Research Pavilion - Lehrstuhl für Tragwerksplanung

INSIDE\OUT Research Pavilion at the central campus of the TUM

The INSIDE\OUT Pavilion at the main TUM campus was completed in October 2017. (Photo: Martin Ley)

This research project investigates a technique to construct double curved gridshells from straight lamellas and identical, rectangular nodes. The newly developed design method is based on so-called asymptotic curves on a minimal surface. The research was conducted in three phases:

Theoretical investigation of the geometry, 3D-modelling and structural analysis
Development of a construction technique using physical models and prototypes
Design and construction of a large-scale architectural gridshell

The first timber model an asymptotic network based on a minimal surface. (Photo: Denis HItrec)

In the first phase we investigated the geometric properties of surface strips along asymptotic curves, and defined principle requirements for the design and construction of asymptotic grids. Subsequently a digital workflow was developed to design and refine minimal surfaces, generate a quadratic network of asymptotic curves, and process the 3D information to produce construction drawings for a 2D fabrication. Simultaneously we developed a method to analyse the load-bearing behaviour of these strained gridshells, using an FE-modelling software. The residual stresses are calculated based on the curvature values of all three profile-axes (x, y and z).

An enneper minimal surface was used to test the quadratic layout, and superimposition of asymptotic and principal curvature lines.

The construction process of asymptotic gridshells was investigated using physical models. This allowed us to examine the global behaviour of a spatial grid as well as the local behaviour of a single lamella. Based on these insights we constructed two prototypes (timber and steel) to compare fabrication, assembly and load-bearing capacities. Based on these prototypes, we determined a precise fabrication and construction procedure for the large-scale architectural gridshell.

The first prototype was constructed from 3mm thick timber lamellas. The two families of lamellas were assembled in separate levels and are connected with square timber studs. (Photo: Eike Schling)

The second prototype was assembled from 1.5mm thick steel lamellas. We used a bottom-up construction process, which allowed for a flat assembly of the lamellas and a subsequent elastic transformation into the final three-dimensional shape. (Photo: Eike Schling)

The third and last phase implemented the insights of our theoretical and practical investigation to design and build an architectural project. All planning phases had to be completed starting with the design of a bespoke minimal surface and ending with a detailed plan of the building logistics.

The design surface is generated through the transformation of a catenoid (left). The shape is thus adjusted to the building site.

INSIDE\OUT is the first architectural structure that utilizes the geometric potentials of asymptotic curves to construct a strained gridshell. The minimal surface is designed to adapt to the complex outlines of our green building site. The 90m² large steel grid embraces a tree creating a central courtyard.

An automated process is used to create the construction drawings. Each node-to-node distance is measured and labelled along a straight rectangular strip. These strips are later laser-cut from 1.5mm thick stainless steel and delivered to our site at the TUM.

The construction itself relies on very simple processes. The lamellas are cut straight and flat, and can be easily manufactured and transported. They can be slotted together by hand into flat segments. Once all the joins are fixed, these segments are elastically bent into their curved geometry. By fixing every node to 90 degrees and adding extra edge supports, we can freeze this shape. INSIDE\OUT consists of nine of these segments, which are later combined on site, like a large 3D puzzle. By adding edge profiles, supports and bracing, this structure becomes an efficient, load-bearing gridshell.

The straight lamellas are bent and interlaced by hand into flat segments. The segments are then transformed elastically into their three-dimensional shape. (Photo: Eike Schling)

The INSIDE\OUT pavilion consists of 9 strained segments, which are bolted together on site.

INSIDE\OUT has a span of 9 x 12m. The experimental pavilion displays a new method to construct freely designed shapes with very simple and affordable processes. The spatial curvature of the grid enables an efficient load transfer as gridshell.

View from underneath the INSIDE\OUT pavilion. The grid of elastically bent steel lamellas is overlaid with a diagonal grid of cables. (Photo: Felix Noe)

The pavilion is designed around a central tree creating a circular courtyard and two archways. (Photo: Felix Noe)

The pavilion was completed in October 2017. Further investigations are currently being processed. In the following months we aim to develop a façade system for this asymptotic structure which will be installed in 2018.

The pavilion will house several events for the 150th anniversary celebration of the TUM in 2018. A façade cover is currently developed and will be installed in 2018. (Photo: Felix Noe)

Publications

Schling, E.; Barthel, R. (2017): Experimentelle Studien zur Konstruktion zweifach gekrümmter Gitterstrukturen. Fachwissen. In: Detail structure 10/17 (01), p. 52–56.

Schling, E.; Hitrec, D.; Barthel, R. (2017): Designing Grid Structures Using Asymptotic Curve Networks. In: Klaas de Rycke, et al. (Hg.): Humanizing Digital Reality. Design Modelling Symposium Paris 2017. Springer Singapore, p. 125–140.

Schling, E.; Hitrec, D.; Schikore, J.; Barthel, R. (2017): Design and construction of the asymptotic pavilion. In: Bletzinger, K.-U. et Al (Hg.): VIII International Conference on Textile Composites and Inflatable Structures. p. 178–189.

Schling, E. (2017): Aufwendiges einfacher planen. Ratgeber Produktivität. In: M&T Metallhandwerk (10.2017), p. 32–34.

Schling, E.; Barthel, R. (2017): On spatial networks. In: TUM Fakultät für Architektur (Hg.): Jahrbuch 2016/17. p. 82–89.

Planning Team:

Chair of Structural Design
Prof. Dr.-Ing. Rainer Barthel

Dipl.-Ing. Architekt Eike Schling

Cand. Ing. Denis Hitrec

M.Sc. Jonas Schikore

Student team for prefabrication and assembly:

Beatrix Huff, Andrea Schmidt, Viktor Späth, Miquel Lloret Garcia, Maximilian Gemsjäger

In cooperation with:

Erhard Brandl GmbH & Co. KG, Metallbau, Eitensheim

Technisches Zentrum, TUM, Matthias Müller, Schlossermeister

Supported by:

TeDa (Isogeometrische B-Rep Analyse), Lehrstuhl für Statik, TUM

Prof. Helmut Pottmann, Institute of Applied Geometry, TU Wien

Evolute, The geometry experts, Wien

Pfeifer, Seil- und Hebetechnik, Memmingen

Funding:

Faculty for Architecture

Dr. Marschall Foundation

Leonhard Lorenz Foundation

ARI / Architectural Research Incubator