  • Spherical Cavity Expansion in a Drucker-Prager Solid
    Journal of Applied Mechanics, 1997
    Co-Authors: David Durban, Norman A. Fleck
    Abstract:

    A finite strain analysis is presented for the pressurized spherical cavity embedded in a Drucker-Prager medium. Material behavior is modeled by a nonassociated deformation theory which accounts for arbitrary strain-hardening. The governing equations of spherically symmetric response are reduced to a single differential equation with the effective stress as the independent variable. Some related topics are discussed including the elastic-perfectly plastic solid, the thin-walled shell, and the Mohr-Coulomb Material. Spontaneous growth (cavitation limit) of an internally pressurized cavity is treated as a self-similar process and a few numerical examples are presented. These illustrate, for different hardening characteristics, the pressure sensitivity of Material response and that deviations from normality always reduce the caviation pressure.

Panos Papanastasiou - One of the best experts on this subject based on the ideXlab platform.

  • Singular crack-tip plastic fields in Tresca and Mohr–Coulomb solids
    International Journal of Solids and Structures, 2018
    Co-Authors: Panos Papanastasiou, David Durban
    Abstract:

    Abstract This paper investigates the singular plastic fields at crack tips for Tresca and Mohr–Coulomb Materials with power law hardening response. The singular values and the corresponding fields were determined over a range of Material parameters. For Tresca and Mohr–Coulomb associative Materials we verified that the dominant singularity is given by the HRR value. For non-associative Mohr–Coulomb Materials we found consistent deviations from the HRR value which increase with the degree of non-associativity. The near-tip stress, strain, displacement and plastic zone profiles are illustrated for few representative cases. For the Tresca solid we found that the singular displacement and strain fields decrease with increasing hardening exponent before becoming undetermined at the limit of the perfect plasticity. For a Mohr–Coulomb Material, with moderate pressure sensitive behavior, the strain and displacement fields are restored to values obtained for strong hardening behavior.

  • singular crack tip plastic fields in tresca and mohr coulomb solids
    International Journal of Solids and Structures, 2017
    Co-Authors: Panos Papanastasiou, David Durba
    Abstract:

    Abstract This paper investigates the singular plastic fields at crack tips for Tresca and Mohr–Coulomb Materials with power law hardening response. The singular values and the corresponding fields were determined over a range of Material parameters. For Tresca and Mohr–Coulomb associative Materials we verified that the dominant singularity is given by the HRR value. For non-associative Mohr–Coulomb Materials we found consistent deviations from the HRR value which increase with the degree of non-associativity. The near-tip stress, strain, displacement and plastic zone profiles are illustrated for few representative cases. For the Tresca solid we found that the singular displacement and strain fields decrease with increasing hardening exponent before becoming undetermined at the limit of the perfect plasticity. For a Mohr–Coulomb Material, with moderate pressure sensitive behavior, the strain and displacement fields are restored to values obtained for strong hardening behavior.

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

  • singular crack tip plastic fields in tresca and mohr coulomb solids
    International Journal of Solids and Structures, 2017
    Co-Authors: Panos Papanastasiou, David Durba
    Abstract:

    Abstract This paper investigates the singular plastic fields at crack tips for Tresca and Mohr–Coulomb Materials with power law hardening response. The singular values and the corresponding fields were determined over a range of Material parameters. For Tresca and Mohr–Coulomb associative Materials we verified that the dominant singularity is given by the HRR value. For non-associative Mohr–Coulomb Materials we found consistent deviations from the HRR value which increase with the degree of non-associativity. The near-tip stress, strain, displacement and plastic zone profiles are illustrated for few representative cases. For the Tresca solid we found that the singular displacement and strain fields decrease with increasing hardening exponent before becoming undetermined at the limit of the perfect plasticity. For a Mohr–Coulomb Material, with moderate pressure sensitive behavior, the strain and displacement fields are restored to values obtained for strong hardening behavior.

Stephan Bless - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of penetration resistance of brittle Materials using spherical cavity expansion analysis
    Mechanics of Materials, 1996
    Co-Authors: Sikhanda Satapathy, Stephan Bless
    Abstract:

    Abstract In this paper, we show that the ‘target resistance’ of brittle Materials can be calculated accurately using spherical cavity expansion analysis and a conventional brittle Material model. The stress field ahead of the tip of the penetrator is assumed to have spherical symmetry. The brittle Material is modeled as an elastic Material which cracks under tension. The cracked Material is considered to be pulverized when it fails in compression, which is then characterized as a Mohr-Coulomb Material with pressure dependent shear strength. The target resistance value found from this analysis compares well with the reported experimental values for AD995 alumina (Al 2 O 3 ) and aluminum nitride (A1N).

  • Cavity Expansion Analysis of Brittle Materials.
    1995
    Co-Authors: Sikhanda Satapathy, Stephan Bless
    Abstract:

    Abstract : In this report, we show that the target resistance of brittle Materials can be calculated accurately using spherical cavity expansion analysis and a conventional brittle Material model. The stress field ahead of the tip of the penetrator is assumed to have spherical symmetry. The brittle Material is modeled as an elastic Material which cracks under tension. The cracked Material is considered to be pulverized when it fails in compression, which is then characterized as a Mohr-Coulomb Material with pressure dependent shear strength. The target resistance value found from this analysis compares well with the reported experimental values for AD995 alumina (Al2O3).

Ammar Dakhil - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic modelling of bridge approach slabs under moving loads
    Journal of King Saud University - Engineering Sciences, 2021
    Co-Authors: Ihsan Al-abboodi, Osamah Al-salih, Ammar Dakhil
    Abstract:

    Abstract Differential settlement is a common problem in the bridge-roadway transition zone. Approach slabs are often constructed to mitigate the uneven settlement in this problematic zone. An appropriate simulation of the dynamic response of moving loads, approach slab and soil Materials is necessary for realistic results. In the present study, the performance of the slab under traffic flow is investigated by a 3D dynamic analysis. For this purpose, the slab is modelled as a plate element while Mohr-Coulomb Material model is adopted for base, subbase and subgrade soils. A number of parameters were considered to study the sensitivity of the proposed model to some soil, slab and moving load parameters that contribute to the behaviour of the approach slab. The main variables investigated in this study were the slab thickness, the restriction condition of the slab, the subgrade stiffness, weight of the passing vehicles and the analysis method adopted in such problems. Analysis results including predicted deformations and slab bending moments provide engineers with the necessary engineering knowledge to understand the response of approach slabs under different conditions.