A three‐dimensional staggered finite element approach for random parametric modeling of thermo‐hygral coupled phenomena in porous media

Abstract

The aim of this paper is to present a three-dimensional (3D) finite element modeling of heat and mass transfer phenomena in partially saturated open porous media with random fields of material properties. Randomness leads to transfer processes within the porous medium that naturally need a full 3D modeling for any quantitative assessment of these processes. Nevertheless, the counterpart of 3D modeling is a significant increase in computations cost. Therefore, a staggered solution strategy is adopted which permits to solve the equations sequentially. This appropriate partitioning reduces the size of the discretized problem to be solved at each time step. It is based on a specific iterative algorithm to account for the interaction between all the transfer processes. Accordingly, a suitable linearization of mass convective boundary conditions, consistent with the staggered algorithm, is also derived. After some validation tests, the 3D numerical model is used for studying the drying process of a cementitious material with regard to its intrinsic permeability randomness

Composite behavior of concrete materials under high temperatures

“…16) in concrete, can be captured via a macroscopic approach only if referring to more sophisticated models as e.g. Meftah et al (2012); additionally, Fig. 15(d) shows the three-dimensionality of stress distribution, not visible when using 2D models.…”

Probabilistic Assessment of Randomly Heterogeneous Soil Slopes

“…Zhang (1999), Tartakovsky et al (2003), Yang et al (2004), Lu and Zhang (2007), Li et al (2009), Mousavi Nezhad et al (2011, Cho (2012), Le et al (2012), and Meftah et al (2012) among others, analyzed unsaturated flow in heterogeneous soils with spatially distributed uncertain hydraulic parameters. Some researchers have considered the spatial variability for the problem of flow in unsaturated soil and slope stability.…”

Effect of high temperatures on cement composite materials in concrete structures

“…Water gets gradually loose from the material. First, free water from cement paste evaporates through capillaries and then chemically bounded water leaves the material (Meftah et al, 2012). Nevertheless, hydrothermal reaction can occur causing considerable physical and chemical changes in microstructure (internal autoclaving) if cement paste is heated in enclosed and humid environment.…”