A general model of solids with vectorial microstructures is introduced. The field equationsare the obtained as Euler-Lagrange equations of a suitable energetic functional. The Cosserat model is encompassed in this model and it can be used to study the behaviour of granular media. A first approach to this problem deals with a two dimensional model, since in such a case the field equations have a...

A model is presented for the dynamic finite element analysis of ceramic microstructures subjected to multi-axial dynamic loading. This model solves an initial-boundary value problem using a multi-body contact scheme integrated with interface elements to simulate microcracking at grain boundaries and subsequent large sliding, opening and closing of interfaces. A systematic and parametric study o...

A light scattering model under the Rayleigh-Gans-Debye approximation has been developed for polycristalline alumina. The model states that transmittance of dense alumina ceramics basically depends not only on the maximum grain size but also on the preferential orientation of their c-axis, or texture. The effect of texture in transparency has been experimentally measured on several dense alumina...

We present an analysis, based upon atomistic simulation data, of the effect of Fe impurities on grain boundary migration in Al. The first step is the development of a new interatomic potential for Fe in Al. This potential provides an accurate description of Al–Fe liquid diffraction data and the bulk diffusivity of Fe in Al. We use this potential to determine the physical parameters in the Cahn–...

This study investigates the thermal conductivity Κ of polycrystalline niobium. We recall that superconducting cavities for particle accelerators are made of niobium. And, the thermal conductivity Κ is one of the factors which play an important role in the cooling of these cavities by the surrounding superfluid helium bath. Our experiments revealed a rather unexpected discrepancy in the thermal ...

The five parameter grain boundary character distribution quantifies the relative areas of different types of grain boundaries, distinguished by their lattice misorientation and grain boundary plane orientation. The viewpoint presented in this paper is that this distribution is a sensitive metric of polycrystalline structure that can be related to macroscopic properties. To demonstrate the influ...

This paper describes a GA for job shop scheduling problems. Using the Giffler and Thompson algorithm, we created two new operators, THX crossover and mutation, which better transmit temporal relationships in the schedule. The approach produced excellent results on standard benchmark job shop scheduling problems. We further tested many models and scales of parallel GAs in the context of job shop...

We apply the phase field crystal model to study the structure and energy of symmetric tilt grain boundaries of bcc iron in 3D. The parameters for the model are obtained by using a recently developed eight-order fitting scheme [A. Jaatinen et al., (2009)]. The grain boundary free energies we obtain from the model are in good agreement with previous results from molecular dynamics simulations and...

A phase field model for grain growth in materials containing inert, immobile particles has been implemented. Large scale 2D-simulations were performed for different sizes and volume fractions of the second-phase particles and different initial grain sizes of the matrix phase. For all simulations the mean grain size and the number of particles located on grain boundaries as a function of time we...

Grain loss in the harvesting process of combine harvesters not only causes economic losses to farmers but also affects soil environment because lost grain covering soil, influencing crop growth next season. sieve loss-monitoring sensors represent an important accessory harvesters, as they can provide current levels for operator adopt a rational action time serve performance signal control syste...