Nikolas Früh

Zusammenfassung

Coreless filament winding is a robotic fabrication technique in which conventional filament winding is modified to reduce the core material to its minimum. This method was showcased and developed through a series of pavilions demonstrating its potential to create lightweight structures. The latest project, Maison Fibre, goes one step further and adapts the fabrication into a hybrid structure combining fibre-polymer composites (FPC) with laminated veneer lumber (LVL) to allow for walkability. The result is the first multi-storey building system fabricated with this novel technique. During the integrative design process of the slab system, the optimum fibre layup was negotiated between the timber support span, load induction, boundary conditions, and material amount required. A total of four iterations of the hybrid component were load tested and compared with the maximum enveloped forces resulting from the global structural simulation. The full-scale load tests were used to calibrate the refined structural simulation of the slab components. The experimental process allowed for material reduction and validated the structural system's capability to withstand the design forces. In addition, the fibre layup was tailored and load adapted for the non-tested wall and slab components of the installation using the test results and achieving further material optimization. This publication describes the integrative design process of the hybrid slab system from initial concepts to the iterative optimization of the structural system, demonstrating its potential for future applications.

Zusammenfassung

The multi-stage filament winding (MSFW) method enables the sustainable production of lightweight fibre composites with complex geometries. Double curved components, even with undercuts, are analysed and concave areas which are not suitable for filament winding are replaced by convex temporary geometries. Permanent and temporary mandrel parts are combined for the stage-based fabrication method. The sand composites developed for MSFW mandrels can be washed out using water. The sand can be reused. This paper introduces the fabrication method, presents the status of the research, and focuses on the geometry generation algorithm of the integrative design process.

Zusammenfassung

The ICD/ITKE Research Pavilion 2016/2017 is the most recent in the series of experimental building demonstrators developed by the Institute for Computational Design (ICD) and the Institute for Building Structures and Structural Design (ITKE) at the University of Stuttgart. The completed structure is a 12 m long cantilevering lattice-composite shell that was wound in one piece by a multi-machine fabrication system using coreless filament winding. To realise such a structure through this fabrication process involved a negotiation between architectural design, structural requirements and fabrication constraints. The structural design process was divided into two steps. A shell model was used to evaluate possible geometries in the initial negotiation between architectural design and fabrication constraints. In order to approximate the highly anisotropic material behaviour of fibre reinforced polymers, substitute material properties had to be determined in physical tests. In the second step the actual fibre layup was analysed using a detailed beam-element model. The main load bearing fibre bundles were directly analysed in cross section and position. As-built and intended geometry were constantly compared and the feedback was used to refine the finite element analysis during fabrication. This paper covers the aspects mentioned and gives an outlook on further possibilities of this design and fabrication approach.

Zusammenfassung

Die Realisierung von Schalentragwerken aus Stahlbeton ist anspruchsvoll. Hohe Anforderungen an Planung und Ausführung sowie damit verbundene Kosten führen dazu, dass diese Tragwerkstypologie nur selten realisiert wird. Der Artikel beschreibt das Schalungssystem, das beim Bau des zukünftigen Stuttgarter Hauptbahnhofs zum Einsatz kommt. Zahlreiche Anforderungen führten zu der Entwicklung von massiven Brettsperrholzbauteilen, deren Oberfläche mit faserverstärktem Kunststoff beschichtet wird. Die Fertigung der Bauteile erfolgt in mehreren Stufen. Nach der Herstellung von Brettsperrholzrohlingen werden aus mehreren Schichten Rohkörper zusammengesetzt. Die Formgebung erfolgt in zwei Schritten. Mit einer Plattenbearbeitungsanlage werden die Konturen der einzelnen Schichten gefräst. Die endgültige Form wird von einem Industrieroboter herausgearbeitet. Nach der Beschichtung wird die Form der Bauteile mithilfe eines Laser‐Scanners verifiziert. Alle Prozesse während Planung und Fertigung der Schalungselemente sind weitgehend modellbasiert. Mit dem entwickelten Schalungssystem wurden die ersten Elemente des Schalentragwerks aus Weißbeton bereits erfolgreich betoniert.