@misc{HombergBaumWiebeletal.2013, author = {Homberg, Ulrike and Baum, Daniel and Wiebel, Alexander and Prohaska, Steffen and Hege, Hans-Christian}, title = {Definition, Extraction, and Validation of Pore Structures in Porous Materials}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-42510}, year = {2013}, abstract = {An intuitive and sparse representation of the void space of porous materials supports the efficient analysis and visualization of interesting qualitative and quantitative parameters of such materials. We introduce definitions of the elements of this void space, here called pore space, based on its distance function, and present methods to extract these elements using the extremal structures of the distance function. The presented methods are implemented by an image processing pipeline that determines pore centers, pore paths and pore constrictions. These pore space elements build a graph that represents the topology of the pore space in a compact way. The representations we derive from μCT image data of realistic soil specimens enable the computation of many statistical parameters and, thus, provide a basis for further visual analysis and application-specific developments. We introduced parts of our pipeline in previous work. In this chapter, we present additional details and compare our results with the analytic computation of the pore space elements for a sphere packing in order to show the correctness of our graph computation.}, language = {en} } @article{VincensWittHomberg2015, author = {Vincens, Eric and Witt, Karl Josef and Homberg, Ulrike}, title = {Approaches to Determine the Constriction Size Distribution for Understanding Filtration Phenomena in Granular Materials}, volume = {10}, journal = {Acta Geotechnica}, number = {3}, publisher = {Springer}, doi = {10.1007/s11440-014-0308-1}, pages = {291 -- 303}, year = {2015}, language = {en} } @article{SeblanyHombergVincensetal.2018, author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for defining pores and constrictions in numerical packing of spheres}, volume = {20}, journal = {Granular Matter}, number = {37}, publisher = {Springer Berlin Heidelberg}, issn = {1434-5021}, doi = {10.1007/s10035-018-0808-z}, year = {2018}, abstract = {The void space of granular materials is generally divided into larger local volumes denoted as pores and throats connecting pores. The smallest section in a throat is usually denoted as constriction. A correct description of pores and constrictions may help to understand the processes related to the transport of fluid or fine particles through granular materials, or to build models of imbibition for unsaturated granular media. In the case of numerical granular materials involving packings of spheres, different methods can be used to compute the pore space properties. However, these methods generally induce an over-segmentation of the pore network and a merging step is usually applied to mitigate such undesirable artifacts even if a precise delineation of a pore is somewhat subjective. This study provides a comparison between different merging criteria for pores in packing of spheres and a discussion about their implication on both the pore size distribution and the constriction size distribution of the material. A correspondence between these merging techniques is eventually proposed as a guide for the user.}, language = {en} } @misc{SeblanyHombergVincensetal.2018, author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for defining pores and constrictions in numerical packing of spheres}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-69158}, year = {2018}, abstract = {The void space of granular materials is generally divided into larger local volumes denoted as pores and throats connecting pores. The smallest section in a throat is usually denoted as constriction. A correct description of pores and constrictions may help to understand the processes related to the transport of fluid or fine particles through granular materials, or to build models of imbibition for unsaturated granular media. In the case of numerical granular materials involving packings of spheres, different methods can be used to compute the pore space properties. However, these methods generally induce an over-segmentation of the pore network and a merging step is usually applied to mitigate such undesirable artifacts even if a precise delineation of a pore is somewhat subjective. This study provides a comparison between different merging criteria for pores in packing of spheres and a discussion about their implication on both the pore size distribution and the constriction size distribution of the material. A correspondence between these merging techniques is eventually proposed as a guide for the user.}, language = {en} } @inproceedings{SeblanyHombergVincensetal.2017, author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for the definition of a local pore and the CSD computation of granular materials}, booktitle = {Proceedings of the 25th meeting of the Working Group on Internal Erosion in embankment dams and their foundations}, publisher = {Deltares}, address = {Delft, Netherlands}, isbn = {978-90-827468-1-5 | 978-90-827468-0-8}, pages = {150 -- 159}, year = {2017}, language = {en} } @misc{SeblanyHombergVincensetal.2018, author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for the definition of a local pore and the CSD computation of granular materials}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-67069}, year = {2018}, language = {en} } @misc{HombergBaumWiebeletal.2014, author = {Homberg, Ulrike and Baum, Daniel and Wiebel, Alexander and Prohaska, Steffen and Hege, Hans-Christian}, title = {Definition, Extraction, and Validation of Pore Structures in Porous Materials}, journal = {Topological Methods in Data Analysis and Visualization III}, editor = {Bremer, Peer-Timo and Hotz, Ingrid and Pascucci, Valerio and Peikert, Ronald}, publisher = {Springer}, doi = {10.1007/978-3-319-04099-8_15}, pages = {235 -- 248}, year = {2014}, language = {en} } @inproceedings{HombergBaumProhaskaetal.2012, author = {Homberg, Ulrike and Baum, Daniel and Prohaska, Steffen and Kalbe, Ute and Witt, Karl Josef}, title = {Automatic Extraction and Analysis of Realistic Pore Structures from µCT Data for Pore Space Characterization of Graded Soil}, booktitle = {Proceedings of the 6th International Conference on Scour and Erosion (ICSE-6)}, pages = {345 -- 352}, year = {2012}, language = {en} } @inproceedings{BinnerHombergProhaskaetal.2010, author = {Binner, Richard and Homberg, Ulrike and Prohaska, Steffen and Kalbe, Ute and Witt, Karl Josef}, title = {Identification of Descriptive Parameters of the Soil Pore Structure using Experiments and CT Data}, booktitle = {Proceedings of the 5th International Conference on Scour and Erosion (ICSE-5)}, publisher = {American Society of Civil Engineers (ASCE)}, pages = {397 -- 407}, year = {2010}, language = {en} } @inproceedings{HombergBaumProhaska2011, author = {Homberg, Ulrike and Baum, Daniel and Prohaska, Steffen}, title = {Describing and Analyzing the Dual Structures of Porous Media}, booktitle = {Proc. 3D-Microstructure Meeting}, editor = {M{\"u}cklich, Frank and Slussallek, Philipp and Schladitz, Katja}, pages = {24 -- 25}, year = {2011}, language = {en} } @inproceedings{HombergBinnerProhaskaetal.2009, author = {Homberg, Ulrike and Binner, Richard and Prohaska, Steffen and Dercksen, Vincent J. and Kuß, Anja and Kalbe, Ute}, title = {Determining Geometric Grain Structure from X-Ray Micro-Tomograms of Gradated Soil}, volume = {21}, booktitle = {Workshop Internal Erosion}, pages = {37 -- 52}, year = {2009}, language = {en} }