Now showing 1 - 3 of 3
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    Publication
    A discrete dislocation model of creep in single crystals
    (01-01-2016)
    Rajaguru, M.
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    We present a new computational approach for modeling dislocation creep in metals using kinetic Monte Carlo simulation of thermally activated dislocation glide, extending the discrete dislocation dynamics method of plasticity. The method is used to study the problem of power-law creep in precipitation strengthened Aluminum single crystals. The new model predicts creep rates and stress exponents consistent with their known ranges from experiments.
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    Publication
    Ductile fracture simulations using a multi-surface coupled damage-plasticity model
    (01-01-2017)
    Reddi, D.
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    In this paper, an isotropic porous metal plasticity model accounting for both void growth by diffuse plastic deformation and void 'coalescence' by localization of plastic flow in the inter-void ligaments is presented. Predictions for the effective stress-strain response, evolution of damage and the strains to failure are obtained by integrating the model numerically under triaxial proportional loading conditions. The model predictions are compared with results from micromechanical finite element simulations of the average response of voided unit cells under similar loading conditions. It is shown that the model predictions for the failure strains as a function of the loading path are in good qualitative agreement with the results of the cell model simulations.
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    Publication
    Analysis of ductile fracture using a micromechanics-based coupled damage-plasticity model
    (01-01-2017)
    The prediction of ductile fracture under low triaxiality shear dominated loadings is of significant technological interest. Here, we use an extension of the Gurson model that accounts for localized modes of plasticity at the micro-scale to predict the ductilities of macro-scale specimens under low triaxiality loading conditions. The model is integrated for various radial loading paths in stress space and predictions for ductility are obtained from the condition of the onset of plastic instability at the macro-scale. It is seen that the loading path dependence of the predicted ductility is consistent with recent experimental data from the literature.