First test in STAAD

To explore the set up of the new process, we tested a basic hexagon dome structure, parametrically built in GC, on structural performance in STAAD. The results are clear.

the tension is obvious caused by the horizontal thrust, which would be most efficiently translated into vertical forces bij tension ring(s) in regular dome structures.. So the hexagonal grid automatically divides these forces among its members on the spot where its needed.
blue: compression
red: tension
supprt/load conditions: simple pinned supports and a 1 N/m2 load





the deflection is very clearly demonstrated in this movie:



next steps:

• exploring radiolarian skeletons (relation between their shape and forces acting on them)
• defining approach
• modelling a new parametric model according to approach
• testing, analysing different configurations
• genetic optimization loop

get back to you soon..

One step back. Research Approach

I looked back into the radiolarians in order to decide on a renewed approach for the dome project. Please check the image below for some key observations.


Radiolarian dome shape principles

If we want to use the dome shape for architectural purposes, it could be of interest to integrate some features in the parametric model as seen in radiolarians as well. Taking in consideration, the dead load, the gravity, and the supports,we already know that a combination of radial vertical beams in combination with rings and diagonal beams for stability will work in architecture (Geodesic dome Buckminster Fuller). what seems interesting to me, learning from radiolarians, is: In which ways would some of their basis principles work for architectural purposes? The first option is, to take one homogenic grid and manipulate the density and the overall shape. The second option focusses on dividing the dome in horizontal strokes, devided by rings while manipulating the different grids in between.

objective: achieve a structure which is as light as possible and at the same time stiff enough to stand the load cases.

Approach option 1:
use a fixed grid structure for example the combined hexagonal en pentagonal grid. (this principle based on the buckyball/c60 molecule is considered as an optimal manner to devide a sphere into planars or straight beams). What the interesting part could be in this case, is that while optimizing the overall shape of the dome, its environment can be taken into consideration. That could be the support of the structure (straight ground, inclined ground) and the load case, focussing on wind from one main direction. An homogenic structure has a high potential of being able to be fabricated out of a limited range of prefab elements.

parameters: shape of dome, density of homogenic grid
fixed: material, grid type, constraints and load cases
criteria: lightness of structure
results: different dome shapes with certain density of grid. Optimized for a specific situation. (i.e. an inclined site at the sea side).

Approach option 2:

Taking the applications of rings in the dome as a starting point, we could divide the grid into multiple horizontal strokes, as seen in radiolarian skeletons (see image 6th example). Generate separate grids structures in between the rings. In this case its an option to design the grid based on some well known mechanical behaviours of architectural shells and domes. (i.e. small density in top, mainly vertical beams in base, etc. )

parameters: density of each grid stroke, type of grid per stroke (! GC might could exchange grid types)
fixed: material, overall shape of dome, constraints and load cases.
criteria: lightness of structure
results: Different combinations of grid configurations within one dome shape.

I will do some more research of dome structures and discuss it with my tutors Peter and Michela, in order to decide.

To be continued..

After the completion of the course Stand-up Architecture, I will continue the project in co-operation with Peter von Buelow and Michela Turrin. Based on the conclusions of my paper (posted in previous message), we will adjust the concept model into a dome structure and adjust the optimization loop. I hope to publicate and present the results on a conference in the end of the summer this year.


Set-up of dome structure in GC

FINAL PAPER

You can download the pdf via this link: Research Paper Structural DNA

FINAL PRESENTATION

Check here the slides of the Final Presentation | 23th of March:

Test phase 4 - Genetic Optimisation of structure

Today and yesterday i've been randomly creating generation 0 of panels (see image of screen shot below) and breeding the 1st generation based on the best ranked members of generation 0.

Peter von Buelow ( http://www-personal.umich.edu/~pvbuelow/ ) has guided me intensively during this process. The constantly adjusted parameters of the members are being generated by his Genetic Algorithm linked to a customized website (image below). The website makes it possible to download a datafile, which can be read by GC. The dxf file of the panel is then loaded in the Finite Element software STAAD-Pro, which optimizes the construction applying different sizes of steel tubes. It calculates the total weight of the structure and the ratio of structural performance. This output is uploaded to the website again, which will visualize the new best ranked members.
This optimization loop can be repeated untill the results approach an optimum according to the previously defined criteria.

Link to the GC-GA Population website: http://www.frames.tcaup.umich.edu/radiolaria/


screen shot of breeding website white= gen 0, grey=gen 1

Test phase 3

Wow, it is a bumpy ride I must admit!
I just generated a population called generation 0.
I realized after a few hours of breeding, saving, pasting, generating, that the GC file was a bit expired.

I've tried to generate a population for an updated combined configuration (see image below) too, but this didnt work, because the GA has to change first to get that properly done (and i'm not able to do this myself yet)

After an inner discussion I've decided to keep these results and finishing the GA process with them soon. These structures, are all squeezed (see image below). So it wont be possible to construct a facade with only these types of panels. I decided to calculate a few types of the stretched out panels (image below), manually in STAAD-Pro. Because I'm interested in the different structural behaviour of these two types.


configuration of squeezed panel


configuration of stretched panel


Note: Together these two types of panels could form a continuous surface (facade).



configuration of combined panel

I considered to calculate these kind of combined panels before, but I guess that the option of either squeezed and streched panels will work better structurally because they are more symmetrical than this example.

Of course, a radial structure will be the best, taking in consideration the nature of most radiolarian skeletons, but for this course I stick to these panels. It is a more zoomed in approach. So not a complete radiolarian, but a part of it.

Below you see stretched and squeezed panels forming a continuous surface. I prefer the lower one, because the grid is in the same direction.

continuous surface sketch