Representative unit-cell models for open-cell metal foams with or without elastic filler

2003 ◽  
Vol 343 (1-2) ◽  
pp. 63-70 ◽  
Author(s):  
Y.W. Kwon ◽  
R.E. Cooke ◽  
C. Park
Keyword(s):  
Metal Foams ◽  
Unit Cell ◽  
Cell Models ◽  
Open Cell ◽  
Representative Unit Cell ◽  
Elastic Filler

An Analytical Unit Cell Model for the Effective Thermal Conductivity of High Porosity Open-Cell Metal Foams

2014 ◽  
Vol 102 (3) ◽  
pp. 403-426 ◽  
Author(s):  
Xiao Hu Yang ◽  
Jia Xi Bai ◽  
Hong Bin Yan ◽  
Jiu Jie Kuang ◽  
Tian Jian Lu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Cell Model ◽  
Metal Foams ◽  
Unit Cell ◽  
High Porosity ◽  
Unit Cell Model ◽  
Open Cell

scholarly journals Simulation of Thermal Transport in Open-Cell Metal Foams: Effect of Periodic Unit Cell Structure

2006 ◽  
Author(s):  
Shankar Krishnan ◽  
Suresh V. Garimella ◽  
Jayathi Y. Murthy
Keyword(s):  
Thermal Transport ◽  
Pore Space ◽  
Cell Structure ◽  
Flow Characteristics ◽  
Metal Foams ◽  
Unit Cube ◽  
Unit Cell ◽  
Face Centered Cubic ◽  
Open Cell ◽  
Periodic Unit Cell

Direct simulation of thermal transport in open-cell metal foams is conducted using different periodic unit cell geometries. The periodic unit cell structures are constructed by assuming the pore space to be spherical and subtracting the pore space from a unit cube of the metal. Different types of packing arrangement for spheres are considered - Body Centered Cubic, Face Centered Cubic, and the A15 lattice (similar to a Weaire-Phelan unit cell) - which give rise to different foam structures. Effective thermal conductivity, pressure drop and Nusselt number are computed by imposing periodic boundary conditions for aluminum foams saturated with air or water. The computed values compare well with existing experimental measurements and semi-empirical models for porosities greater than 80%. The effect of different foam packing arrangements on the computed thermal and fluid flow characteristics is discussed. The capabilities and limitations of the present approach are identified.

Electrical Conductivity of Open-cell Metal Foams

2002 ◽  
Vol 17 (3) ◽  
pp. 625-631 ◽  
Author(s):  
K. P. Dharmasena ◽  
H. N. G. Wadley
Keyword(s):  
Electrical Conductivity ◽  
Relative Density ◽  
Linear Dependence ◽  
Aluminum Foam ◽  
Cell Model ◽  
Low Frequency ◽  
Metal Foams ◽  
Unit Cell ◽  
Cross Sectional ◽  
Open Cell

Cellular metal foams are of interest because of the ability to tailor their mechanical, thermal, acoustic, and electrical properties by varying the relative density and cell morphology. Here, a tetrakaidecahedral unit-cell approach is used to represent an open-cell aluminum foam and a simplified electrical resistor network derived to model low frequency current flow through the foam. The analysis indicates that for the range of relative densities studied (4–12%), the conductivity of tetrakaidecahedral foams has a linear dependence upon relative density. The distribution of metal in the cell ligaments was found to significantly affect the conductivity. Increasing the fraction of metal at the ends of the ligaments resulted in a decrease in electrical conductivity at a fixed relative density. Low frequency electrical conductivity measurements of an open-cell aluminum foam (ERG Duocel) confirmed the linear dependence upon density, but the slope was smaller than that predicted by the unit-cell model. The difference between the model and experiment was found to be the result of the presence of a distribution of cell sizes and types in real samples. This effect is due to the varying number of ligaments, ligament lengths, and the cross-sectional areas available for current conduction across the cellular structure.

scholarly journals Simulation of Thermal Transport in Open-Cell Metal Foams: Effect of Periodic Unit-Cell Structure

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Shankar Krishnan ◽  
Suresh V. Garimella ◽  
Jayathi Y. Murthy
Keyword(s):  
Thermal Transport ◽  
Pore Space ◽  
Cell Structure ◽  
Flow Characteristics ◽  
Metal Foams ◽  
Unit Cube ◽  
Unit Cell ◽  
Face Centered Cubic ◽  
Open Cell ◽  
Periodic Unit Cell

Direct simulation of thermal transport in open-cell metal foams is conducted using different periodic unit-cell geometries. The periodic unit-cell structures are constructed by assuming the pore space to be spherical and subtracting the pore space from a unit cube of the metal. Different types of packing arrangement for spheres are considered—body centered cubic, face centered cubic, and the A15 lattice (similar to a Weaire-Phelan unit cell)—which give rise to different foam structures. Effective thermal conductivity, pressure drop, and Nusselt number are computed by imposing periodic boundary conditions for aluminum foams saturated with air or water. The computed values compare well with existing experimental measurements and semiempirical models for porosities greater than 80%. The effect of different foam packing arrangements on the computed thermal and fluid flow characteristics is discussed. The capabilities and limitations of the present approach are identified.

3D NUMERICAL INVESTIGATION OF FLUID FLOW THROUGH OPEN-CELL METAL FOAMS USING MICRO-TOMOGRAPHY IMAGES

2014 ◽  
Vol 17 (11) ◽  
pp. 1019-1029 ◽  
Author(s):  
Mohammad Zafari ◽  
Masoud Panjepour ◽  
Mohsen Davazdah Emami ◽  
Mahmood Meratian
Keyword(s):  
Fluid Flow ◽  
Numerical Investigation ◽  
Metal Foams ◽  
Open Cell ◽  
Flow Through ◽  
Micro Tomography

scholarly journals Thermo-Viscoelastic Response of 3D Braided Composites Based on a Novel FsMsFE Method

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Jun-Jun Zhai ◽  
Xiang-Xia Kong ◽  
Lu-Chen Wang
Keyword(s):  
Finite Element ◽  
Cell Model ◽  
Structural Parameters ◽  
Thermal Relaxation ◽  
Viscoelastic Behavior ◽  
Unit Cell ◽  
Time Dependent ◽  
3D Braided Composites ◽  
Equivalent Time ◽  
Representative Unit Cell

A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied.

Geometry Dependent Effective Elastic Properties of Open-Cell Foams Based on Kelvin Cell Models**

2013 ◽  
Vol 15 (12) ◽  
pp. 1292-1298 ◽  
Author(s):  
Johannes Storm ◽  
Martin Abendroth ◽  
Dongshuang Zhang ◽  
Meinhard Kuna
Keyword(s):  
Elastic Properties ◽  
Cell Models ◽  
Open Cell ◽  
Effective Elastic Properties ◽  
Open Cell Foams

Meshfree Continuum Damage Mechanics Modelling for 3D Orthogonal Woven Composites

2011 ◽  
Vol 488-489 ◽  
pp. 759-762
Author(s):  
L.Y. Li ◽  
M.H. Aliabadi ◽  
Pi Hua Wen
Keyword(s):  
Damage Mechanics ◽  
Shape Function ◽  
Cell Model ◽  
Continuum Damage Mechanics ◽  
Unit Cell ◽  
Woven Composites ◽  
Continuum Damage ◽  
Unit Cell Model ◽  
Cell Models ◽  
3D Orthogonal Woven

A Meshfree approach for continuum damage modeling of 3D orthogonal woven composites is presented. Two different shape function constructions, Radial basis (RB) function and Moving kriging (MK) interpolation, are utilized corresponding with Galerkin method in the Meshfree approach. The failure of two different unit cell models, straight-edge and smooth fabric unit cell model respectively, is compared.

CuZnAl Shape Memory Alloys Foams

2012 ◽  
Vol 78 ◽  
pp. 31-39 ◽  
Author(s):  
Ausonio Tuissi ◽  
Paola Bassani ◽  
Carlo Alberto Biffi
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Physical And Mechanical Properties ◽  
Metal Foams ◽  
Cellular Structures ◽  
Metallic Materials ◽  
Open Cell ◽  
Liquid Infiltration ◽  
Highly Porous ◽  
Metal Infiltration

Foams and other highly porous metallic materials with cellular structures are known to have many interesting combinations of physical and mechanical properties. That makes these systems very attractive for both structural and functional applications. Cellular metals can be produced by several methods including liquid infiltration of leachable space holders. In this contribution, results on metal foams of Cu based shape memory alloys (SMAs) processed by molten metal infiltration of SiO2 particles are presented. By using this route, highly homogeneous CuZnAl SMA foams with a spherical open-cell morphologies have been manufactured and tested. Morphological, thermo-mechanical and cycling results are reported.

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