ETH Zuerich - Startseite
Professur für CAAD

 


caad d-arch


Caad Teaching
 

 
Bachelor of Architecture: CAAD II ss07

 
Master of Advanced Studies
in Architecture, CAAD


 
DWF-Processing
Programmieren statt Zeichnen


 
Graustufen - Ein Atlas
Schweizer Wohngebäude als XML Daten


 
DWF- Denken in Systemen:
In Collaboration with the Technical University Vienna


 
Seminarwoche:
BlowUp


 
Archiv

 
Caad Projects
 

 
Theory
 
Design
 
Building
 
Practice

 
Related pages
 

 
Swiss Federal Institute of Technology Zurich
 
Institute of Building Technology
 
Faculty of Architecture

 
Other pages

 










hbt d-arch

Altmetall_051202-17.jpg

under pressure

INHALT In der diesjährigen Seminarwoche der Professur für CAAD wird eine selbstentwickelte materialeffiziente Metallkonstruktion einem Belastungstest in der HIF-Halle ausgesetzt. Vier Gruppen werden unter jeweils einer „Unterkonstruktion“ von 80x180x80 cm Grösse entwerfen und produzieren. Vom Entwurf, über Finite-Elemente-Simulationen bis hin zur computergesteuerten Produktion werden moderne Methoden des computergestützten Entwerfens und Produzierens praktisch angewendet.
Die erste Phase der Seminarwoche bildet eine Auseinandersetzung mit der Technologie der Blechbearbeitung über Entwurf hin zur Blechkonstruktion. Es werden aktuelle Produktionsmöglichkeiten präsentiert und von den Teilnehmerinnen in die Projekte integriert. Es entsteht eine digitale „Produktionskette Blech“.
Die zweite Phase widmet sich der Umsetzung und Realisation des Konzeptes. Im Einsatz kommen computergesteuerte Werkzeuge, welche state-of-the-art der CNC-Metallverarbeitung sind (Lasern und Stanzen, pneumatisches Biegen, Hochfrequenz- und Punktschweissen).
In der dritten Phase des Kurses finden Belastungsproben der Konstruktionen statt. Die Simulationen, die mit einem CAD-Programm, das Finitenelementen rechnet, erzielt werden, werden mit realen pneumatischen Belastungsproben verglichen.
Die Konstruktion, die das beste Verhältnis zwischen Gewicht und Tragfähigkeit erzielt hat, hat gewonnen.

DAUER Montag 27. November bis Freitag 1. Dezember 2006
ORT Zürich und Umgebung (keine Übernachtungen)
TEILNEHMERZAHL 12 Studierende
KOSTEN 150.-
Im Preis inbegriffen: Material, Benutzung der CNC - Maschinen, verschiedene Exkursionen und Vorträge .
ANMELDUNG 50.-(Anmeldung via Internet)
SPECIAL Die Teilnahme an der Seminarwoche berechtigt die Studierenden zum selbstständigen Benutzen der Metallwerkstatt des D-ARCH


Professur für CAAD Ludger Hovestadt: Prof. Dr.Ludger Hovestadt, David Sekanina, Oskar Zieta
Institut für Baustatik und Konstruktion, Prof. Dr. Mario Fontana


zsammen_k.jpg

Under Pressure: Digital production and optimization of sheet metal structures

The goal of this one-week workshop was to build a sheet metal structure as lightweight and as stable as possible, bridging a given gap. A parametric 3D modeler was used to build the structures. The same 3D data was used to structurally test the objects virtually, alter their dimensions to optimize stress distribution, flatten the sheet metal components and send this 2D data directly to a CNC laser cutter and CNC bending machine. After bending and assembling the sheet metal parts, the constructions were structurally tested on a stress-strain bench. Using one CAD dataset from concept through optimization to manufacturing, production time was drastically shortened, tight tolerances were maintained, hence the assembly was simplified and errors were reduced.

Abstract:

The advancements of parametric 3D modelers and finite element analysis applications, paired with the progress in CNC manufacturing, empower today’s architect building unique, complex and structurally sane sheet metal structures in a short time. To prove this point a one week workshop was held where the students were asked to build a sheet metal structure as stable and lightweight as possible, in the given dimension of 800*1800*800mm, using only 1mm thick steel. By using a parametric 3D modeler with integrated sheet metal functions, the structure could be modeled in its final bent and assembled state. Each component could be flattened directly in the software checking for overlaps. Using a top-down construction methodology, where new parts depend on dimensions and constraints of existing parts, the whole assembly updated automatically, when the dimension of one part were changed, allowing to change the statics of the whole assembly with a few clicks. With the finished assembly, the optimization cycle would start using finite element analysis (FEA) software. The FEA software used for the first tests lacked the nonlinear buckling analysis functions, essential for this task. We had to switch to a more powerful FEA application. The results of these virtual stress tests led to changes to the original structure, trying to distribute the stresses evenly. Now an optimization cycle would start where newly changed structure would be tested again until the buckling stresses were minimized. All parts were modeled as sheet metal parts in 3D. This enables the user to flatten the parts virtually and using the flat contours directly to create the 2D data that was sent to the CNC laser cutter. The precision of today’s CNC laser cutters and bending machines leads to highly precise bent sheet metal parts, simplifying and speeding up the assembly considerably. Very tight tolerances can be maintained, reducing structural instabilities due to imprecision. Various assembly methods were used in our five structures that were built. Pop rivets, spot welds, bolts and linear welds. Finally the constructions were mounted on a stress-strain bench. As the hydraulic cylinder could only pull, not push, the structures were mounted high up on columns with their ‘feet’ loosely attached to them and then pulled down from the center. Gradually the pulling force was elevated and the resulting displacements were measured automatically, resulting in a flow of data which then could be translated into a graph plotting the stress-displacement curve.

To our and the professor’s astonishment the structures were far more stable than we thought. Most of us initially thought that the structure would support a load of roughly 1300 to 1500 Newton. But even the weakest structure didn’t fail before applying a load of 6000 Newton. The strongest structure even supported a load of 37 kN.

Conclusion:

While in other industries sheet metal constructions are widely used, architects still fear of using them as a supportive structure. With this workshop we tried to show that within digital production chain a complex and statically safe structure can be built out of thin sheet metal parts in a short time.

Film:

under pressure _ film_1.jpg

Revision r1.3 - 02 May 2007 - 14:46 - OskarZieta
Parents: WebHome
Copyright © 1999-2003 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Extern.UnP moved from Extern.UndP on 13 Jul 2006 - 14:52 by OskarZieta - put it back