Results 211 to 220 of about 286,034 (261)

On scale invariance in anisotropic plasticity, gradient plasticity and gradient elasticity

International Journal of Engineering Science, 2009
A simple but robust scale invariance argument earlier used to derive flow rules for macroscopic kinematic hardening plasticity from the configuration of single slip is now applied to consider yielding of fiber reinforced composites as first pioneered, on a purely phenomenological basis, by Tony Spencer and his co-workers.
Elias C. Aifantis, Elias C. Aifantis
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Strain gradient plasticity in gradient structured metals

Journal of the Mechanics and Physics of Solids, 2020
Abstract Structural gradients in metallic materials can give rise to substantial extra strengths compared to their non-gradient counterparts. This strengthening effect originates from the plastic strain gradients arising in plastically deformed gradient structures.
Ting Zhu, Lei Lu, Zhao Cheng, Yin Zhang
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Gradient plasticity in isotropic solids [PDF]

Mathematics and Mechanics of Solids, 2021
We discuss a framework for the description of gradient plasticity in isotropic solids based on the Riemannian curvature derived from a metric induced by plastic deformation. This culminates in a flow rule in the form of a fourth-order partial differential equation for the plastic strain rate, in contrast to the second-order flow rules that have been ...
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On standard gradient plasticity and visco-plasticity

International Journal of Solids and Structures, 2021
Abstract This paper is devoted to the standard theory of gradient plasticity and visco-plasticity, cf. Gudmundson (2004), Fleck and Willis (2009) and the quoted references. Within the framework of the generalized standard materials and the generalized principle of virtual work, our attention is focussed on the mathematical basis of the theory in ...
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Strain gradients in plasticity [PDF]

Acta Mechanica, 1977
An analytical model of a plastically deforming solid is assumed to be a material where the second spatial gradients of strain are included in the constitutive equations. These constitutive equations are combined, in a one dimensional shearing problem, with the second law of thermodynamics and condition of thermodynamic stability. The results are that a
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Stability of strain-gradient plastic materials

Journal of the Mechanics and Physics of Solids, 2011
Abstract A formulation of Fleck and Willis (2009a,b) for strain-gradient plasticity has been adapted to provide possible descriptions for materials that initially strain-harden but eventually soften. In the absence of gradient terms, such material is unstable for any wavelength and subject to localization in the softening regime.
Dal Corso, Francesco, J. R. Willis
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On boundary conditions and plastic strain-gradient discontinuity in lower-order gradient plasticity

Journal of the Mechanics and Physics of Solids, 2004
Through linearized analysis and computation, we show that lower-order gradient plasticity is compatible with boundary conditions, thus expanding its predictive capability. A physically motivated gradient modification of the conventional Voce hardening law is shown to lead to a convective stabilizing effect in 1-D, rate-independent plasticity.
Sunil Saigal, H. Tang, John L. Bassani, Amit Acharya   +3 more
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Formulations of Strain Gradient Plasticity

2011
In the literature, different proposals for a strain gradient plasticity theory exist. So there is still a debate on the formulation of strain gradient plasticity models used for predicting size effects in the plastic deformation of materials. Three such formulations from the literature are discussed in this work.
Forest, Samuel, Bertram, A.
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Fractional strain-gradient plasticity

European Journal of Mechanics - A/Solids, 2019
We develop a strain-gradient plasticity theory based on fractional derivatives of plastic strain and assess its ability to reproduce the scaling laws and size effects uncovered by the recent experiments of Mu et al. (2014, 2016, 2017) on copper thin layers undergoing plastically constrained simple shear.
C.F.O. Dahlberg, M. Ortiz
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