• Mater. Theory Pub Date : 2020-05-24
Yongfeng Zhang; Yipeng Gao; Cheng Sun; Daniel Schwen; Chao Jiang; Jian Gan

One of the most intriguing phenomena under radiation is the self-organization of defects, such as the void superlattices, which have been observed in a list of bcc and fcc metals and alloys when the irradiation conditions fall into certain windows defined by temperature and dose rate. A superlattice features a lattice parameter and a crystal structure. Previously, it has been shown that the superlattice

更新日期：2020-05-24
• Mater. Theory Pub Date : 2020-04-17
Eric J Bylaska; Kevin Waters; Eric D Hermes; Judit Zádor; Kevin M Rosso

An efficient and accurate approach for calculating exact exchange and other two-electron integrals has been developed for periodic electronic structure methods. Traditional approaches used for integrating over the Brillouin zone in band structure calculations, e.g. trapezoidal or Monkhorst-Pack, are not accurate enough for two-electron integrals. This is because their integrands contain multiple singularities

更新日期：2020-04-17
• Mater. Theory Pub Date : 2020-04-16
Amit Acharya; Shankar C. Venkataramani

Growth and other dynamical processes in soft materials can create novel types of mesoscopic defects including discontinuities for the second and higher derivatives of the deformation, and terminating defects for these discontinuities. These higher-order defects move “easily", and can thus confer a great degree of flexibility to the material. We develop a general continuum mechanical framework from

更新日期：2020-04-16
• Mater. Theory Pub Date : 2020-04-07

A theoretical model for computing the interstitial solute concentration and the interstitial solute-induced stress field in a three-dimensional finite medium with any arbitrary elastic fields was developed. This model can be directly incorporated into two-dimensional or three-dimensional discrete dislocation dynamics simulations, continuum dislocation dynamics simulations, or crystal plasticity simulations

更新日期：2020-04-07
• Mater. Theory Pub Date : 2019-11-01
S. Papanikolaou; P. Shanthraj; J. Thibault; C. Woodward; F. Roters

Crack initiation emerges due to a combination of elasticity, plasticity, and disorder, and it displays strong dependence on the material’s microstructural details. The characterization of the structural uncertainty in the original microstructure is typically empirical and systematic characterization protocols are lacking. In this paper, we propose an investigational tool in the form of the curvature

更新日期：2019-11-01
• Mater. Theory Pub Date : 2019-05-27
Carolina Baruffi; Alphonse Finel; Yann Le Bouar; Brigitte Bacroix; Oguz Umut Salman

Macroscopic properties of structural materials are strongly dependent on their microstructure. However, the modeling of their evolution is a complex task because of the mechanisms involved such as plasticity, recrystallization, and phase transformations, which are common processes taking place in metallic alloys. This complexity led to a growing interest in atomistic simulations formulated without

更新日期：2019-05-27
• Mater. Theory Pub Date : 2019-03-15
Giacomo Po; Nikhil Chandra Admal; Markus Lazar

We derive the Green tensor of Mindlin’s anisotropic first strain gradient elasticity. The Green tensor is valid for arbitrary anisotropic materials, with up to 21 elastic constants and 171 gradient elastic constants in the general case of triclinic media. In contrast to its classical counterpart, the Green tensor is non-singular at the origin, and it converges to the classical tensor a few characteristic

更新日期：2019-03-15
• Mater. Theory Pub Date : 2019-01-31
Laurent Capolungo; Vincent Taupin

A mesoscale model is introduced to study the dynamics of material defects lying at interface junctions. The proposed framework couples the dynamics of discrete dislocation and disclination lines. Disclinations are expected to be natural defects at interface junctions; their presence serving the purpose of accommodating discontinuities in rotation fields at material interface junctions. Crystallography-based

更新日期：2019-01-31
• Mater. Theory Pub Date : 2019-01-25
M. H. Braga; N. S. Grundish; A. J. Murchison; J. B. Goodenough

An electrochemical cell contains three open thermodynamic systems that, in dynamic equilibrium, equalize their electrochemical potentials with that of their surrounding by forming an electric-double-layer-capacitor at the interface of the electrolyte with each of the two electrodes. Since the electrode/electrolyte interfaces are heterojunctions, the electrochemical potentials or Fermi levels of the

更新日期：2019-01-25
• Mater. Theory Pub Date : 2018-08-15
Hunter Swan; Woosong Choi; Stefanos Papanikolaou; Matthew Bierbaum; Yong S. Chen; James P. Sethna

We explore new ways of regulating defect behavior in systems of conservation laws. Contrary to usual regularization schemes (such as a vanishing viscosity limit), which attempt to control defects by making them smoother, our schemes result in defects which are more singular, and we thus refer to such schemes as “irregularizations”. In particular, we seek to produce delta shock defects which satisfy

更新日期：2018-08-15
• Mater. Theory Pub Date : 2018-05-23
Tohid Naseri; Daniel Larouche; Rémi Martinez; Francis Breton

An exact analytical solution of the Fick’s second law was developed and applied to the mixed-mode growth of a multicomponent ellipsoidal precipitate growing with constant eccentricities in the quasi-stationary regime. The solution is exact if the nominal composition, equilibrium concentrations and material properties are assumed constant, and can be applied to compounds having no limitations in the

更新日期：2018-05-23
• Mater. Theory Pub Date : 2018-03-20
Mehran Monavari; Michael Zaiser

Continuum dislocation dynamics (CDD) aims at representing the evolution of systems of curved and connected dislocation lines in terms of density-like field variables. Here we discuss how the processes of dislocation multiplication and annihilation can be described within such a framework. We show that both processes are associated with changes in the volume density of dislocation loops: dislocation

更新日期：2018-03-20
• Mater. Theory Pub Date : 2018-01-31
Stefan Liebenstein; Michael Zaiser

We present results of a two-scale model of disordered cellular materials where we describe the microstructure in an idealized manner using a beam network model and then make a transition to a Cosserat-type continuum model describing the same material on the macroscopic scale. In such scale transitions, normally either bottom-up homogenization approaches or top-down reverse modeling strategies are used

更新日期：2018-01-31
• Mater. Theory Pub Date : 2018-01-31
K. Ahmed; A. El-Azab

A formal asymptotic analysis of two classes of phase field models for void growth and coarsening in irradiated solids has been performed to assess their sharp-interface kinetics. It was found that the sharp interface limit of type B models, which include only point defect concentrations as order parameters governed by Cahn-Hilliard equations, captures diffusion-controlled kinetics. It was also found

更新日期：2018-01-31
• Mater. Theory Pub Date : 2017-07-28
Andrew A. Prudil; Michael J. Welland

Upon publication of the original manuscript (Prudil and Welland 2017) discrepancies were highlighted in Eq. (50) [equation (1) here]. The equation in the original manuscript (Prudil and Welland 2017) erroneously included a factor of 2 on theta and read:$$\cos \left(2\theta \right)=\frac{\sigma_{\alpha \gamma }}{2{\sigma}_{\alpha \beta }}$$(1) This equation should read as below: \cos \left(\theta

更新日期：2017-07-28
• Mater. Theory Pub Date : 2017-07-11
Nikhil Chandra Admal; Giacomo Po; Jaime Marian

The standard way of modeling plasticity in polycrystals is by using the crystal plasticity model for single crystals in each grain, and imposing suitable traction and slip boundary conditions across grain boundaries. In this fashion, the system is modeled as a collection of boundary-value problems with matching boundary conditions. In this paper, we develop a diffuse-interface crystal plasticity model

更新日期：2017-07-11
• Mater. Theory Pub Date : 2017-06-21
Christopher S. R. Matthes; Nasr M. Ghoniem; Daniel Walgraef

We present a continuum model of ion-induced surface patterning. The model incorporates the atomic processes of sputtering, re-deposition and surface diffusion, and is shown to display the generic features of the damped Kuramoto-Sivashinsky (KS) equation of non-linear dynamics. Linear and non-linear stability analyses of the evolution equation give estimates of the emerging pattern wavelength and spatial

更新日期：2017-06-21
• Mater. Theory Pub Date : 2017-05-25
Anter El-Azab

Materials science is an interdisciplinary field with the broad objectives of understanding the structure and properties of materials and the discovery of new materials. In his historical account of this field titled The Coming of Materials Science (Cahn et al. 2003), R. W. Cahn referred to the middle of the past century as the time materials science was born out of metallurgy. Materials science has

更新日期：2017-05-25
• Mater. Theory Pub Date : 2017-05-25
K. Y. Volokh

Cracks are created by massive breakage of molecular or atomic bonds. The latter, in its turn, leads to the highly localized loss of material, which is the reason why even closed cracks are visible by a naked eye. Thus, fracture can be interpreted as the local material sink. Mass conservation is violated locally in the area of material failure. We consider a theoretical formulation of the coupled mass

更新日期：2017-05-25
• Mater. Theory Pub Date : 2017-05-25
Andrew A. Prudil; Michael J. Welland

A new computationally efficient model of an included phase located at the interface between two other phases is developed by projecting the boundaries of the inclusion onto the boundary between the two other phases. This reduces the 3D problem to one on a 2D surface while still being embedded in 3D space, which significantly reduces computational expense of solving the system. The resulting model is

更新日期：2017-05-25
• Mater. Theory Pub Date : 2017-05-25
Markus Hütter; Bob Svendsen

The purpose of the current work is the formulation of models for conservative and non-conservative dynamics in solid systems with the help of the General Equation for the Non-Equilibrium Reversible-Irreversible Coupling (GENERIC: e.g., Grmela and Öttinger, Phys. Rev. E 56(6), 6620 (1997); Öttinger and Grmela, Phys. Rev. E 56(6), 6633 (1997)). In this context, the resulting models are inherently spatially

更新日期：2017-05-25
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