Showing papers in "Computational Materials Science in 2008"

TL;DR: In this paper, the compressive deformation behavior of 42CrMo steel was investigated at the temperatures from 850 to 1150 ǫ c and strain rates from 0.01 to 50 s−1 on Gleeble-1500 thermo-simulation machine.

TL;DR: The projector augmented wave method (PAW) was implemented in the ABINIT code as discussed by the authors, which allows self-consistent calculations of the electronic structure of a periodic solid within the density functional theory (DFT), including the analytic calculation of forces and stresses.

TL;DR: Training and testing results have shown that artificial neural networks and fuzzy logic systems have strong potential for predicting 7, 28 and 90 days compressive strength of concretes containing fly ash.

TL;DR: In this paper, a three-dimensional, thermo-elastic-plastic, large deformation finite element method (FEM) is used to simulate welding distortion in a low carbon steel butt-welded joint with 1mm thickness.

TL;DR: In this article, the structural and elastic properties of NiAl under high pressures using norm-conserving pseudopotentials within the generalized gradient approximation correction (GGA) in the frame of density functional theory were investigated.

TL;DR: In this paper, a theoretical analysis to the FGM (functionally graded materials) thin plates based on the physical neutral surface is presented, which has more merits in the engineering application, because it is easier and simpler than classical laminated plate theory based on geometric middle surface.

TL;DR: In this paper, an artificial neural network (ANN) model is developed to predict the constitutive flow behaviors of 42CrMo steel during hot deformation, where the inputs of the neural network are deformation temperature, log strain rate and strain whereas flow stress is the output.

TL;DR: In this paper, a hybrid algorithm was proposed to improve the performance of the gradient-based algorithm, which is strongly dependent on the initial set of results, in order to analyse the effectiveness of this optimization procedure, numerical and experimental results for an EN AW-5754 aluminium alloy are compared.

TL;DR: The models in artificial neural networks and fuzzy logic systems for predicting compressive and splitting tensile strengths of recycled aggregate concretes containing silica fume have been developed at the age of 3, 7, 14, 28, 56 and 90 days.

TL;DR: In this article, both the experiment and the finite element method (FEM) are utilized to investigate the welding residual stress distribution in medium thick-walled austenitic stainless steel pipe.

TL;DR: In this paper, the authors considered the incorporation of Bi 5d states in photocatalysts and found that the transition positions of the transverse bands of the photocatalyst were almost independent of the incorporation and the incorporation, and the conduction-band bottom flattens with the increase in X atomic number.

TL;DR: In this paper, a model using damage mechanics on the mesoscale and usable for structural analysis can be built as a homogenized version of this reference model through previously developed bridges.

TL;DR: In this article, a mixed material model, which contains a size dependent term and a size independent term, is proposed to analyze the influence of material size effects and establish a martial model in micro/meso-scale.

TL;DR: In this paper, a finite element formulation for the computation of Young's and Shear modulus of single walled carbon nanotubes (SWCNTs) is presented.

TL;DR: In this paper, the authors used pseudopotential calculations to investigate the bonding nature, elastic property and hardness for ZrB 2 and HfB 2 for polycrystalline aggregate compared with extrapolated experimental data.

TL;DR: In this paper, high-order flexural theories for short functionally graded symmetric beams under three-point bending are presented, where the material properties of the plate are assumed to be graded continuously in the direction of thickness.

TL;DR: This k-points-multiband-FFT parallelization scheme based on an efficient multiband eigenvalue solver, called the locally optimal block preconditioned conjugate gradient method, and using an optimized three-dimensional (3D) fast Fourier transform (FFT) in the ab initio plane-wave code abinit is implemented.

TL;DR: In this article, a modified random sequential adsorption algorithm was employed to generate the complex geometry of a random fiber composite and the effect of the interaction between two over-crossing fibers on the overall elastic properties of the composite was evaluated using the finite element method for continuum micro-mechanical analysis.

TL;DR: In this paper, a prediction method of welding distortion, which combines thermo-elastic-plastic finite element method (FEM) and large deformation elastic FEM based on inherent strain theory and interface element method, was developed.

TL;DR: In this article, an elastic analysis for a thick cylinder made of functionally graded materials (FGMs) is carried out, where the property of FGMs is assumed to be exponential function form.

TL;DR: In this paper, the static recrystallization behaviors of 42CrMo steel were investigated by isothermal interrupted hot compression tests on Gleeble-1500 thermo-simulation machine.

TL;DR: In this article, the analysis of uniaxial deformation of nickel nanowires using molecular dynamics simulations, and address the strain rate effects on mechanical responses and deformation behavior.

TL;DR: In this article, the axial and torsional vibrations of single-walled carbon nanotubes (SWCNTs) of different helicities having aspect ratio (length/diameter) of about 15 have been studied using the MM3 potential.

TL;DR: In this paper, an artificial neural network (ANN) was used to estimate the compressive strength of steel fiber added lightweight concrete. And the test results obtained from the ANN are compared with the multi linear regression technique based on mean square error, mean absolute error, and correlation coefficient criteria.

TL;DR: In this paper, a reevaluation of the vibrational frequencies of carbon nanotubes conveying fluid was performed, with some new and fresh results as to how the vibration frequencies do vary with various values of flow velocity, indicating that coupled-mode flutter may occur at higher flow velocity.

TL;DR: In this paper, a new model of flow stress characterizing dynamic recrystallization (DRX) for magnesium alloy was put forward based on the Gleeble-1500 thermomechanical simulation tests of magnesium alloy AZ31B.

TL;DR: A set of routines that modify and improve the quality of a 2D mesh and construct a close-to-automatic mesh generator that requires only a few inputs, such as the linear sizes of the largest and smallest features in the micrograph.

TL;DR: In this paper, a cellular automaton was used to simulate dynamic recrystallization (DRX) during thermomechanical deformation, which can predict the final microstructure and flow curve to a high degree of accuracy.

TL;DR: In this paper, a mesoscopic cellular automaton (CA) model was developed to predict the microstructural evolution of the austenite recrystallization during multi-pass hot rolling of steel strip.

TL;DR: In this article, atomic simulations are used to investigate how grain boundary structure influences dislocation nucleation under uniaxial tension and compression for a specific class of symmetric tilt grain boundaries that contain the E structural unit.