Showing papers in "Computational Materials Science in 1999"

TL;DR: In this paper, a multiscale behaviour model based on a multilevel finite element (FE2) approach is used to take into account heterogeneities in the behaviour between the fibre and matrix.

TL;DR: In this article, a numerical procedure for the computation of the overall moduli of polycrystalline materials based on a direct evaluation of a micro-macro transition is presented, where the deformation of the micro-structure is coupled with the local deformation at a typical point on the macrocontinuum by three alternative constraints of the microscopic fluctuation field.

TL;DR: In this article, a combination of numerical techniques was used to calculate the heat of solution, surface energies and segregation energies for a large number of metals and alloys, including Ni and Rh 75 Pt 25.

TL;DR: In this article, a simple mathematical model for calculating the chemical activity coefficients of ions in electrolytic solutions is presented to account for the particular behavior of concentrated solutions for which short-range and long-range interactions between ions are important.

TL;DR: In this paper, the authors consider surface segregation in alloys, i.e., concentration modulation in the surface selvedge at thermodynamical equilibrium, can be viewed as resulting from two kinds of competition or synergy.

TL;DR: Norm-conserving pseudopotential database (NCPS95) was prepared in 1995 and is distributed by CD-R media.

TL;DR: The multiple-scale RKPMs are proposed as an alternative to commonly used numerical methods such as the finite element method, suitable for problems with large deformations, high gradients, and localization problems.

TL;DR: In this article, the authors deal with the modelling of 1 − 3 and 0 − 3 composites made of piezoceramic fibres embedded in a soft non-piezoelectric matrix.

TL;DR: Positron lifetime calculations have been performed on vacancy clusters (stacking fault tetrahedra (SFT), vacancy loops), such clusters on dislocation line, interstitial clusters, such clusters in the dislocation lines and dislocations line itself in order to investigate the so-called intermediate lifetimes observed in the experiments, namely, positron lifetimes between that at a matrix and that at single vacancy as mentioned in this paper.

TL;DR: The determination of the smallest circle surrounding to the loading path that describes the tip of the shear stress vector acting on a material plane during one stress cycle is concerned.

TL;DR: In this article, a new embedded atom potential has been proposed, which is expressed by simple functions and is applicable to the molecular dynamics simulations of large atomic systems, and the potential parameters are determined from the experimental data using the cohesive energy, Born stability, elastic constants, C 11, C 12 and C 44, the formation energy of a vacancy.

TL;DR: In this paper, the Bozzolo, Ferrante and Smith (BFS) method is applied to several aspects of the computational modeling of surfaces and segregation, including alloy surface segregation, structure and composition of alloy surfaces, and the formation of surface alloys.

TL;DR: In this paper, one or more dislocations are simulated while gliding through obstacle fields of arbitrary type or spatial arrangement, where elastic self-interaction is fully allowed for.

TL;DR: In this article, the Gurson-Tvergaard-Needleman model is used to study crack propagation in a metal matrix composite (MMC) and the dominant failure mechanism observed is particle cracking.

TL;DR: In this article, the authors used the Grand Canonical Monte Carlo (GCMC) simulation to locate the interlayer cation and calculate the number of interlayer water molecules surrounding the cation for both the clay materials.

TL;DR: In this article, a molecular dynamics study has been performed on symmetrical tilt grain boundaries with the Σ 5 (3/1/0)/[0/0/1] θ =36.9° misorientation to investigate the structure and dynamics of interfaces in Yttria stabilized zirconia (YSZ).

TL;DR: In this article, a constitutive law for single crystal superalloys with a large volume fraction of the γ′ phase in the high temperature regime is proposed, which relies on a mechanical model of the dislocation mechanisms in the matrix and the particles.

TL;DR: In this article, the DV-Xα cluster method was used to understand alloying effects on the hydrogen absorption and desorption characteristics of a TiFe hydrogen storage compound, and it was found that hydrogen atoms make a strong chemical bond with Fe atoms rather than Ti atoms in pure TiFe, despite the larger affinity of Ti atoms for hydrogen than Fe atoms in the binary metal-hydrogen system.

TL;DR: In this article, a numerical model of deformation, damage and fracture in particle-reinforced composite materials, based on the method of multiphase finite elements (MPFE) and element elimination technique (EET), is presented.

TL;DR: In this paper, a detailed study of Shockley partials in Pd is presented, using a full-scale atomistic simulation of the structure and energetics of the dislocation motion.

TL;DR: In this article, first-principles molecular dynamics simulations were used to investigate the potential of atomic removal through the solid phase chemical interaction between surfaces of ultra-fine powders and works.

TL;DR: In this article, the incorporation of higher order strain gradients into the constitutive equations of continuum damage mechanics is presented, and an elegant possibility of describing anisotropic material behavior based on the microplane theory is demonstrated.

TL;DR: In this paper, a generalized-gradient approximation (GGA) was used to calculate the lattice relaxation energy for a vacancy in Cu and Al. The calculations are based on density-functional theory and the full-potential Korringa-Kohn-Rostoker Green's function method for impurities.

TL;DR: In this paper, the authors used Monte Carlo (MC) methods, in conjunction with empirical embedded atom method and Finnis-Sinclair potentials, for modeling surface segregation phenomena in ternary alloys.

TL;DR: In this paper, a self-consistent matricity model was developed to simulate the mechanical behaviour of composites with two randomly distributed phases of interpenetrating microstructures.

TL;DR: In this article, the influence of the microstructure on the macro-, meso- and micro-effects in metal-matrix composites is investigated by direct combination of experiment and simulation.

TL;DR: In this article, computational and experimental results are presented concerning residual stress effects on fatigue crack growth in a Compact Tension Shear (CTS) specimen under cyclic mode I loading.

TL;DR: In this article, a mean field model is used to model the behavior of the aggregate of two-phase grains, using a model for multi-phase materials, and simulations are performed on a unit cubic cell representing the percolated networks.

TL;DR: In this paper, a hierarchical expansion of yield functions to hardening tensors of the fourth and the sixth order is proposed to cover the material behaviour with distorted yield surfaces, which correspond to affin expansions or simple shifting of original yield surfaces.

TL;DR: In this paper, a new phenomenological method has been developed for the prediction of the progress of non-isothermal diffusional transformation processes based on the traditional Scheil-Cahn additivity principle.