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Freeform Geometries in Wood Construction

Diploma Thesis at TU Vienna
Author: Marko Tomicic
Supervisor: Prof. Dr. Helmut Pottmann

“Freeform Geometries in Wood Construction” is the title of a diploma thesis conducted by Marko Tomicic at the Technical University of Vienna under the supervision of Prof. Dr. Helmut Pottmann, which was published in October of 2013. The thesis explores the possibilities of rationalization for complex architectural geometries in order to simplify the building process, especially the building with wood.

Main Topics

  1. Wood as a Construction Material
  2. The Geometry of Freeform Architecture
  3. PQ Meshes
  4. Developable Surfaces and DStrips
  5. Geodesics Curves on Freeform Surfaces
Freeform Geometries in Wood Construction

Freeform Geometries in Wood Construction

Abstract

Despite being one of the oldest construction materials on earth and having numerous advantages over modern high tech construction materials, wood has been greatly marginalized in the construction of today’s increasingly popular freeform architectural shapes. Architectural freeform shapes must be rationalized prior to their building due to their large scale. This work explores planar quadrilateral mesh panelizations, rationalizations with developable mesh strips and rationalizations with geodesic patterns in combination with new computational tools and scripting as ways to use wood for the construction of voluptuous freeform architectural structures. For each of the above rationalization techniques a project is designed, rationalized for and detailed for the manufacturing in wood.

 

About the Author

Marko Tomicic is an architect based in Vienna, Austria.  During his studies at the Technical University of Vienna he became interested in complex architectural geometries and started working at the consulting company Evolute, where he published the EvoluteTools Pro Scripting Primer. He continuously collaborates with researchers from TU Vienna and KAUST University on numerous research projects in the field of architectural geometry. Since 2014 Marko Tomicic works in the Advanced Geometry Engineering [AGE] group at Waagner Biro in Vienna.

Contact
@Marko_Tomicic

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Freeform reciprocal frame system

NIB Reciprocal Frame Freeform

Reciprocal frame system applied to a freeform, workshop hosted by NIB

This four day workshop was held in Salerno in September 2013 with Daniel Piker and Gennaro Senatore as tutors. The goal was to design and build a reciprocal frame system from a freeform surface, helped by the new kangaroo tools Daniel was developing. You can have an idea of what a reciprocal frame system is reading my article on Nexorade, bear in mind that traditionally these structure were conceived to work only with compression shear forces, but negative curved surfaces inevitably bring to traction shear forces, that’s why it was necessary to use plastic strings to keep the assembly together.

You can download the Grasshopper definition and the output file here.

Day 1

The two tutors introduced themselves and we did the same. The team was composed by people who already knew Grasshopper but for others it was the first time. The tutors introduced the software and what probably is its most renowned plugin Kangaroo, which we would have extensively used.

Day 2

Daniel explained how to use Kangaroo to form find membranes in in pure tension and asked to produce a nice surface compliant with the space where the pavilion would have been put. That surface would then have been used as a base for the reciprocal system.

We started from a triangular mesh, since that’s the arrangement we wanted for the reciprocal system. The boundaries where fixed, whilst the inner ones where used as springs with rest length equal to the initial one. A uniform upward load was applied, so that the actual structure would have resisted vertical (gravity) loads. To produce a good surface it’s helpful to use a clean mesh possibly close to the final shape, in fact during relaxation each spring produces a force proportional with its deformation. The best would be to iteratively relax a mesh and then use it as starting mesh, until all the members elongates to the same amount.

The mesh was then refined using Picker’s remeshing tool which takes advantage of Plankton which brings the Half-Edge data structure into Grasshopper. We ended up having a neat triangular mesh, ready to be transformed into a reciprocal system!

Day 3

The reciprocal system was found using Kangaroo’s component, checking that the resulting structure would stand without the members sliding one over each other. The processed followed until now bought to a structure which worked in pure axial force and shear, with no additional bending. That being done, before fabrication we had to number each stick and to know which and where other sticks crossed the former. This was done creating a grasshopper definition.

Day 4

We built it! We started by numbering each plastic tube (they were all the same) writing in the middle its number and on its edges a line showing where the other two would connect and what were their number. The sticks were fixed using rubbers so they won’t have slid and plastic strings.