Combs: open source python library for RVE generation. Application to microscale diffusion simulations in cementitious materials

Abstract

The developed tools are used to create a representative volume element (RVE) of cementitious materials and then assess the diffusive properties. The algorithms developed in Combs target a fast placement of the inclusions and a fast generation of the RVE shape and its mesh. Two application cases are considered: the unaltered material diffusivity and the degraded material diffusivity. The first case of application focuses on the description of the capillary porosity. The second application case focuses on the description of the degradation of cementitious material (mineral and porosity) and the diffusive properties associated. The reliability of the analytical effective medium approximations (MT and SC) is confirmed from 3D finite elements (FE) calculations performed on a matrix-inclusions microstructure obtained by RVE generation with Combs. The results also show the need to take into account the percolation behavior.

Coupled carbonation-rust formation-damage modeling and simulation of steel corrosion in 3D mesoscale reinforced concrete

“…This is believed to be important in particular for estimating the initiation and propagation paths of the cracks, as the behavior of both mortar matrix and aggregates are dissimilar. The geometry and mesh of the mesostructure are generated via a script developed in python language, which makes use of the geometry module and meshing softwares plugged to the integration platform for numerical simulations Salome (www.salome-platform.org) [26,45,46]. Aggregates are modeled by Voronoi particles, whose shape is believed to be more realistic than simpler ones like spheres (see also e.g.…”

Analytical and 3D numerical analysis of the thermoviscoelastic behavior of concrete-like materials including interfaces

“…The procedure for constructing the numerical cubic samples is detailed in [28,47] with triangles for the surfaces (MeshGems-CADSurf) and tetrahedral elements for the volumes (MeshGems-Tetra). As mentioned in the introduction, this procedure has been applied in diverse situations for creating cementitious materials REVs or microstructural elements of concretes exhibiting a free surface exposed to the atmosphere [27][28][29][30].…”

“…. The open-source python library Combs[47] based on the Computer-Aided Design code Salome (http://www.salome -platform.org) is used to generate both geometry and meshes of the mesostructures. Basically, the geometries are obtained by randomly distributing in a box polyhedral aggregates of various sizes…”

Numerical Analysis of Concrete Creep on Mesoscopic 3D Specimens

“…The procedure for constructing the numerical cubic samples is detailed in (Bourcier et al 2013;de Larrard et al 2013). The open-source python library Combs (Bourcier et al 2013) based on the Computer-Aided Design code (Salome) is used to generate both geometry and meshes of the mesostructures. To improve the placement procedure time, the GJK 3D algorithm has been implemented in Combs for fast polyhedrons distance computation (see e.g.…”

“…In this paper we investigate analytically and numerically the creep behavior of concrete at mesoscale. The simulations are carried out on 3D concrete specimens generated by means of python scripts using the functionalities of the integration platform Salome (Bourcier et al 2013;Salome). They consist in about 4600 polyhedral aggregates of various sizes and shapes obtained by a Voronoi space decomposition, and randomly distributed in a box.…”