{ "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/2120e2f721e7979c655fd2871b9933053/itke", "tags" : [ "Wild","biodiversity","Bio-Integrated","Rojas","Knippers","Bees","Geometry-Driven","Urban","Design","Additive","itke","2025","Manufacturing","Regulation","Valverde","Habitat","Österreicher","Thermal" ], "intraHash" : "120e2f721e7979c655fd2871b9933053", "interHash" : "fabbbfd2447a1f88b9560829e3b98af0", "label" : "Rethinking Urban Surfaces: Geometry-Driven Thermal Solutions for Wild Bee Habitats", "user" : "itke", "description" : "", "date" : "2026-02-26 16:45:35", "changeDate" : "2026-02-26 16:45:35", "count" : 2, "pub-type": "proceedings", "booktitle": "Research Directions: Biotechnology Design","publisher":"Cambridge University Press", "year": "2025", "url": "", "author": [ "Maria Claudia Valverde Rojas","Doris Österreicher","Jan Kniüüers" ], "authors": [ {"first" : "Maria Claudia", "last" : "Valverde Rojas"}, {"first" : "Doris", "last" : "Österreicher"}, {"first" : "Jan", "last" : "Kniüüers"} ], "abstract": "Urban surfaces, far from being static architectural elements, actively mediate ecological and climatic processes in urban environments (Meggers, 2015; Barry and Blanken, 2016; Yang et al., 2023). This study is part of an ongoing Ph.D. project at the Cluster of Excellence Integrative Computational Design and Construction for Architecture (IntCDC), University of Stuttgart, investigating geometry-driven thermal regulation in bio-integrated urban surfaces. \r\nIt contributes to a broader exploration of additive manufacturing and porous structures for enhancing urban biodiversity, particularly for wild bee conservation. Using wild bee nesting as a focal case study, it addresses the regulation of temperature within nests to mitigate the detrimental effects of elevated temperatures, including developmental delays, metabolic stress, and offspring mortality (Radmacher and Strohm, 2010; Hamblin et al., 2017; Maebe et al., 2021; Vilchez-Russell and Rafferty, 2024). As primary pollinators, wild bees are indispensable to biodiversity and urban ecosystem functioning (Lowenstein et al., 2015; Winfree et al., 2011). They enhance green infrastructure by supporting plant reproductive success, contributing to urban \r\nresilience and ecological balance (Kammerer et al., 2021; Ferrari and Polidori, 2022).\r\nUrban surfaces present a valuable opportunity to create continuous networks of nesting and foraging resources, promoting ecological connectivity within the built environment (Radfar, 2012; Cruz, 2016; Bornschlegl et al., 2023; Prieto and Pastén, 2024). By serving as permeable interfaces, these surfaces can facilitate species movement, provide access to various resources, and help maintain the genetic \r\ndiversity necessary for adapting to environmental changes, such as climate change (Everaars et al., 2011; Scheffers et al., 2016; Zölch et al., 2016). Given the limited dispersal abilities of solitary bees, a continuous network of resources in urban areas can play an important role in their conservation (MacIvor and Packer, 2015; Ostap-Chec et al., 2021, Polidori et al., 2023). This study explores geometry-driven strategies to address microclimatic challenges, employing porous cellular structures for their thermodynamic properties and potential to support various species, from pollinators to microfauna. Additive manufacturing was chosen to fabricate these complex, adaptive geometries. 3D-printed samples were tested alongside one traditional nesting aid on a southeast-facing facade in Stuttgart, Germany, in August 2024 (see Figure 1). While the 3D-printed designs demonstrated moderate thermal benefits, their value lies in reimagining urban surfaces as components for fostering ecological resilience. Innovation and speculative approaches are central for addressing contemporary ecological challenges, which are increasingly defined by legal frameworks and policy directives (Federal Ministry for the Environment, 2010; Federal Parliament of Germany, 2020).\r\nThis work examines the role of the more-than-human approach in the built environment. It presents urban surfaces as potential adaptive and multifunctional systems that could actively promote biodiversity and ecological connectivity. This perspective sets the stage for future improvements in the experiments.", "language" : "eng", "bibtexKey": "valverderojas2025rethinking" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/254d3a4a5bf50555dbaa5de703d3440b2/itke", "tags" : [ "Structures","Structural","magna","knippers","2022","Transformable","framework","Spatial","itke","material","from:petraheim","klammer","Bending-Active","rihaczek","Aided","Free-Form","curved","basnak","Retractable","körner","Digital","Deployable","Timber","Optimization","origami","Design","Additive","Manufacturing","Computer" ], "intraHash" : "54d3a4a5bf50555dbaa5de703d3440b2", "interHash" : "51fb2bb419d32836b7625da9849f5a00", "label" : "Timbr Foldr \u2013 A Design Framework and Material System for Closed Cross - Section Curved Folded Structures", "user" : "itke", "description" : "", "date" : "2023-01-17 13:24:46", "changeDate" : "2023-01-17 12:24:46", "count" : 2, "pub-type": "article", "journal": "Journal of the International Association for Shell and Spatial Structures","publisher":"International Association for Shell and Spatial Structures (IASS)","address":"Alfonso XII, 3; 28014 Madrid, Spain", "year": "2022", "url": "", "author": [ "Gabriel Rihaczek","Maximilian Klammer","Okan Basnak","Axel Köerner","Riccardo La Magna","Jan Knippers" ], "authors": [ {"first" : "Gabriel", "last" : "Rihaczek"}, {"first" : "Maximilian", "last" : "Klammer"}, {"first" : "Okan", "last" : "Basnak"}, {"first" : "Axel", "last" : "Köerner"}, {"first" : "Riccardo", "last" : "La Magna"}, {"first" : "Jan", "last" : "Knippers"} ], "volume": "63","number": "4","pages": "272 - 288","abstract": "This research investigated building components that can be produced and transported in a flat state and transformed to a spatial state without scaffolding on-site. Curved folding was employed to allow for a shape change between flat and spatial bending active structures. Bending generally allows for expressive curvature with simple flat production as well as easy customization. Limitations presented by laborious forming and upscaling of individually bent plates were overcome by large-scale curved folding.\r\nThe present research builds upon the context but adds a design framework for volumetric curved folded components, a bistable behavior, and comprehensive detailing regarding upscaling and increased structural capacity. The mechanism was studied on a kinematic level, considering geometrical rules of curved folding and\r\nthe design space. It was also studied on a kinetic level under the consideration of material properties specific to plywood. As a proof of concept, a 1:1 scale demonstrator was built. Finite element modeling software was used to optimize\r\nthe shape. The demonstrator was fabricated flat, folded up, and locked in its stable configuration by the bistability and bases. It supported twelve people with a self-weight of approximately 300kg.", "language" : "eng", "issn" : "1028-365X", "doi" : "https://doi.org/10.20898/j.iass.2022.014", "bibtexKey": "rihaczek2022timbr" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/24335399871971072a954e6879dfff2ac/itke", "tags" : [ "2014","architecture","composite","from:petraheim","itke","körner","manufacturing","plywood","stiffness","structure","subtractive","variable","variable-stiffness" ], "intraHash" : "4335399871971072a954e6879dfff2ac", "interHash" : "ca2dbd6027f73a90e5149acc2b980579", "label" : "Subtractive Manufacturing for Variable-Stiffness Plywood Composite Structures", "user" : "itke", "description" : "", "date" : "2020-05-22 14:50:36", "changeDate" : "2021-07-08 14:45:17", "count" : 2, "pub-type": "inproceedings", "booktitle": "Proceedings of the SDM 2014, Internat. Conference on Sustainable Design & Manufacturing","address":"Cardiff, Wales, UK", "year": "2014", "url": "", "author": [ "Axel Körner" ], "authors": [ {"first" : "Axel", "last" : "Körner"} ], "editor": [ "R. Setchi","R.J. Howlett","M. Naim","H. Seinz" ], "editors": [ {"first" : "R.", "last" : "Setchi"}, {"first" : "R.J.", "last" : "Howlett"}, {"first" : "M.", "last" : "Naim"}, {"first" : "H.", "last" : "Seinz"} ], "pages": "50 \u2013 66", "language" : "eng", "bibtexKey": "korner2014subtractive" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/21545f76af0c913423727e77ac222a4ee/itke", "tags" : [ "2020","aldinger","bechert","burgert","clt","curved","from:petraheim","gartenschau","itke","knippers","lehmann","manufacturing","menges","remstal","riggenbach","ruggeberg","self-shaping","structure","timber","tower","urbach","wood" ], "intraHash" : "1545f76af0c913423727e77ac222a4ee", "interHash" : "393f656ee738785173e0056341845792", "label" : "From Machine Control to Material Programming Self-Shaping Wood Manufacturing of a High Performance Curved CLT Structure - Urbach Tower", "user" : "itke", "description" : "", "date" : "2020-05-22 14:29:51", "changeDate" : "2021-07-08 14:47:02", "count" : 3, "pub-type": "inbook", "journal": "Making Resilent Architecture - FABRICATE 2020", "year": "2020", "url": "", "author": [ "Dylan Wood","Philippe Grönquist","Simon Bechert","Lotte Aldinger","David Riggenbach","Katharina Lehmann","Markus Rüggeberg","Ingo Burgert","Jan Knippers","Achim Menges" ], "authors": [ {"first" : "Dylan", "last" : "Wood"}, {"first" : "Philippe", "last" : "Grönquist"}, {"first" : "Simon", "last" : "Bechert"}, {"first" : "Lotte", "last" : "Aldinger"}, {"first" : "David", "last" : "Riggenbach"}, {"first" : "Katharina", "last" : "Lehmann"}, {"first" : "Markus", "last" : "Rüggeberg"}, {"first" : "Ingo", "last" : "Burgert"}, {"first" : "Jan", "last" : "Knippers"}, {"first" : "Achim", "last" : "Menges"} ], "volume": "4", "file" : "5d713e87-5e45-4e97-8bf7-b2cb9ed40033:C\\:\\\\Users\\\\dylan\\\\AppData\\Łocal\\\\Swiss Academic Software\\\\Citavi 6\\\\ProjectCache\\\\u3csa2woffyfce3k2opd1sxqbtzxrhjbzb3mgh51uvfz2c6pjlh\\\\Citavi Attachments\\\\5d713e87-5e45-4e97-8bf7-b2cb9ed40033.docx:docx", "isbn" : "9781787358119", "doi" : "https://www.uclpress.co.uk/products/154646", "bibtexKey": "Wood.2020" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/298c04840dc9d7801ab919b2eae3ccef6/itke", "tags" : [ "2015","cfrp","cheng","concrete","connector","design","formwork","from:petraheim","gabler","hasselhoff","itke","knippers","manufacturing","peer-reviewed","shear-cone","stay-in-place","testing","waimer" ], "intraHash" : "98c04840dc9d7801ab919b2eae3ccef6", "interHash" : "484e1e67db321ff8ed31ae4583eda42d", "label" : "Design, manufacturing and testing of shear-cone connectors between CFRP stay-in-place formwork and concrete", "user" : "itke", "description" : "", "date" : "2020-05-22 14:25:35", "changeDate" : "2020-06-29 12:33:10", "count" : 3, "pub-type": "article", "journal": "COMPOSITE STRUCTURES","publisher":"ELSEVIER SCI LTD", "year": "2015", "url": "", "author": [ "Johannes Hasselhoff","Lijuan Cheng","Frederic Waimer","Markus Gabler","Jan Knippers" ], "authors": [ {"first" : "Johannes", "last" : "Hasselhoff"}, {"first" : "Lijuan", "last" : "Cheng"}, {"first" : "Frederic", "last" : "Waimer"}, {"first" : "Markus", "last" : "Gabler"}, {"first" : "Jan", "last" : "Knippers"} ], "volume": "129","pages": "47-54","abstract": "Stay-in-place formwork is often used to accelerate the construction of structural elements such as flooring, concrete bridge decks and compressed shells. This study aims at designing, manufacturing and testing of two different nonlinear shear connectors made of fiber reinforced polymer composites for the formwork: (1) non-directional, cylindrical shear-cones; and (2) directional, cubical shear-cones with one side beveled. Six 1m-long specimens were constructed using carbon fiber reinforced polymer stay-in-place formwork and a plain concrete slab (200 wide and 130mm thick). Based on the results of three-point bending tests, similar stiffness, load\u2013displacement response and failure mode were observed in the two contrasting designs. The resistance of the specimens using cylindrical shear-cones was approximately 26% higher than that of the ones with cubical design.", "research-areas" : "Materials Science", "eissn" : "1879-1085", "language" : "English", "issn" : "0263-8223", "affiliation" : "Cheng, LJ (Reprint Author), Univ Calif Davis, Dept Civil & Environm Engn, One Shields Ave, Davis, CA 95616 USA.\r\n Hasselhoff, Johannes; Waimer, Frederic; Knippers, Jan, Univ Stuttgart, ITKE, Inst Bldg Struct & Struct Design, D-70174 Stuttgart, Germany.\r\n Cheng, Lijuan, Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA.\r\n Gabler, Markus, Buckland & Taylor Ltd, N Vancouver, BC V7P 3R7, Canada.", "unique-id" : "ISI:000355883200005", "doi" : "10.1016/j.compstruct.2015.04.001", "bibtexKey": "hasselhoff2015design" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/240feb8991aa85da825e7b99138c37774/itke", "tags" : [ "concrete","Hehl","siebert","born","fibre-reinforced","gresser","knippers","plastic","hausmann","structure","2018","jonas","hybrid","itke","from:petraheim","composite","möhl","manufacturing","branched" ], "intraHash" : "40feb8991aa85da825e7b99138c37774", "interHash" : "0e7bc2bcc756535a1dfc7616dd59a093", "label" : "Manufacturing of branched structures for fibre-reinforced plastic-concrete-hybrid composites", "user" : "itke", "description" : "", "date" : "2020-05-22 14:23:01", "changeDate" : "2020-05-22 12:23:01", "count" : 3, "pub-type": "inproceedings", "booktitle": "Hybrid 2018 in Bremen", "year": "2018", "url": "", "author": [ "C. Möhl","L. Born","Florian Alexander Jonas","Götz T. Gresser","Jan Knippers","J.M. Hausmann","M. Siebert","A. von Hehl" ], "authors": [ {"first" : "C.", "last" : "Möhl"}, {"first" : "L.", "last" : "Born"}, {"first" : "Florian Alexander", "last" : "Jonas"}, {"first" : "Götz T.", "last" : "Gresser"}, {"first" : "Jan", "last" : "Knippers"}, {"first" : "J.M.", "last" : "Hausmann"}, {"first" : "M.", "last" : "Siebert"}, {"first" : "A.", "last" : "von Hehl"} ], "pages": "pp 165-170.","abstract": "In modern architecture branched supporting structures are increasingly used. Until now,\r\nthese branched columns can only be produced in an extensive and cost-intensive way. A new concept made of fibre-reinforced plastic (FRP) serving as a formwork and a load-bearing hull for a concrete core makes it possible to produce a wide variety of different forms and geometries. To enable the potential of complex branched geometries, especially continuous load-confirming fibre arrangements over the entire braiding hull\r\nand large diameters, an advanced braiding technique to create triaxially braided preforms is required. This paper focuses on recent developments of an advanced braiding process to fabricate a multi-layered complex structural geometry on a 144 bobbins radial braiding machine and the adaptation of stationary threads until now regulated by spring force into ones operated electronically. With the new braiding technique, branched performs with triaxial braids were produced. Subsequent to impregnation with a thermosetting resin and annealing, the FRP-hull is poured with concrete. To evaluate a potential load increase of load capacity of the concrete core due to the confinement of FRP-hulls compression\r\ntests are conducted. In comparison to plain concrete specimens the mechanical parameters of fibrereinforced plastic-concrete-composites show a significant increase in compression strength.", "language" : "eng", "bibtexKey": "c2018manufacturing" } ] }