TY - GEN A1 - Homberg, U. A1 - Binner, Richard A1 - Prohaska, S. A1 - Dercksen, V.J. A1 - Kuß, A. A1 - Kalbe, Ute ED - Witt, Karl Josef T1 - Determining geometric grain structure from X-ray micro-tomograms of gradated soil T2 - Workshop "Internal Erosion" CY - Weimar, Germany DA - 2008-11-26 KW - Gradated soil KW - Suffosive erosion phenomena KW - Pore and grain structure KW - Micro computed tomography KW - Morphologic image processing PY - 2008 SN - 978-3-86068-392-7 N1 - Serientitel: Schriftenreihe Geotechnik – Series title: Schriftenreihe Geotechnik IS - 21 SP - 37 EP - 52 PB - Bauhaus-Univ. CY - Weimar AN - OPUS4-19866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Semar, O. A1 - Binner, Richard A1 - Homberg, U. A1 - Kalbe, Ute A1 - Mehlhorn, T. A1 - Prohaska, S. A1 - Slowik, V. A1 - Witt, K. J. ED - Witt, K. J. T1 - Conditions for suffosive erosion phenomena in soils - concept and approach - T2 - Workshop "Internal Erosion" CY - Weimar, Germany DA - 2008-11-26 KW - Pore KW - Pore throat KW - Constriction sizes KW - CT-scan KW - Modelling PY - 2008 SN - 978-3-86068-392-7 N1 - Serientitel: Schriftenreihe Geotechnik – Series title: Schriftenreihe Geotechnik IS - 21 SP - 29 EP - 35 PB - Bauhaus-Univ. CY - Weimar AN - OPUS4-19867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Homberg, U. A1 - Baum, D. A1 - Prohaska, S. A1 - Günster, Jens A1 - Krauss-Schüler, Stefanie T1 - Adapting trabecular structures for 3D printing: an image processing approach based on μCT data N2 - Materials with a trabecular structure notably Combine advantages such as lightweight, reasonable strength, and permeability for fl uids. This combination of advantages is especially interesting for tissue engineering in trauma surgery and orthopedics. Bone-substituting scaffolds for instance are designed with a trabecular structure in order to allow cell migration for bone ingrowth and vascularization. An emerging and recently very popular technology to produce such complex, porous structures is 3D printing. However, several technological aspects regarding the scaffold architecture, the printable resolution, and the feature size have to be considered when fabricating scaffolds for bone tissue replacement and regeneration. Here, we present a strategy to assess and prepare realistic trabecular structures for 3D printing using image analysis with the aim of preserving the structural elements. We discuss critical conditions of the printing system and present a 3-stage approach to adapt a trabecular structure from μ CT data while incorporating knowledge about the printing system. In the first stage, an image-based extraction of solid and void structures is performed, which results in voxel- and graph-based representations of the extracted structures. These representations not only allow us to quantify geometrical properties such as pore size or strut geometry and length. But, since the graph represents the geometry and the topology of the initial structure, it can be used in the second stage to modify and adjust feature size, volume and sample size in an easy and consistent way. In the final reconstruction stage, the graph is then converted into a voxel representation preserving the topology of the initial structure. This stage generates a model with respect to the printing conditions to ensure a stable and controlled voxel placement during the printing process. KW - Additive manufacturing, 3D printing KW - Trabecular structures KW - Image-based analysis PY - 2017 DO - https://doi.org/10.1088/2057-1976/aa7611 SN - 2057-1976 VL - 3 IS - 3 SP - Article 035027, 1 EP - 14 PB - IOP Publishing Ltd AN - OPUS4-40744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Homberg, U. A1 - Baum, D. A1 - Prohaska, S. A1 - Kalbe, Ute A1 - Witt, K. J. T1 - Automatic extraction and analysis of realistic pore structures from muCT data for pore space characterization of graded soil N2 - We present image-based methods to extract and analyze the pore structure of graded soil from CT scans. To assess and characterize realistic pore structures of graded soil, we process data of hetero disperse granulär material acquired via high-resolut ion CT. Real soil material configures a pore space with irregulär formations and complex arrangements. In Order to derive parameters of the pore space, a compact representation of the complex pore structure and efficient analysis methods are required. For this purpose, we propose mathematical definitions of the pore structure elements like pore centers, pore paths, pore constrictions, and pore bodies. These definitions are based on the distance map given on the Segmentation of the soil material into particles andpore space. For the extraction of the deftned structure elements, we present two image-basedprocessing pipelines that use the correspondence between our distance-based definition of pore structure elements and a Voronoi decomposition of the pore space. From the extractedpore centers andpore paths, we construct a graph and encode the distance Information on it. This graph, which we call the pore graph, is a compact 3d-representation of the topology of the pore space and provides a good basis to apply efficient graph-based methods for quantification as well as visualization and exploration of the spatial relationships and Connectivity of the pore space. T2 - ICSE6 - 6th International conference on scour and erosion CY - Paris, France DA - 27.08.2012 KW - Microtomography KW - Image analysis KW - Pore structure KW - Pore constriction KW - Suffosion KW - Graded soil PY - 2012 IS - ICSE6-181 SP - 345 EP - 352 AN - OPUS4-26965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -