scholarly journals APPROPRIATE MODELS FOR SIMULATING OPEN-POROUS MATERIALS

2017 ◽  
Vol 36 (2) ◽  
pp. 107 ◽  
Author(s):  
Tomasz Wejrzanowski ◽  
Samih Haj Ibrahim ◽  
Jakub Skibinski ◽  
Karol Cwieka ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Porous Materials ◽  
Pore Size ◽  
Open Porosity ◽  
Diameter Distribution ◽  
Cell Diameter ◽  
Micro Computed Tomography ◽  
Open Cell ◽  
Geometrical Features ◽  
Open Cell Foams ◽  
Number Of Faces

In the present paper two representative models applied for modeling of two types of porous materials - open-cell foams and open-porosity tapes - are addressed. Algorithms presented here base on Laguerre-Voronoi tessellations (open-cell foams) and the sphere representation (open-porosity tapes) and enable creating the desired porosity and pore size distribution. The geometrical features of the models, such as: porosity, mean pore size, cell diameter distribution and number of faces per cell were compared with those obtained by 3D micro-computed tomography and good agreement was obtained.

Design of Reservoir Recognition Technique Component - Open Porosity in Non-Polarizing Electrodes

2017 ◽  
Vol 890 ◽  
pp. 308-311
Author(s):  
Jakub Skibinski ◽  
Tomasz Wejrzanowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Porous Materials ◽  
Pore Size ◽  
Open Porosity ◽  
Complex Geometry ◽  
Size Variation ◽  
Design Procedure ◽  
Ceramic Materials ◽  
Geometrical Features ◽  
Materials Used ◽  
Volume Method

In the present study modeling of permeability of open-porosity ceramic materials used in non-polarizing electrodes is addressed. The structure of the material filling the electrode determines the infiltration of the ceramic structure by electrolyte, which influences the efficiency of the electrodes. The composition of electrode material was characterized with Scanning Electron Microscope Hitachi S3500N with EDS detector and the structure was determined with use of XRadia XCT400 tomograph . The complex geometry of porous materials has been designed using procedure based on Laguerre-Voronoi tessellations (LVT). A set of porous structures with different geometrical features has been developed using LVT algorithm. The approach used here allows to investigate the influence of geometrical features such pore size variation on the permeability of studied materials. Pressure drop characteristics of the developed structures has been analyzed using finite volume method (FVM). The results show that permeability of porous materials is strongly related with distribution of pore size. The study exhibits the utility of developed design procedure for optimization of non-polarizing electrodes performance.

Analysis of variability in additive manufactured open cell porous structures

2017 ◽  
Vol 231 (6) ◽  
pp. 534-546
Author(s):  
Sam Evans ◽  
Eric Jones ◽  
Pete Fox ◽  
Chris Sutcliffe
Keyword(s):  
Porous Material ◽  
Pore Size ◽  
Porous Structures ◽  
Micro Computed Tomography ◽  
Microscopy Imaging ◽  
Geometric Properties ◽  
Open Cell ◽  
Material Thickness ◽  
Cell Structures ◽  
The Mean

In this article, a novel method of analysing build consistency of additively manufactured open cell porous structures is presented. Conventionally, methods such as micro computed tomography or scanning electron microscopy imaging have been applied to the measurement of geometric properties of porous material; however, high costs and low speeds make them unsuitable for analysing high volumes of components. Recent advances in the image-based analysis of open cell structures have opened up the possibility of qualifying variation in manufacturing of porous material. Here, a photogrammetric method of measurement, employing image analysis to extract values for geometric properties, is used to investigate the variation between identically designed porous samples measuring changes in material thickness and pore size, both intra- and inter-build. Following the measurement of 125 samples, intra-build material thickness showed variation of ±12%, and pore size ±4% of the mean measured values across five builds. Inter-build material thickness and pore size showed mean ranges higher than those of intra-build, ±16% and ±6% of the mean material thickness and pore size, respectively. Acquired measurements created baseline variation values and demonstrated techniques suitable for tracking build deviation and inspecting additively manufactured porous structures to indicate unwanted process fluctuations.

The influence of pore size variation on the pressure drop in open-cell foams

2015 ◽  
Vol 87 ◽  
pp. 650-655 ◽  
Author(s):  
Jakub Skibinski ◽  
Karol Cwieka ◽  
Tadeusz Kowalkowski ◽  
Bartlomiej Wysocki ◽  
Tomasz Wejrzanowski ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Pore Size ◽  
Size Variation ◽  
Open Cell ◽  
Open Cell Foams

scholarly journals Micro-Computed Tomography and Finite Element Method Study of Open-Cell Porous Materials

2015 ◽  
Vol 30 ◽  
pp. 03006
Author(s):  
Tomasz Wejrzanowski ◽  
Jakub Skibinski ◽  
Karol Cwieka ◽  
Krzysztof J. Kurzydlowski
Keyword(s):  
Computed Tomography ◽  
Finite Element Method ◽  
Finite Element ◽  
Porous Materials ◽  
Micro Computed Tomography ◽  
Open Cell ◽  
Element Method

scholarly journals The Influence of the Washcoat Deposition Process on High Pore Density Open Cell Foams Activation for CO Catalytic Combustion

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 510 ◽  
Author(s):  
Matteo Ambrosetti ◽  
Riccardo Balzarotti ◽  
Cinzia Cristiani ◽  
Gianpiero Groppi ◽  
Enrico Tronconi
Keyword(s):  
Spin Coating ◽  
Catalytic Combustion ◽  
Active Phase ◽  
Deposition Process ◽  
Dip Coating ◽  
Cell Diameter ◽  
High Porosity ◽  
Pore Density ◽  
Open Cell ◽  
Open Cell Foams

Spin coating was evaluated as alternative deposition technique to the commonly used dip coating procedure for washcoat deposition on high-porosity metallic substrates. By using spin coating, the washcoating of metallic open cell foams with very high pore density (i.e., 580 μm in cell diameter) was finely controlled. Catalytic performances of samples prepared with conventional dip coating and spin coating were evaluated in CO catalytic combustion in air, using palladium as active phase and cerium oxide as carrier. The incipient wetness method was used to prepare catalytic powder, which was dispersed by means of an acid-free dispersing medium. After washcoating, deposited layers were evaluated by optical microscopy and adhesion test. In comparison to dip-coated samples, the use of spin coating demonstrated better performances from both catalytic and coating quality points of view, highlighting the possibility of the industrial adoption of these supports for process intensification in several catalytic applications.

scholarly journals Photogrammetric analysis of additive manufactured metallic open cell porous structures

2018 ◽  
Vol 24 (8) ◽  
pp. 1380-1391 ◽  
Author(s):  
Samuel Evans ◽  
Eric Jones ◽  
Peter Fox ◽  
Chris Sutcliffe
Keyword(s):  
Pore Size ◽  
Low Cost ◽  
High Volume ◽  
Porous Structures ◽  
Micro Computed Tomography ◽  
Open Cell ◽  
Content Type ◽  
Material Thickness ◽  
Computed Tomography Scanning ◽  
Photogrammetric Method

PurposeThis paper aims to introduce a novel method for the analysis of open cell porous components fabricated by laser-based powder bed metal additive manufacturing (AM) for the purpose of quality control. This method uses photogrammetric analysis, the extraction of geometric information from an image through the use of algorithms. By applying this technique to porous AM components, a rapid, low-cost inspection of geometric properties such as material thickness and pore size is achieved. Such measurements take on greater importance, as the production of porous additive manufactured orthopaedic devices increases in number, causing other, slower and more expensive methods of analysis to become impractical.Design/methodology/approachHere the development of the photogrammetric method is discussed and compared to standard techniques including scanning electron microscopy, micro computed tomography scanning and the recently developed focus variation (FV) imaging. The system is also validated against test graticules and simple wire geometries of known size, prior to the more complex orthopaedic structures.FindingsThe photogrammetric method shows an ability to analyse the variability in build fidelity of AM porous structures for use in inspection purposes to compare component properties. While measured values for material thickness and pore size differed from those of other techniques, the new photogrammetric technique demonstrated a low deviation when repeating measurements, and was able to analyse components at a much faster rate and lower cost than the competing systems, with less requirement for specific expertise or training.Originality/valueThe advantages demonstrated by the image-based technique described indicate the system to be suitable for implementation as a means of in-line process control for quality and inspection applications, particularly for high-volume production where existing methods would be impractical.

scholarly journals Incorporation of the Pore Size Variation to Modeling of the Elastic Behavior of Metallic Open-Cell Foams

2017 ◽  
Vol 62 (1) ◽  
pp. 259-262 ◽  
Author(s):  
K. Ćwieka ◽  
T. Wejrzanowski ◽  
K. J. Kurzydłowski
Keyword(s):  
Pore Size ◽  
Size Variation ◽  
Elastic Behavior ◽  
Design Stage ◽  
Metallic Foams ◽  
Compression Tests ◽  
Voronoi Tessellations ◽  
Open Cell ◽  
Open Cell Foams ◽  
Uniform Pore Size

Abstract In the present paper we present the approach for modeling of the elastic behavior of open-cell metallic foams concerning non-uniform pore size distribution. This approach combines design of foam structures and numerical simulations of compression tests using finite element method (FEM). In the design stage, Laguerre-Voronoi tessellations (LVT) were performed on several sets of packed spheres with defined variation of radii, bringing about a set of foam structures with porosity ranging from 74 to 98% and different pore size variation quantified by the coefficient of pore volume variation, CV(V), from 0.5 to 2.1. Each structure was numerically subjected to uni-axial compression test along three directions within the elastic region. Basing on the numerical response, the effective Young’s modulus, Eeff, was calculated for each structure. It is shown that the Eeff is not only dependent on the porosity but also on the pore size variation.

scholarly journals STATISTICAL ANALYSIS OF THE LOCAL STRUT THICKNESS OF OPEN CELL FOAMS

2013 ◽  
Vol 32 (1) ◽  
pp. 1 ◽  
Author(s):  
André Liebscher ◽  
Claudia Redenbach
Keyword(s):  
Euclidean Distance ◽  
Interconnected Network ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Open Cell ◽  
Strut Thickness ◽  
Thickness Profile ◽  
Open Cell Foams ◽  
Polynomial Models ◽  
Sectional Shape

Open cell foams are formed by an interconnected network of struts whose thickness varies locally. These variations were shown to have an impact on the elastic and thermal properties of the foam. In this paper we quantify the local strut thickness by means of micro computed tomography (µCT) imaging. We introduce a skeletonization based topological decomposition of the foam structure into its vertices and struts. This allows to estimate the thickness of individual strut segments by the Euclidean distance transform, where an appropriate correction for struts with nonspherical cross-sectional shape is applied. Conflating these estimates based on the strut lengths results in a strut thickness profile for the entire foam. Polynomial models for the strut thickness profile are investigated by means of a regression analysis.

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