{ "types" : { "Bookmark" : { "pluralLabel" : "Bookmarks" }, "Publication" : { "pluralLabel" : "Publications" }, "GoldStandardPublication" : { "pluralLabel" : "GoldStandardPublications" }, "GoldStandardBookmark" : { "pluralLabel" : "GoldStandardBookmarks" }, "Tag" : { "pluralLabel" : "Tags" }, "User" : { "pluralLabel" : "Users" }, "Group" : { "pluralLabel" : "Groups" }, "Sphere" : { "pluralLabel" : "Spheres" } }, "properties" : { "count" : { "valueType" : "number" }, "date" : { "valueType" : "date" }, "changeDate" : { "valueType" : "date" }, "url" : { "valueType" : "url" }, "id" : { "valueType" : "url" }, "tags" : { "valueType" : "item" }, "user" : { "valueType" : "item" } }, "items" : [ { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/29a274e01a5b4e2dbffe52ad7ad3d23f1/itke", "tags" : [ "relaxation","2013","knippers","shell","grid","itke","from:petraheim","elastic","dynamic","li","bauingenieurwesen","gitterschale" ], "intraHash" : "9a274e01a5b4e2dbffe52ad7ad3d23f1", "interHash" : "799d650ca4ed266c0d7599b1498e42d2", "label" : "Designing Regular and Irregular Elastic Gridshells by Six DOF Dynamic Relaxation", "user" : "itke", "description" : "", "date" : "2020-05-22 14:28:48", "changeDate" : "2020-05-22 12:28:48", "count" : 2, "pub-type": "inproceedings", "booktitle": "Rethinking Prototyping: Proceedings of the Design Modelling Symposium Berlin 2013","publisher":"Universität der Künste","address":"Berlin", "year": "2013", "url": "", "author": [ "Jian-Min Li","Jan Knippers" ], "authors": [ {"first" : "Jian-Min", "last" : "Li"}, {"first" : "Jan", "last" : "Knippers"} ], "editor": [ "Christoph Gengnagel","Axel Kilian","Julien Nembrini","Fabian Scheurer" ], "editors": [ {"first" : "Christoph", "last" : "Gengnagel"}, {"first" : "Axel", "last" : "Kilian"}, {"first" : "Julien", "last" : "Nembrini"}, {"first" : "Fabian", "last" : "Scheurer"} ], "pages": "31 -44", "isbn" : "9783894622435", "language" : "eng", "bibtexKey": "li2013designing" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/21f29aada1b2d2ca56eddae85465f7dfd/itke", "tags" : [ "2001","bulenda","from:petraheim","gitterschale","grid","itke","knippers","peer-reviewed","shell" ], "intraHash" : "1f29aada1b2d2ca56eddae85465f7dfd", "interHash" : "bd3729242eaeae4aae7608bb245369a0", "label" : "Stability of grid shells", "user" : "itke", "description" : "", "date" : "2020-05-22 14:27:37", "changeDate" : "2020-07-01 15:01:39", "count" : 2, "pub-type": "article", "journal": "Computers and Structures", "year": "2001", "url": "", "author": [ "Thomas Bulenda","Jan Knippers" ], "authors": [ {"first" : "Thomas", "last" : "Bulenda"}, {"first" : "Jan", "last" : "Knippers"} ], "editor": [ " elsevier" ], "editors": [ {"first" : "", "last" : "elsevier"} ], "volume": "79","pages": "1161 \u2013 1174","abstract": "Grid shells exhibit different modes of stability failure. This paper explains some parameters influencing the failure load of domes and barrel vaults and makes suggestions for the imperfection shape which has to be assumed in an analysis. All computations are carried out with a commercial FE-program.", "language" : "eng", "bibtexKey": "bulenda2001stability" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2a4ae2d8aaf070aa1b9f3e6ca5de9e4f0/itke", "tags" : [ "development","glass","helbig","knippers","shell","peer-reviewed","2009","design","grid","from:petraheim","architecture","glazed" ], "intraHash" : "a4ae2d8aaf070aa1b9f3e6ca5de9e4f0", "interHash" : "9e73c6954498dac578e7a102e5ca9570", "label" : "Recent Developments in the Design of Glazed Grid Shells", "user" : "itke", "description" : "", "date" : "2020-05-22 14:26:47", "changeDate" : "2020-05-22 12:26:47", "count" : 2, "pub-type": "article", "journal": "International Journal of Space Structures", "year": "2009", "url": "", "author": [ "Jan Knippers","Thorsten Helbig" ], "authors": [ {"first" : "Jan", "last" : "Knippers"}, {"first" : "Thorsten", "last" : "Helbig"} ], "editor": [ "Sage Publishing" ], "editors": [ {"first" : "Sage", "last" : "Publishing"} ], "volume": "24","number": "2","pages": "111 \u2013 126", "language" : "eng", "bibtexKey": "knippers2009recent" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f340b0eeb9ab4fbdd5762bca9bc93f4f/itke", "tags" : [ "2009","buckling","connection","connector","engineering","from:petraheim","grid","hwang","influence","itke","knippers","load","node","park","shell","types","various" ], "intraHash" : "f340b0eeb9ab4fbdd5762bca9bc93f4f", "interHash" : "ff5cbf22dad48b90dd293c5634b5f2cc", "label" : "Influence of various types of node connectors on the buckling loads of grid shells", "user" : "itke", "description" : "", "date" : "2020-05-22 14:24:43", "changeDate" : "2021-07-09 09:04:24", "count" : 2, "pub-type": "inproceedings", "booktitle": "Evolution and Trends in Design, Analysis and Construction of Shell ans Spatial Structures, IASS Symposium","address":"Valencia, Spain", "year": "2009", "url": "", "author": [ "Kyung-Ju Hwang","Jan Knippers","Sun-Woo Park" ], "authors": [ {"first" : "Kyung-Ju", "last" : "Hwang"}, {"first" : "Jan", "last" : "Knippers"}, {"first" : "Sun-Woo", "last" : "Park"} ], "pages": "426 \u2013 427", "language" : "eng", "bibtexKey": "hwang2009influence" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f95536bda701d0d91f57d570bbe7552b/itke", "tags" : [ "2007","architecture","from:petraheim","grid","helbig","knippers","shape","shell","smooth","stable" ], "intraHash" : "f95536bda701d0d91f57d570bbe7552b", "interHash" : "ee711b0855a246d1278977edc5ca50d7", "label" : "Smooth shapes and stable grids", "user" : "itke", "description" : "", "date" : "2020-05-22 14:24:43", "changeDate" : "2021-07-09 09:04:03", "count" : 2, "pub-type": "inproceedings", "booktitle": "IASS Symposium Shell and Spatial Structures: Structural Architecture \u2013 Towards the future looking to the past","address":"Venice, Italy", "year": "2007", "url": "", "author": [ "Jan Knippers","Thorsten Helbig" ], "authors": [ {"first" : "Jan", "last" : "Knippers"}, {"first" : "Thorsten", "last" : "Helbig"} ], "pages": "207 \u2013 208", "language" : "eng", "bibtexKey": "knippers2007smooth" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2693d16d8837d39db0a77f242011fd2d1/itke", "tags" : [ "2009","architecture","dach","engineering","frankfurt","from:petraheim","glas","glasdach","grid","helbig","itke","knippers","shell","zeil" ], "intraHash" : "693d16d8837d39db0a77f242011fd2d1", "interHash" : "635e91172bc4d6c8ab6ed68263245485", "label" : "The Frankfurt Zeil Grid Shell", "user" : "itke", "description" : "", "date" : "2020-05-22 14:24:19", "changeDate" : "2021-07-09 09:08:28", "count" : 2, "pub-type": "inproceedings", "booktitle": "Evolution and Trends in Design, Analysis and Construction of Shell ans Spatial Structures, IASS Symposium","address":"Valencia, Spain", "year": "2009", "url": "", "author": [ "Jan Knippers","Thorsten Helbig" ], "authors": [ {"first" : "Jan", "last" : "Knippers"}, {"first" : "Thorsten", "last" : "Helbig"} ], "pages": "328 \u2013 329", "language" : "eng", "bibtexKey": "knippers2009frankfurt" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/27526433110417bc07ec9885fb40e2b80/itke", "tags" : [ "grid","itke","from:petraheim","continuous","rod","elastic","2011","engineering","shell","form-finding" ], "intraHash" : "7526433110417bc07ec9885fb40e2b80", "interHash" : "79920e7440b9243ba1e25b4797c8e869", "label" : "Form-finding of grid shells with continuous elastic rods", "user" : "itke", "description" : "", "date" : "2020-05-22 14:24:19", "changeDate" : "2020-05-22 12:24:19", "count" : 2, "pub-type": "inproceedings", "booktitle": "Proceedings of the International Symposium of the IABSE-IASS Symposium","address":"London, UK", "year": "2011", "url": "", "author": [ "Jian-Min Li","Jan Knippers" ], "authors": [ {"first" : "Jian-Min", "last" : "Li"}, {"first" : "Jan", "last" : "Knippers"} ], "language" : "eng", "bibtexKey": "li2011formfinding" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2946c9bbd52a2286eee41919fe871dd04/itke", "tags" : [ "initial","modeling","bonavia","körner","method","vecvagare","knippers","shell","modelling","gridshell","point","2019","design","grid","itke","from:petraheim","load","wood","architecture","actuated" ], "intraHash" : "946c9bbd52a2286eee41919fe871dd04", "interHash" : "261193b0887bc4dca8cd387a63061a0e", "label" : "Point load Actuated Adaptive Gridshells: Methods for initial design and modeling", "user" : "itke", "description" : "", "date" : "2020-05-22 14:22:38", "changeDate" : "2020-05-22 12:22:38", "count" : 3, "pub-type": "inproceedings", "booktitle": "Proceedings of IASS Annual Symposium 2019 \u2013 Structural Membranes 2019 Form and Force","address":"Barcelona, Spain", "year": "2019", "url": "", "author": [ "Elaine Bonavia","S. Vecvagare","Axel Körner","Dylan Wood","Jan Knippers" ], "authors": [ {"first" : "Elaine", "last" : "Bonavia"}, {"first" : "S.", "last" : "Vecvagare"}, {"first" : "Axel", "last" : "Körner"}, {"first" : "Dylan", "last" : "Wood"}, {"first" : "Jan", "last" : "Knippers"} ], "language" : "eng", "bibtexKey": "bonavia2019point" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/29fa32fdbc6429900820d9a550952ad85/itke", "tags" : [ "2010","advanced","diss","dissertation","engineering","forschungsbericht","from:petraheim","grid","hwang","investigation","itke","shell","spatial","structure" ], "intraHash" : "9fa32fdbc6429900820d9a550952ad85", "interHash" : "d0b08347c5da29bf15f973866384be2f", "label" : "Advanced Investigations of Grid Spatial Structures", "user" : "itke", "description" : "", "date" : "2020-05-22 14:20:04", "changeDate" : "2020-06-24 12:06:35", "count" : 2, "pub-type": "phdthesis", "series": "Forschungsberichte aus dem Institut für Tragkonstruktionen und Konstruktives Entwerfen","publisher":"Stuttgart: Institut für Tragkonstruktionen und Konstruktives Entwerfen","address":"ITKE, Stuttgart, Germany", "year": "2010", "url": "", "author": [ "Kyung-Ju Hwang" ], "authors": [ {"first" : "Kyung-Ju", "last" : "Hwang"} ], "editor": [ "Jan Knippers" ], "editors": [ {"first" : "Jan", "last" : "Knippers"} ], "volume": "31","abstract": "Free-form grid spatial structures and facades that follow the envelope surface of a complex-shaped skin, such as the DZ-Bank in Berlin (Frank 0. Gehry), the British Museum in London (Norman Foster), the My Zeil in Frankfurt (Massimiliano Fuksas), have become a very interesting issue in modern architecture. There are several important factors in such single layer lattice dome and complex-shaped spatial structures, for instance, optimal form finding and strong material strength and so forth, but the optimal design and analysis of connection are significant points in free-form spatial structures, because such extraordinary geometries and its continuously changing curvature can be defined by the angles of the connections' geometries, and the stiffness of connection can determine the stability of the whole free-form structure. Therefore, it is very important to recognize that the appropriate analysis and connection design have to be performed, in order to design the reasonable global single layer spatial structure and free-form spatial structures.\r\nGeneral procedures\r\nFor the FEA of four connection systems, bending stiffness (My and Mz) and axial force (F) tests were performed. These analyses include the modeling of the bolt assembly, the contact stiffness and the influence of bolt clearances, which were considered using two parameters, such that D..V=0.1 mm and 2.0mm. Due to a specific function of COMBIN39 in ANSYS, the moment-rotation behaviors and load-displacement curves could be transferred to nonlinear spring elements in global grid shells with 25 m and 50 m span that have three different rise-span ratios (0.1, 0.2 and 0.3), to realize the non linear characteristics of the connection systems.\r\n\r\nResults\r\nConnection system having two shear planes showed higher stiffness than those with one shear plane. On the other hand, node connectors with one shear plane were not as influenced by differing bolt-holes as those with two shear planes due to shape-of-joint behaviour. Secondly, the low connection stiffness with initial geometrical imperfection easily leads membrane stress to bending stress, so that the critical point of the grid shell occurred with low load failure factor. The influence of bolt clearance depends mainly on the node stiffness and rise-span ratio. The overall structural behavior of an imperfect high-rise grid shell can be very sensitive, displaying a large deviation of bending stiffness due to bolt clearances.", "isbn" : "978-3-922302-31-5", "language" : "eng", "bibtexKey": "hwang2010advanced" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/226f1ec9390a0245dacb4b4e464bbec11/itke", "tags" : [ "2017","acttively","analysis","bent","diss","dissertation","engineering","form-finding","forschungsbericht","from:petraheim","grid","itke","li","plate","segmental","shell","structural","structure","timber" ], "intraHash" : "26f1ec9390a0245dacb4b4e464bbec11", "interHash" : "b63b7f1729a68f2d49cf78422af4e9de", "label" : "Timber Shell Structures: Form-finding and Structural Analysis of Actively Bent Grid Shells and Segmental Plate Shells", "user" : "itke", "description" : "", "date" : "2020-05-22 14:20:04", "changeDate" : "2020-06-23 14:37:36", "count" : 2, "pub-type": "phdthesis", "series": "Forschungsberichte aus dem Institut für Tragkonstruktionen und Konstruktives Entwerfen","publisher":"Stuttgart: Institut für Tragkonstruktionen und Konstruktives Entwerfen","address":"ITKE, Stuttgart, Germany", "year": "2017", "url": "", "author": [ "Li. Jian-Min" ], "authors": [ {"first" : "Li.", "last" : "Jian-Min"} ], "editor": [ "Jan Knippers" ], "editors": [ {"first" : "Jan", "last" : "Knippers"} ], "volume": "42","abstract": "Shell structures are structurally efficient but difficult to manufacture and thus expansive. Actively bent grid shells and segmental plate shells could be alternatives. The first kind utilizes bended members to form a continuously curved geometry and thus reduce the complexity of the joints. The second kind utilizes the stability inherited in trivalent geometries to be able to build a shell without using bending stiff joints. Both these two types of timber shell structures could largely reduce the construction cost. That is why they are chosen as the research topics. The dynamic relaxation method (DR) is applied in this research as an important numerical method. It is used as the fundamental base for developing the form-finding tools of both actively bent grid shells\r\nand the segmental grid shells. A solver capable of the structural analysis of beam system is also developed here based on DR. Through the text, we show that DR could handle not only form-finding problems but also geometrically nonlinear analysis.\r\nThe dissertation consists of four parts. Part I is the introduction. Part II and Part III present both the form-finding and analysis techniques of these two types of timber shell structures. The last part is the conclusions.", "isbn" : "978-3-922302-42-1", "language" : "eng", "bibtexKey": "jianmin2017timber" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/24227971b3516b084125d1b37e8dcbac0/itke", "tags" : [ "2012","algorithm","architecture","based","dimcic","diss","dissertation","engineering","forschungsbericht","from:petraheim","genetic","grid","itke","optimisation","optimization","shell","structural" ], "intraHash" : "4227971b3516b084125d1b37e8dcbac0", "interHash" : "62f2af1051cae336f6d6ec10e72fed49", "label" : "Structural Optimization of Grid Shells based on Genetic Algorithms", "user" : "itke", "description" : "", "date" : "2020-05-22 14:20:03", "changeDate" : "2020-06-24 11:41:45", "count" : 2, "pub-type": "phdthesis", "series": "Forschungsberichte aus dem Institut für Tragkonstruktionen und Konstruktives Entwerfen","publisher":"Stuttgart: Institut für Tragkonstruktionen und Konstruktives Entwerfen","address":"ITKE, Stuttgart, Germany", "year": "2012", "url": "", "author": [ "Milos Dimcic" ], "authors": [ {"first" : "Milos", "last" : "Dimcic"} ], "editor": [ "Jan Knippers" ], "editors": [ {"first" : "Jan", "last" : "Knippers"} ], "volume": "32","abstract": "In the 21st century, as free form design gains popularity, free-form grid shells are becoming a universal structural solution, enabling merger of structure and facade into a single layer - a skin [31]. The subject of the presented work is the optimization of grid structures over some predefined free form shape, with the goal of generating\r\na stable and statically efficient structure. It is shown how combining design and FEM software in an iterative, Genetic Algorithms based, optimization process, stress and displacements in grid shell structures can be significantly reduced, whereby material can be saved and stability enhanced.\r\nWithin this research, design and static analysis software are combined in order to perform a statical optimization of grid shells,generated over a given free form surface. A plug-in for Rhinoceros 3D (software based on NURBS [44] geometry representation) is developed, that uses Genetic Algorithms as an optimization method and implements automated iterative calls to Oasys GSA (commercial FEM static analysis software) in order to generate a statically optimal grid shell. To make this possible, within this research some new types of automatic grid generation are developed. Voronoi\r\ndiagrams [11] were used together with the adapted Force-Density method [38] to develop a new type of grid structure that we called Voronax. In the presented work it was shown that, using the same free form surface, and using the same number of joints and structural members, we can generate much more efficient grid shells,\r\nwhen compared to the standard (uniform) grid structures, simply by modifying the structural grid, i.e., rearranging the structural members of the grid shell.\r\nThe work presented offers an explanation of the entire method and how it can be constructed. The results of the experiments are there to prove its efficiency and credibility. Once it is proved that the method works, its application can take various forms and be left to the creativity of the user and the requirements of the\r\nspecific project.", "isbn" : "978-3-922302-32-2", "language" : "eng", "bibtexKey": "dimcic2012structural" } ] }