Representative elementary volume

About: Representative elementary volume is a research topic. Over the lifetime, 4105 publications have been published within this topic receiving 86863 citations.

Mesoscale bounds in finite elasticity and thermoelasticity of random composites

Abstract: Under consideration is the problem of size and response of the Representative Volume Element (RVE) in the setting of finite elasticity of statistically homogeneous and ergodic random microstructures. Through the application of variational principles, a scale dependent hierarchy of strain energy functions (i.e. mesoscale bounds) is derived for the effective strain energy function of the RVE. In order to account for thermoelastic effects, the variational principles are first generalized, and then analogous bounds on the effective thermoelastic response are derived. It is also shown that, in contradiction to results obtained for random linear composites, the hierarchy on the effective strain energy function in nonlinear elasticity cannot be split into volumetric and isochoric terms, while the hierarchy on the effective free energy function cannot be divided into purely mechanical and thermal contributions.

Modelling the elastic properties of softwood : Part I: The cell-wall lamellae (Originalarbeiten)

Abstract: A procedure for determining the nine equivalent orthotropic elastic constants for a cell-wall lamella is presented. A two-stage analytic homogenization method is proposed. It is shown to give results which are similar to those obtained from a full numerical finite element solution for an idealised representative volume element. The method, which can accommodate arbitrary proportions of cell wall constituents, is used to determine the equivalent elastic constants for lamellae in the secondary cell wall layers and the compound middle lamella of a typical softwood tracheid at a nominal 12% moisture Content.

Pore-to-core simulations of flow with large velocities using continuum models and imaging data

Abstract: We consider computational modeling of flow with small and large velocities at porescale and at corescale, and we address various challenges in simulation, upscaling, and modeling. While our focus is on voxel-based data sets from real porous media imaging, our methodology is verified first on synthetic geometries, and we analyze various scaling and convergence properties. We show that the choice of a voxel-based grid and representative elementary volume size can lead up to 10–20 % difference in calculated conductivities. On the other hand, the conductivities decrease significantly with flow rates, starting in a regime usually associated with the onset of inertia effects. This is accompanied by deteriorating porescale solver performance, and we continue our experiments up until about 50 % reduction in conductivities, i.e., to Reynolds number just under 1. To account for this decrease, we propose a practical power-based fully anisotropic non-Darcy model at corescale for which we calculate the parameters by upscaling.