Showing papers in "Computational Materials Science in 2006"

TL;DR: In this article, an algorithm for decomposition of electronic charge density into atomic contributions is presented. But instead of explicitly finding and representing the dividing surfaces, which is a challenging task, the algorithm assigns each point on a regular (x,y,z) grid to one of the regions by following a steepest ascent path on the grid.

TL;DR: Based on the ABAQUS software, uncoupled thermal-mechanical three-dimensional and two-dimensional (2-D) finite element models are developed in this article to evaluate the transient temperature and the residual stress fields during welding.

TL;DR: In this paper, the results of first-principles theoretical study of the structural, electronic and optical properties of zinc monochacogenides ZnS, ZnSe and ZnTe, have been performed using the full-potential linear augmented plane-wave method plus local orbitals (FP-APW + lo) as implemented in the WIEN2k code.

TL;DR: In this paper, the Hartree-Fock (HF) method and the density functional theory (DFT) were used to calculate anisotropic elastic constants of titanium diboride, TiB 2.

TL;DR: In this article, a thermal elastic plastic finite element model taking into account the metallurgical phase transformation was developed to investigate the influence of solid-state phase transformation on the evolution of residual stress distributions in butt-welded modified 9Cr-1Mo steel pipes.

TL;DR: In this article, the acoustic properties of a stacked fiber non-woven are modeled by a macroscopically homogeneous random system of straight cylinders (tubes), and the flow is computed in digitized realizations of the stochastic geometric model using the lattice Boltzmann method.

TL;DR: In this paper, the authors compare stress and strain distributions between a periodic and a random model for a carbon reinforced polymer and show that periodic models may be used for simulation of effective properties but random models must be considered for the simulation of local phenomena such as local damage or matrix cracking.

TL;DR: In this article, the authors study the formulae of Murnaghan's equation of state, reported in the literature and used to fit the theoretical electronic ground state energy and obtain thermodynamical quantities like the bulk modulus.

TL;DR: In this paper, the effect of the tool geometry on the cutting process was investigated, and it was observed that with negative rake angle, the chip becomes smaller due to the larger plastic deformation generated in the workpiece.

TL;DR: In this article, the structural, electronic and optical properties of two chalcopyrite crystals: CuGaS 2 and AgAgS 2 are studied using the full potential linearized augmented plane waves method within the local density approximation (LDA) Geometrical optimization of the unit cell (equilibrium volume, c / a ratio, internal parameter u, and bulk modulus) is in good agreement with experimental data The energy gap is found to be direct for both materials and the nature of the gap crucially depends on the manner in which the Ga 3d and (Ag 4

TL;DR: In this paper, a theoretical study of structural, electronic, elastic and high pressure properties in barium chalcogenides BaX (X = S, Se, Te, Po) is performed, using the full-potential augmented plane wave plus local orbitals method.

TL;DR: In this article, the influence of fracture criterion in numerical simulations of the perforation process has been studied for three different steel alloys and the results showed that the ballistic limit can be quantitatively well predicted independent of the chosen fracture criterion.

TL;DR: In this paper, the authors considered the kinetics of isothermal primary recrystallization of metallic materials using a two-dimensional cellular automata model and compared the results with predictions of JMAK theory for 2D growth.

TL;DR: In this article, the authors compared Young's modulus of single-wall carbon nanotubes given by four common methods based on (i) the determination of stress for a fixed value of strain, (ii) strain energy, (iii) the longitudinal vibrations, and (iv) transverse vibrations.

TL;DR: In this paper, the authors presented the results of predicting thermodynamic analysis with the aim to determine the crucible oxide stability in contact with molten titanium and titanium-aluminum alloys.

TL;DR: In this article, the authors presented new results of ab initio total energy calculations of small iron clusters, Fen with 2 −n−n−⩽n−15, in which structural Jahn-Teller like distortion and competing non-collinear and collinear magnetic moments have been taken care of simultaneously.

TL;DR: In this article, the interface deformation between welding arc and weld pool is solved by updating the calculation region of arc and welding pool continually, and the weld pool shape calculated by dynamic coupling is more close to the experiment than that of non coupling calculation.

TL;DR: In this article, an experimental and numerical study of the induction heat treatment applied to ISO C45 steel was carried out, where both normalised and annealed samples were considered.

TL;DR: In this article, the ground state properties and structural phase transformation of beryllium chalcogenides (BeS, BeSe, and BeTe) have been investigated using first principle full potential-linearized augmented plane wave method (FP-LAPW) within density functional theory.

TL;DR: In this paper, a fully three-dimensional thermo-mechanically coupled FEMsimulation of the production of a connecting rod has been performed, where workpieces from all stages of the process are used to examine the geometry, microstructure and local mechanical properties.

TL;DR: In this article, the structural, electronic and elastic properties of beryllium chalcogenides BeS, BeSe and BeTe were investigated using the full-potential linear muffin-tin orbital (FP-LMTO) method.

TL;DR: In this paper, an analytical model to estimate the angle bent during the laser forming of a sheet is presented, which is based on a history-dependent incremental stress-strain relationship.

TL;DR: In this article, a cohesive interface element for ductile tearing of thin structures modelled by plane-stress continuum or shell elements is presented which accounts for thickness reduction, which prevents localisation of plastic deformation in the adjacent continuum elements often inhibiting crack extension and leading to divergence of the numerical simulations.

TL;DR: In this paper, a polycrystal plasticity model of the cyclic behavior of the titanium alloy Ti6Al4V is presented and used in a finite element model of fretting.

TL;DR: In this article, the three materials AA7108, AA7003 and AA6060, which can be parts of a typical bumper system in aluminum, were characterized through simple material tests including through-thickness compression tests, and quasi-static and dynamic tensile tests, material properties were identified for two material models that have recently been implemented in LS-DYNA.

TL;DR: In this paper, a numerical model is developed to simulate the critical droplet break-up during high pressure gas atomization, and the model is integrated with the flow field generated high-pressure gas nozzle to provide quantitative assessment for atomisation process.

TL;DR: In this article, a finite element model of a unit cell is proposed for predicting the thermal properties of ceramic matrix composites through finite element modeling of a representative unit cell, where thermal transport behavior is modelled using a commercial FE code to conduct steady state and transient analyses on the unit cell.

TL;DR: In this article, first principles calculations have been used to investigate the elastic and the bonding properties of barium chalcogenides BaS, BaSe, and BaTe at equilibrium as well as high pressures using full potential-linearized augmented plane wave (FP-LAPW) method within density functional theory.

TL;DR: In this paper, the atomic structures of small zinc oxide clusters (ZnO)n n−⩽-6 using ultrasoft pseudopotential method and the generalized gradient approximation for the exchange-correlation energy.

TL;DR: In this paper, a new procedure for the sampling of crystallographic textures into discrete lattice orientations is presented, for example, useful in order to assign initial grain orientations in crystal-plasticity-based finite element simulation of forming processes.