[{"date_updated":"2024-01-29T10:47:51Z","oa":1,"article_processing_charge":"No","user_id":"400429CC-F248-11E8-B48F-1D18A9856A87","project":[{"grant_number":"715767","call_identifier":"H2020","name":"MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and Modeling","_id":"24F9549A-B435-11E9-9278-68D0E5697425"}],"oa_version":"Published Version","_id":"12897","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-031-2"]},"publication_status":"published","citation":{"apa":"Hafner, C. (2023). <i>Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:12897\">https://doi.org/10.15479/at:ista:12897</a>","ieee":"C. Hafner, “Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models,” Institute of Science and Technology Austria, 2023.","chicago":"Hafner, Christian. “Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models.” Institute of Science and Technology Austria, 2023. <a href=\"https://doi.org/10.15479/at:ista:12897\">https://doi.org/10.15479/at:ista:12897</a>.","ama":"Hafner C. Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models. 2023. doi:<a href=\"https://doi.org/10.15479/at:ista:12897\">10.15479/at:ista:12897</a>","mla":"Hafner, Christian. <i>Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models</i>. Institute of Science and Technology Austria, 2023, doi:<a href=\"https://doi.org/10.15479/at:ista:12897\">10.15479/at:ista:12897</a>.","ista":"Hafner C. 2023. Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models. Institute of Science and Technology Austria.","short":"C. Hafner, Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models, Institute of Science and Technology Austria, 2023."},"author":[{"last_name":"Hafner","full_name":"Hafner, Christian","first_name":"Christian","id":"400429CC-F248-11E8-B48F-1D18A9856A87"}],"abstract":[{"lang":"eng","text":"Inverse design problems in fabrication-aware shape optimization are typically solved on discrete representations such as polygonal meshes. This thesis argues that there are benefits to treating these problems in the same domain as human designers, namely, the parametric one. One reason is that discretizing a parametric model usually removes the capability of making further manual changes to the design, because the human intent is captured by the shape parameters. Beyond this, knowledge about a design problem can sometimes reveal a structure that is present in a smooth representation, but is fundamentally altered by discretizing. In this case, working in the parametric domain may even simplify the optimization task. We present two lines of research that explore both of these aspects of fabrication-aware shape optimization on parametric representations.\r\n\r\nThe first project studies the design of plane elastic curves and Kirchhoff rods, which are common mathematical models for describing the deformation of thin elastic rods such as beams, ribbons, cables, and hair. Our main contribution is a characterization of all curved shapes that can be attained by bending and twisting elastic rods having a stiffness that is allowed to vary across the length. Elements like these can be manufactured using digital fabrication devices such as 3d printers and digital cutters, and have applications in free-form architecture and soft robotics.\r\n\r\nWe show that the family of curved shapes that can be produced this way admits geometric description that is concise and computationally convenient. In the case of plane curves, the geometric description is intuitive enough to allow a designer to determine whether a curved shape is physically achievable by visual inspection alone. We also present shape optimization algorithms that convert a user-defined curve in the plane or in three dimensions into the geometry of an elastic rod that will naturally deform to follow this curve when its endpoints are attached to a support structure. Implemented in an interactive software design tool, the rod geometry is generated in real time as the user edits a curve and enables fast prototyping. \r\n\r\nThe second project tackles the problem of general-purpose shape optimization on CAD models using a novel variant of the extended finite element method (XFEM). Our goal is the decoupling between the simulation mesh and the CAD model, so no geometry-dependent meshing or remeshing needs to be performed when the CAD parameters change during optimization. This is achieved by discretizing the embedding space of the CAD model, and using a new high-accuracy numerical integration method to enable XFEM on free-form elements bounded by the parametric surface patches of the model. Our simulation is differentiable from the CAD parameters to the simulation output, which enables us to use off-the-shelf gradient-based optimization procedures. The result is a method that fits seamlessly into the CAD workflow because it works on the same representation as the designer, enabling the alternation of manual editing and fabrication-aware optimization at will."}],"alternative_title":["ISTA Thesis"],"ddc":["516","004","518","531"],"related_material":{"record":[{"status":"public","id":"9817","relation":"part_of_dissertation"},{"status":"public","relation":"part_of_dissertation","id":"7117"},{"id":"13188","relation":"dissertation_contains","status":"public"}]},"ec_funded":1,"acknowledged_ssus":[{"_id":"M-Shop"}],"year":"2023","doi":"10.15479/at:ista:12897","title":"Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models","file_date_updated":"2023-12-08T23:30:04Z","page":"180","type":"dissertation","day":"05","status":"public","supervisor":[{"id":"49876194-F248-11E8-B48F-1D18A9856A87","first_name":"Bernd","orcid":"0000-0001-6511-9385","last_name":"Bickel","full_name":"Bickel, Bernd"}],"department":[{"_id":"GradSch"},{"_id":"BeBi"}],"degree_awarded":"PhD","has_accepted_license":"1","date_created":"2023-05-05T10:40:14Z","file":[{"creator":"chafner","file_id":"12942","relation":"main_file","content_type":"application/pdf","access_level":"open_access","date_updated":"2023-12-08T23:30:04Z","checksum":"cc2094e92fa27000b70eb4bfb76d6b5a","date_created":"2023-05-11T10:43:20Z","file_size":50714445,"embargo":"2023-12-07","file_name":"thesis-hafner-2023may11-a2b.pdf"},{"access_level":"closed","date_updated":"2023-12-08T23:30:04Z","embargo_to":"open_access","checksum":"a6b51334be2b81672357b1549afab40c","date_created":"2023-05-11T10:43:44Z","file_size":265319,"file_name":"thesis-release-form.pdf","file_id":"12943","creator":"chafner","relation":"source_file","content_type":"application/pdf"}],"date_published":"2023-05-05T00:00:00Z","month":"05","language":[{"iso":"eng"}],"publisher":"Institute of Science and Technology Austria"},{"oa_version":"Published Version","project":[{"grant_number":"715767","call_identifier":"H2020","_id":"24F9549A-B435-11E9-9278-68D0E5697425","name":"MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and Modeling"}],"acknowledgement":"During the work on this thesis, I received substantial support from IST Austria’s scientific service units. A big thank you to Todor Asenov and other Miba Machine Shop team members for their help with fabrication of experimental prototypes. In addition, I would like to thank Scientific Computing team for the support with high performance computing.\r\nFinancial support was provided by the European Research Council (ERC) under grant agreement No 715767 - MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and Modeling, which I gratefully acknowledge.","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-010-7"]},"_id":"8366","article_processing_charge":"No","oa":1,"date_updated":"2024-02-21T12:44:29Z","author":[{"id":"3AB45EE2-F248-11E8-B48F-1D18A9856A87","full_name":"Guseinov, Ruslan","last_name":"Guseinov","orcid":"0000-0001-9819-5077","first_name":"Ruslan"}],"keyword":["computer-aided design","shape modeling","self-morphing","mechanical engineering"],"abstract":[{"lang":"eng","text":"Fabrication of curved shells plays an important role in modern design, industry, and science. Among their remarkable properties are, for example, aesthetics of organic shapes, ability to evenly distribute loads, or efficient flow separation. They find applications across vast length scales ranging from sky-scraper architecture to microscopic devices. But, at\r\nthe same time, the design of curved shells and their manufacturing process pose a variety of challenges. In this thesis, they are addressed from several perspectives. In particular, this thesis presents approaches based on the transformation of initially flat sheets into the target curved surfaces. This involves problems of interactive design of shells with nontrivial mechanical constraints, inverse design of complex structural materials, and data-driven modeling of delicate and time-dependent physical properties. At the same time, two newly-developed self-morphing mechanisms targeting flat-to-curved transformation are presented.\r\nIn architecture, doubly curved surfaces can be realized as cold bent glass panelizations. Originally flat glass panels are bent into frames and remain stressed. This is a cost-efficient fabrication approach compared to hot bending, when glass panels are shaped plastically. However such constructions are prone to breaking during bending, and it is highly\r\nnontrivial to navigate the design space, keeping the panels fabricable and aesthetically pleasing at the same time. We introduce an interactive design system for cold bent glass façades, while previously even offline optimization for such scenarios has not been sufficiently developed. Our method is based on a deep learning approach providing quick\r\nand high precision estimation of glass panel shape and stress while handling the shape\r\nmultimodality.\r\nFabrication of smaller objects of scales below 1 m, can also greatly benefit from shaping originally flat sheets. In this respect, we designed new self-morphing shell mechanisms transforming from an initial flat state to a doubly curved state with high precision and detail. Our so-called CurveUps demonstrate the encodement of the geometric information\r\ninto the shell. Furthermore, we explored the frontiers of programmable materials and showed how temporal information can additionally be encoded into a flat shell. This allows prescribing deformation sequences for doubly curved surfaces and, thus, facilitates self-collision avoidance enabling complex shapes and functionalities otherwise impossible.\r\nBoth of these methods include inverse design tools keeping the user in the design loop."}],"citation":{"chicago":"Guseinov, Ruslan. “Computational Design of Curved Thin Shells: From Glass Façades to Programmable Matter.” Institute of Science and Technology Austria, 2020. <a href=\"https://doi.org/10.15479/AT:ISTA:8366\">https://doi.org/10.15479/AT:ISTA:8366</a>.","ieee":"R. Guseinov, “Computational design of curved thin shells: From glass façades to programmable matter,” Institute of Science and Technology Austria, 2020.","apa":"Guseinov, R. (2020). <i>Computational design of curved thin shells: From glass façades to programmable matter</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:8366\">https://doi.org/10.15479/AT:ISTA:8366</a>","short":"R. Guseinov, Computational Design of Curved Thin Shells: From Glass Façades to Programmable Matter, Institute of Science and Technology Austria, 2020.","ista":"Guseinov R. 2020. Computational design of curved thin shells: From glass façades to programmable matter. Institute of Science and Technology Austria.","mla":"Guseinov, Ruslan. <i>Computational Design of Curved Thin Shells: From Glass Façades to Programmable Matter</i>. Institute of Science and Technology Austria, 2020, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8366\">10.15479/AT:ISTA:8366</a>.","ama":"Guseinov R. Computational design of curved thin shells: From glass façades to programmable matter. 2020. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8366\">10.15479/AT:ISTA:8366</a>"},"publication_status":"published","ddc":["000"],"related_material":{"record":[{"status":"deleted","relation":"research_data","id":"7151"},{"id":"7262","relation":"part_of_dissertation","status":"public"},{"status":"public","id":"8562","relation":"part_of_dissertation"},{"status":"public","id":"1001","relation":"part_of_dissertation"},{"status":"public","id":"8375","relation":"research_data"}]},"alternative_title":["ISTA Thesis"],"title":"Computational design of curved thin shells: From glass façades to programmable matter","ec_funded":1,"doi":"10.15479/AT:ISTA:8366","year":"2020","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"ScienComp"}],"page":"118","file_date_updated":"2020-09-16T15:11:01Z","supervisor":[{"full_name":"Bickel, Bernd","last_name":"Bickel","orcid":"0000-0001-6511-9385","first_name":"Bernd","id":"49876194-F248-11E8-B48F-1D18A9856A87"}],"status":"public","type":"dissertation","day":"21","date_created":"2020-09-10T16:19:55Z","file":[{"file_id":"8367","creator":"rguseino","relation":"main_file","content_type":"application/pdf","success":1,"access_level":"open_access","date_updated":"2020-09-10T16:11:49Z","checksum":"f8da89553da36037296b0a80f14ebf50","date_created":"2020-09-10T16:11:49Z","file_size":70950442,"file_name":"thesis_rguseinov.pdf"},{"file_id":"8374","creator":"rguseino","relation":"source_file","content_type":"application/x-zip-compressed","access_level":"closed","date_updated":"2020-09-16T15:11:01Z","checksum":"e8fd944c960c20e0e27e6548af69121d","date_created":"2020-09-11T09:39:48Z","file_size":76207597,"file_name":"thesis_source.zip"}],"department":[{"_id":"BeBi"}],"has_accepted_license":"1","degree_awarded":"PhD","language":[{"iso":"eng"}],"publisher":"Institute of Science and Technology Austria","date_published":"2020-09-21T00:00:00Z","month":"09"},{"has_accepted_license":"1","degree_awarded":"PhD","department":[{"_id":"BeBi"}],"file":[{"file_name":"Thesis_Ran.zip","file_size":1245800191,"date_created":"2020-09-14T01:02:59Z","checksum":"edcf578b6e1c9b0dd81ff72d319b66ba","date_updated":"2020-09-14T12:18:43Z","access_level":"closed","content_type":"application/x-zip-compressed","relation":"source_file","file_id":"8388","creator":"rzhang"},{"date_created":"2020-09-15T12:51:53Z","checksum":"817e20c33be9247f906925517c56a40d","file_name":"PhD_thesis_Ran Zhang_20200915.pdf","file_size":161385316,"date_updated":"2020-09-15T12:51:53Z","access_level":"open_access","success":1,"file_id":"8396","creator":"rzhang","content_type":"application/pdf","relation":"main_file"}],"date_created":"2020-09-14T01:04:53Z","month":"09","date_published":"2020-09-14T00:00:00Z","publisher":"Institute of Science and Technology Austria","language":[{"iso":"eng"}],"page":"148","file_date_updated":"2020-09-15T12:51:53Z","day":"14","type":"dissertation","status":"public","supervisor":[{"last_name":"Bickel","full_name":"Bickel, Bernd","orcid":"0000-0001-6511-9385","first_name":"Bernd","id":"49876194-F248-11E8-B48F-1D18A9856A87"}],"alternative_title":["ISTA Thesis"],"related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"486"},{"id":"1002","relation":"part_of_dissertation","status":"public"}]},"ddc":["003"],"doi":"10.15479/AT:ISTA:8386","year":"2020","acknowledged_ssus":[{"_id":"SSU"}],"ec_funded":1,"title":"Structure-aware computational design and its application to 3D printable volume scattering, mechanism, and multistability","article_processing_charge":"No","date_updated":"2023-09-22T09:49:31Z","oa":1,"publication_identifier":{"issn":["2663-337X"]},"_id":"8386","oa_version":"Published Version","project":[{"grant_number":"642841","_id":"2508E324-B435-11E9-9278-68D0E5697425","name":"Distributed 3D Object Design","call_identifier":"H2020"},{"grant_number":"715767","_id":"24F9549A-B435-11E9-9278-68D0E5697425","name":"MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and Modeling","call_identifier":"H2020"}],"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","acknowledgement":"The research in this thesis has received funding from the European Union’s Horizon 2020 research and innovation programme, under the Marie Skłodowska-Curie grant agreement No 642841 (DISTRO) and the European Research Council grant agreement No 715767 (MATERIALIZABLE). All the research projects in this thesis were also supported by Scientific Service Units (SSUs) at IST Austria.","citation":{"apa":"Zhang, R. (2020). <i>Structure-aware computational design and its application to 3D printable volume scattering, mechanism, and multistability</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:8386\">https://doi.org/10.15479/AT:ISTA:8386</a>","ieee":"R. Zhang, “Structure-aware computational design and its application to 3D printable volume scattering, mechanism, and multistability,” Institute of Science and Technology Austria, 2020.","chicago":"Zhang, Ran. “Structure-Aware Computational Design and Its Application to 3D Printable Volume Scattering, Mechanism, and Multistability.” Institute of Science and Technology Austria, 2020. <a href=\"https://doi.org/10.15479/AT:ISTA:8386\">https://doi.org/10.15479/AT:ISTA:8386</a>.","mla":"Zhang, Ran. <i>Structure-Aware Computational Design and Its Application to 3D Printable Volume Scattering, Mechanism, and Multistability</i>. Institute of Science and Technology Austria, 2020, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8386\">10.15479/AT:ISTA:8386</a>.","ama":"Zhang R. Structure-aware computational design and its application to 3D printable volume scattering, mechanism, and multistability. 2020. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8386\">10.15479/AT:ISTA:8386</a>","ista":"Zhang R. 2020. Structure-aware computational design and its application to 3D printable volume scattering, mechanism, and multistability. Institute of Science and Technology Austria.","short":"R. Zhang, Structure-Aware Computational Design and Its Application to 3D Printable Volume Scattering, Mechanism, and Multistability, Institute of Science and Technology Austria, 2020."},"publication_status":"published","abstract":[{"lang":"eng","text":"Form versus function is a long-standing debate in various design-related fields, such as architecture as well as graphic and industrial design. A good design that balances form and function often requires considerable human effort and collaboration among experts from different professional fields. Computational design tools provide a new paradigm for designing functional objects. In computational design, form and function are represented as mathematical\r\nquantities, with the help of numerical and combinatorial algorithms, they can assist even novice users in designing versatile models that exhibit their desired functionality. This thesis presents three disparate research studies on the computational design of functional objects: The appearance of 3d print—we optimize the volumetric material distribution for faithfully replicating colored surface texture in 3d printing; the dynamic motion of mechanical structures—\r\nour design system helps the novice user to retarget various mechanical templates with different functionality to complex 3d shapes; and a more abstract functionality, multistability—our algorithm automatically generates models that exhibit multiple stable target poses. For each of these cases, our computational design tools not only ensure the functionality of the results but also permit the user aesthetic freedom over the form. Moreover, fabrication constraints\r\nwere taken into account, which allow for the immediate creation of physical realization via 3D printing or laser cutting."}],"author":[{"id":"4DDBCEB0-F248-11E8-B48F-1D18A9856A87","first_name":"Ran","full_name":"Zhang, Ran","last_name":"Zhang","orcid":"0000-0002-3808-281X"}]}]