We looked at the paper entitled 'Linking Hanging Chain Models to Fabrication' by Axel Kilian as a source of information and inspiration to carry out our next experiment. The next experiment mainly had to focus on utilizing digital form finding methods to add to our methods for producing the next prototype.
Axel Kilian, Ph.D. Candidate in Computation, Department of Architecture, School of Architecture and Planning, Massachusetts Institute of Technology, Cambridge, MA.
SUMMARY OF PAPER
Fabrication output is an integral part of the iterative process and not a post design process.
The relationship between form finding model and the translation into volumetric form was explored in a series of small models.
His Motivation :
Equilibrium solutions can be scaled if the proportional distribution of mass is kept and the geometry of the lines of forces is scaled proportionally. This holds true even though mass does not scale proportionally to geometric dimensions.
A major disadvantage is that a physical model is hard to measure accurately and
in reasonable time, as measuring requires physically accessing the model. The
measurement of forces within the strings of the model is even more difficult, as it
requires the installation of strain gauges, which is time consuming and can potentially
disturb the model. In addition, the measurements are not part of the design process. The
design is frozen to allow for iterating through the load measurements throughout the
model in one given state
The digital version, in contrast, allows simultaneous measurement and creating/editing of
geometry. These measurements can directly drive other dimensions in the model. In the
digital model, editing and creating the string weight is less limited by the availability and
preparation of the physical material, which in the case of a very complex model can
substantially slow down the process. Furthermore, the use of generative techniques
allows for the rapid placement of complex string constructs and observing their behavior
before investing time into an elaborate physical model
The self-weight of the load-bearing member contributes only negligible
amounts to the structure locally and therefore does not substantially affect the hanging
curve form. If there is no load present other than the weight of the structure itself, the
self-weight becomes the dominant form giving factor. The cross section has to provide
enough area for the forces traveling through it. A further optimization of the structure, for
example with the aim of achieving uniform compressional loading throughout the same
material, which would be possible by varying thickness, was not undertaken by Gaudi.
Islers Conclusion : page 8
Isler identifies instabilities in his shells as follows: First, at the
supports second, due to general buckling; third, due to local buckling of the free edge (for
which the counter curvature is so important)
Designing in dynamics vs. analytical approach. Design by discovery : Page 10
Structural and dimensional evaluation of form is not an afterthought but an essential of
the design process. This is where the learning by discovery enabled by interactive tools comes into play. In interaction with a live, force-geometry linked structure, a designer can directly observe the range of structural responses while exploring possible forms. This encourages an explorative approach to design and supports unconventional solutions that integrate and respond to the designer’s intent.
1. form finding,
2. topology finding,
3. load path finding,
4. material distribution
5. testing for structural redundancy
Form finding techniques in an interactive digital modeling environment can support the
design process by giving continuous feedback to the designer, allowing the designer to
integrate structural principles into the creation of form rather than to structurally optimize
the finished form at the end of the design process.