Foam Structure: From Soap Froth to Solid Foams

MRS Bulletin ◽  
2003 ◽  
Vol 28 (4) ◽  
pp. 275-278 ◽  
Author(s):  
Andrew M. Kraynik
Keyword(s):  
Three Dimensional ◽  
Edge Length ◽  
Surface Evolver ◽  
Foam Structure ◽  
Open Cell ◽  
Liquid Foams ◽  
Virtual Reconstruction ◽  
Open Cell Foams ◽  
Solid Foams ◽  
Polyhedral Cells

AbstractThe properties of solid foams depend on their structure, which usually evolves in the fluid state as gas bubbles expand to form polyhedral cells. The characteristic feature of foam structure—randomly packed cells of different sizes and shapes—is examined in this article by considering soap froth. This material can be modeled as a network of minimal surfaces that divide space into polyhedral cells. The cell-level geometry of random soap froth is calculated with Brakke's Surface Evolver software. The distribution of cell volumes ranges from monodisperse to highly polydisperse. Topological and geometric properties, such as surface area and edge length, of the entire foam and individual cells, are discussed. The shape of struts in solid foams is related to Plateau borders in liquid foams and calculated for different volume fractions of material. The models of soap froth are used as templates to produce finite element models of open-cell foams. Three-dimensional images of open-cell foams obtained with x-ray microtomography allow virtual reconstruction of skeletal structures that compare well with the Surface Evolver simulations of soap-froth geometry.

Elastic Wave Propagation in Open-Cell Foams

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Alireza Bayat ◽  
Stavros Gaitanaros
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Finite Size ◽  
Bloch Wave ◽  
Elastic Wave Propagation ◽  
Surface Evolver ◽  
Dynamic Simulations ◽  
Element Analysis ◽  
Open Cell ◽  
Open Cell Foams

This work examines elastic wave propagation phenomena in open-cell foams with the use of the Bloch wave method and finite element analysis. Random foam topologies are generated with the Surface Evolver and subsequently meshed with Timoshenko beam elements, creating open-cell foam models. Convergence studies on band diagrams of different domain sizes indicate that a representative volume element (RVE) consists of at least 83 cells. Wave directionality and energy flow features are investigated by extracting phase and group velocity plots. Explicit dynamic simulations are performed on finite size domains of the considered foam structure to validate the RVE results. The effect of topological disorder is studied in detail, and excellent agreement is found between the wave behavior of the random foam and that of both the regular and perturbed Kelvin foams in the low-frequency regime. In higher modes and frequencies, however, as the wavelengths become smaller, disorder has a significant effect and the deviation between regular and random foam increases significantly.

scholarly journals Coating of polydopamine on polyurethane open cell foams to design soft structured supports for molecular catalysts

2019 ◽  
Vol 55 (79) ◽  
pp. 11960-11963 ◽  
Author(s):  
Ahmed Ait Khouya ◽  
Miguel L. Mendez Martinez ◽  
Philippe Bertani ◽  
Thierry Romero ◽  
Damien Favier ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Open Cell ◽  
Covalent Grafting ◽  
Open Cell Foams ◽  
Molecular Catalysts

A covalent grafting strategy of molecular catalysts onto a polydopamine-coated flexible three dimensional macroscopic support is presented.

Analysis of Heat Transfer and Pressure Drop Through Idealized Open Cell Ceramic Foams: Comparison Between Kelvin and Weaire-Phelan Cell Structures

2013 ◽  
Author(s):  
N. Bianco ◽  
S. Cunsolo ◽  
W. K. S. Chiu ◽  
V. Naso ◽  
A. Migliozzi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Open Source Software ◽  
Surface Evolver ◽  
Open Cell ◽  
Ceramic Foams ◽  
Cell Structures ◽  
Cell Architecture ◽  
Cell Dimensions ◽  
Open Cell Foams

In the applications of metal foams, the knowledge of the thermal transport properties is of primary importance. Thermal properties of a foam heavily depend on its microstructure. However, the influence of some geometric characteristics of the foam cells on their properties is far from being understood. Foam models are promising tools to study the above said effects. The effect of the cell architecture on heat transfer and pressure drop in open cell foams is investigated numerically using two foam models. The Kelvin and the Weaire-Phelan foam models are developed in an open source software “Surface Evolver”. Heat transfer and pressure drop in samples with different porosities and cell dimensions are studied using COMSOL® Multiphysics. Finally, a comparison between the numerical results obtained from two foam models is carried out in order to evaluate the feasibility to substitute the Weaire-Phelan foam structure, which is more complex and computationally heavier, with the simpler Kelvin foam representation.

Nonlinear Modeling of 3D Open-Cell Foams

1999 ◽  
Author(s):  
Yu Wang ◽  
Alberto M. Cuitiño
Keyword(s):  
Strain Energy ◽  
Nonlinear Modeling ◽  
Three Dimensional ◽  
Strain Energy Function ◽  
Nonlinear Material ◽  
Open Cell ◽  
Wide Range ◽  
Open Cell Foams ◽  
Explicit Correlation ◽  
Strain Energy Functions

Abstract In this article, we present a hyperelastic model for light and compliant open cell foams with an explicit correlation between microstructure and macroscopic behavior. The model describes a large number of three dimensional structures with regular and irregular cells. The theory is based on the formulation of strain-energy function accounting for stretching which is the main deformation mechanism in this type of materials. Within the same framework, however, bending, shear and twisting energies can also be incorporated. The formulation incorporates nonlinear kinematics which traces the evolution of the structure during loading process and its effects on the constitutive behavior, including the cases where configurational transformations are present leading to non-convex strain-energy functions. Also nonlinear material effects at local or beam level are introduced to accommodate a wide range of different material behaviors. Since the micromechanical formulation presented here has explicit correlation with the foam structure, it preserves in the constitutive relation the symmetries or directional properties of the corresponding structures, including the cases of re-entrant foams which exhibit negative Poisson’s ratio effects. The model captures the central features exhibit by these materials. Predictions of the model for macroscopic uniaxial strain are presented in this article.

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