Foamed concrete simulation

16 September 2014

by Pierre Lafortune, Idra Simulation, member of Code_Aster ProNet

Idra Simulation offers services in numerical simulation and finite element analysis, it works with different industry sectors, but also with scientific and academic institutions.

Foamed concrete is produced by introducing macroscopic air voids of approximately 0.1 to 1 mm in cement paste. This study investigates the effect of air content on the mechanical properties of foamed concrete.

Figure 1 : foamed concrete sample

A program written in Octave calculates the arrangement of the voids according to certain parameters (air content, packing configuration, size, etc). It seeks to place a predetermined quantity of spheres inside a cube. As the spheres should not touch each other, the program iterates until it reaches the desired porosity.

Then, it produces some code to create this geometry in SALOME. They are simply the spheres to be extracted from the cube to create the “holes”: 

v1= geompy.MakeVertex(612.182623,485.772024,594.004208)

s1= geompy.MakeSpherePntR(v1 ,78.500000 )

v2= geompy.MakeVertex(560.181874,688.394585,218.552426)

s2= geompy.MakeSpherePntR(v2 ,78.500000 )

Finally, a compression test is performed with Code_Aster.
This sequence of operations is integrated within a shell script. This methodology allows automatic generation of a large number of configurations and underlines the flexibility of the software used at Idra Simulation.

Figure 2 : Octave-SALOME-Code_Aster sequence

Bibliography :
 [1] Air-Void System of Foamed Concrete and its Effect on Mechanical Properties
by Tiong-Huan Wee, Daneti Saradhi Babu, T. Tamilselvan, and Hwee-Sin Lim - ACI Materials Journal/January-February 2006
 [2] Young’s Modulus of Macroporous Bioceramics: Measurement and Numerical Simulation
par François Pecqueux,1,2 Franck Tancret,1 and Jean-Michel Bouler Polytech-Nantes et INSERM UMR791
Ashdin Publishing - Bioceramics Development and Applications - 2010