Author Archives: Diana Chan

Otto d-Rive

ottod-rive

P2C_Diana Chan

FREI OTTO WOOL THREAD MACHINE TO SEEK FORM

Frei Otto is a German architect and structural engineer well known for his leadership on lightweight tensile and membrane structures since earning his doctorate in tensioned constructions in 1954.  He founded the Institute for Lightweight Structures at the University of Stuttgart in Germany in 1964.  At this institute, Frei Otto studied path optimization in the 1990s.   Using machines that restructure materials, Otto relies on a machine to seek form.  Specifically, Otto’s wool-thread machine has been used to calculate city patterns since the machine “economizes on the number of paths” by merging geometries.  A web of multiple wool threads that resemble multiple lines, each with two endpoints fixed on the same circle are submerged underwater.  When the system of wool threads is taken out, individual threads merge together creating a complex two-dimensional organization of solids and voids.

ANALOG COMPUTING THAT CACULATES ORGANIZATIONAL FORM

Frei Otto’s wool-thread machine is a form of an analog computer.  Analog computers use a continuously changing aspect of a physical phenomenon to model a problem being solved.  Otto’s wool-thread machines change the degree of freedom that water (a physical phenomena) can act on the wool threads.  By changing the degree water acts on the wool threads, Otto solves the problem of path optimization.  The end geometry is a result of material interaction, elasticity, and variability.

FREI OTTO AS ADAPTIVE SYSTEM COMPLETE WITH FEEDBACK LOOP

To simulate Frei Otto’s wool-thread machine, one can use Autodesk’s Maya hair simulation.  Curves in Maya are drawn and endpoints constrained.  These curves are then rebuilt with multiple points to give the curves more manipulation flexibility.  By assigning the curves to behave as Maya hair, the hairs would normally drip down  (if constrained) or simply fall due to the force of gravity when the animation is run; however, by tweaking the hair system’s setting known as “Collide Width Offset” one determines the surrounding distance each curve considers other hairs for collisions.  When the animation is run after tweaking “Collide Width Offset” the hairs merge as in Frei Otto’s wool-thread machine.

Both Frei Otto’s wool-thread machine and Autodesk’s Maya hair simulation are adaptive systems.  An adaptive system is defined as “a set of interacting or interdependent entities, real or abstract, forming an integrated whole that together are able to respond to environmental changes in the interacting parts”.  The wool-threads, or Maya curves modeled as a hair system, together with their own constraints, respond to the changes in the degree the water acts on the wool threads or to the changing “Collide Width Offset” the curves consider other hairs for collisions.  Maya’s hair system can also adapt to a collision sphere set by the user.

With the presence of multiple actions here, changing the “Collide Width Offset” and introducing collision spheres, it becomes evident that a feedback loop is present.  A feedback loop is defined as “a process in which information about the past or the present influences the same phenomenon in the present or future”.  Maya’s hair simulation is not linear.  The animation does not perform and finish one action, the merging of the hairs, before considering the effects of the collision spheres.  In fact, Maya’s hair simulation calculates the “Collide Width Offset” and the collision spheres simultaneously or in a feedback loop.  This can be tested by changing either the “Collide Width Offset” or changing an attribute of the collision spheres while the animation is running.  While the animation still runs, the changes affect each other as well as the entire system.

FREI OTTO IN URBAN LANDSCAPE AND ADAPTIVE ARCHITECTURE: BUILDING AND LANDSCAPE

<In progress paragraph on how Frei Otto is used in P1 and P2>

Emergent City

Jorge Luis Trevino Garza

Parametricism

Patrik Schumacher

http://www.patrikschumacher.com/Texts/Parametricism%20-%20A%20New%20Global%20Style%20for%20Architecture%20and%20Urban%20Design.html

Performative Architecture

Edited by: Branko Kolarevic & Ali M. Malkawi

http://books.google.com/books?id=2SkJOQasOyYC&pg=PA167&lpg=PA167&dq=frei+otto+wool+thread+study&source=bl&ots=hG_9JeCuce&sig=79L6ReD-LgTv7flxwScjbTYe3gM&hl=en&sa=X&ei=GuxUUeLOOOPx0wHW1IH4DQ&ved=0CDAQ6AEwAA#v=onepage&q=frei%20otto%20wool%20thread%20studyfrei&f=false

P2B_Diana Chan

P1F_Diana Chan

P1E_Diana Chan_Schematic



LINK:

https://www.dropbox.com/s/moxjxkaxfucfyaz/SD.pdf

P1D_Diana Chan_Timothy Perkins_Joe Russel_Anders Rustin


Please check out our video experiment to see what happens when you “pokeface” the fabric: https://vimeo.com/58387905 !

P1C_Diana Chan : Shadow and Pedestrian/Vehicular Perception as Parameters


For my concept I assumed a site on the water between a pedestrian and vehicular bridge. The above image inspired me to explore shadows and views from the speed of a car and a speed of a pedestrian as parameters that fabric can respond to.

Using grasshopper and a heliotrope plugin, I was able to project a bridge’s shadow onto a plane. Then I used a hexagon attractor script to set up a field that reacts to a curve–I set the curve to be the shadow of the bridge so I now have response to shadows. When a shadow is cast onto fabric, the fabric could be more transparent than the area of fabric in sunlight. But how do we change the transparency/opacity of fabric?

Learning from our physical model, stretching a mesh will change the transparency/opacity of the material.

Fabric modeled in maya with apertures that anticipate casted shadows was then stretched to reveal that the fabric undulates, grows thin, and then swells. This kinetic response will inspire a fabric skin to respond in the same way to the bridge’s shadows.

The fabric skin then will be in perpetual motion both perceived on the exterior as well as the interior.  Additionally, “holes” like seen in the image above will provide peeks in from cars and people crossing the bridge.  Larger holes will serve the speeding cars and smaller holes will serve slower-moving pedestrians.

P1_Diana Chan_King Fahd

King Fahd Stadium in Riyadh, Saudi Arabia FACTS:  Architects: Ian Frasier / John Roberts & Partners.  Engineers: Horst Berger of Geiger Berger Associates (Roof Designer).  Constructed: 1983-1986.  Material:  PTFE-coated Fiberglass Fabric (non-structural).  Structure: Cable and Masts.  Cost: 80 million.  Capacity: 75,000 seats.  Achievements: is one of the largest stadium roofs; pays cultural homage to Arabic Bedouin tents; shades and responds to climate and desert context

The first thing to catch your eye is the fabric.  The fabric material is PTFE-coated fiberglass.  The fabric membrane roof is NOT structural; instead, a cable system of suspension and stabilizing cables act as 1) the structure providing redundancy and stiffness, and 2) the framework for installing the fabric.

The roof is expressed as 24 identical tent units arranged into a circle, resembling the Arabian Bedouin desert tents.  24 vertical masts arranged in a smaller circle of diameter 247m form the main supports for the tents (the Houston Astrodome is only 216m in diameter and can fit inside the King Fahd).  The masts with rear anchor cables and ring cables form a stable structural system that does not require participation of the fabric.   This means that fabric panels can be replaced while the existing structure stands.

The cable structural system is economical in creating efficient space.  Even with its central opening (required by soccer rules), the roof is one of the largest stadium roofs in the world, covering a plan area of 47,000 square meters.  (The roof was also designed so that the roof could have been closed without changing the system.)  The tent forms absorb sound, let warm air rise, and give a large interior space a sense of intimacy through its gentle curves.  Viewed from the exterior, the steep folds of the tents give the stadium its powerful image.  The fabric, cantilevering 56m out, acts as a large umbrella shading the seats and concourse slabs in a hot desert location.

Tents are made of two repetitive fabric panel shapes that are stressed between ridge cables, valley cables, and edge catenaries.  Ridge cables connect to the top of the masts and hold the system up while valley cables connect to the bottom anchors holding the system down.  Forces are transferred outwards via these upper and lower radial cables that are not connected.  Instead of being linked via a compression ring, they are linked to the vertical and slanting masts and cables.  The roof is not a real looped cable roof since the inner ring cable is wholly sealed.

This project speaks to how large the scale of a fabric structure can become.  It speaks to how the fabric material is almost an ideal choice because it pays homage to the Arabic Bedouin tents and how the fabric appears to be in its natural use–to shade people.  It’s also interesting that the fabric appears to be intimate and peaceful from the inside, but also convey power from the outside.  In this project, the fabric structure is also modular.  The question that I have then is could the fabric have been structural or more integrated with the structure rather than being a fabric that just lies on top of a frame?

SOURCE:http://www.tensinet.com/database/viewProject/3748http://www.sbp.de/en/build/sheet/18-King_Fahd_Internationales_Stadion.pdf

GOOD READ ON TENSILE STRUCTURES:  http://www.sciencedirect.com/science/article/pii/S0141029698000224