Micromechanics model for three-dimensional open-cell foams using a tetrakaidecahedral unit cell and Castigliano's second theorem

2003 ◽  
Vol 63 (12) ◽  
pp. 1769-1781 ◽  
Author(s):  
K. Li ◽  
X.-L. Gao ◽  
A.K. Roy
2019 ◽  
Vol 55 (79) ◽  
pp. 11960-11963 ◽  
Author(s):  
Ahmed Ait Khouya ◽  
Miguel L. Mendez Martinez ◽  
Philippe Bertani ◽  
Thierry Romero ◽  
Damien Favier ◽  
...  

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


Author(s):  
Sahab Babaee ◽  
Babak Haghpanah Jahromi ◽  
Amin Ajdari ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri

We present a series of analytical models and finite element results (FE) for special 3-D open cellular foam to determine the effective material properties of a 3D rhombic dedecahedron open-cell cellular structure. The analytical approach is based on minimizing the total energy associated with small deformation of a single unit cell of the cellular structure. The finite element models were developed for both a single unit cell and three dimensional foam structure and used to obtain the mechanical properties in all three principal directions.


1999 ◽  
Author(s):  
Yu Wang ◽  
Alberto M. Cuitiño

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.


MRS Bulletin ◽  
2003 ◽  
Vol 28 (4) ◽  
pp. 275-278 ◽  
Author(s):  
Andrew M. Kraynik

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.


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