HYBIOS 4.0/ Modeling Construction Logistics

After working with the shell prototypes using building scale materials, the construction logistics started  to become clearer. It became apparent that we needed to push the material upwards and tension it down, instead of using the cubic frame we used before. 

We devised a construction system, similar to Mechano toys, where the components of the system could be adjusted for height and angle to create differentiated variable spaces.

The result of the interior finish turned out a bit rough, but the system works so far. The fabric sagged while drying, due to some faults in the design of the system. It was also hard to finish and cut some elements inside. We plan on fixing those problems while working out the next prototype.

Slab Deflection Test/ Reinforcment Comparison

A deflection test was carried out for 6 different slabs with different reinforcement materials, to compare the structural integrity of different wall assembly options. Slab 00 started with no reinforcement, Slab 1.1 + 1.2 were reinforced with a concrete cloth and a metal mesh respectively. Slab 2.1 + 2.2 were reinforced with metal meshes of different porosities.

 Slab 3.0 was reinforced with BarChip fibre and a hexagonal mesh. The results clearly show that BarChip is an excellent material choice for the re-inforcement of shotcrete for the use on the freeform mesh. The BarChip  fibre reinforced slab broke at a weight of 247, which is amazingly stronger than any other reinforcement option we have tested.

Thank you to Elasto Plastic BarChip for sending in samples for us to test: http://www.elastoplastic.com/

Fabric / Concrete Cloth Testing

The past two weeks we decided to get our hands dirty, and take a stab at material testing. 

We tested the fabric that we have been using to create the HYBIOS and several other fabrics, such as cotton and scrim. We used a meter to measure the weight devised from pulling, as well as the displacement threshold before the material would break. The materials were tested on a 1000x1000x1000 mm frame.

Concrete cloth was tested at 4 mm thickness. The maximum displacement was about 400 mm, after which the concrete cloth would break.

A curvature analysis and a displacement calculation were produced. We modeled the resultant form that was the result of pulling the Concrete Cloth at the center. The displacement calculation would help us in setting limits for the next analogue and digital experiments. ANSYS was used to create the displacement chart of an 8 mm  concrete shell with steel mesh reinforcement. 

The Material was hydrated and left to set completely for about 24 hours. 

Many problems were encountered, but the material successfully deformed using the pulling and tensioning method. We noticed that pushing the material up with a stick produced lesser deformed curvatures. Creases and ripping should be avoided.

DigiHYBIOS 1.0 & AnaHYBIOS 3.0 / New Approach: From Digital FormFinding to Analogue Methods

With the latest HYBIOS, we adopted a new approach. This time the experiment was based on a digital FormFinding algorithm using Daniel Piker's Kangaroo Plugin for Grasshopper. The new experiment also resolved some of the issues of the previous experiment. 

A cellular grid was used to generate a frame for pathways to have a more even floor to walk on. This time, the modeling was done to scale. Points were restricted at the pathway edges to create ramps on the raised platform. The mesh was relaxed within the grid cells to create blob-like forms by restricting the outlines of the grid. The roof membrane was stretched towards the center of the cells. The idea is to create a circulation path within the space, where depressions within the grid cells could be used for seating etc. Although more control was gained over the digital FormFinding process, there were a lot of restrictions with using the algorithm. Material behaviour and mesh qualities could not be embedded within the logic of the algorithm. Deforming the mesh was not done in real time either, which was a major restriction. We would like to create a script eventually that solves the problems of the current tools we are using and calculates the forces as output.

We deployed the same logic with the analogue prototype. The results were approximately similar, although we have more control over the shaping process, which enabled us to generate more interesting archi-tectonics. The idea of the developed formwork is that the floor grid could be reused to cast several other HYBIOS. The model was constructed to a scale of 1:50 for a 20m x 20m space. Essentially the point of this experiment is to control the reusable formwork to form the structures.

Analysis of Previous Experiments / Prototypes

In order for us to move forward with the project in a more effective manner, we started with analyzing what we have done before. The previous prototypes (Hybios 2.0 & 2.1) were analyzed mainly for the methods used and the resultant geometries obtained by these methods. The results and failures of each prototype were documented to give insight for the problems that need to be solved in the next prototype.

The main intention of documenting the choreography of the random stretching procedures is to obtain a draft for a set of instructions, or a 'pseudo code' for the construction team to carry on the construction.

A quick experiment to obtain a clearer mapping of the curvatures of the generated topologies was carried out. A grid was projected onto the surface of the prototypes. The intention being to give purpose for the these curvatures rather than just being manipulators of the internal space. Possible environmental responses such as sheltering canopies at entrances and channeling rainwater were discussed.

Research Development: New FormFinding Methods_ Experiment 2.1

The objective of the second attempt was to manipulate the geometry from the interior to the exterior. The focus was to hide and reveal while stretching, to make the spaces of the interior more inhabitable. Disks were utilized to create light-wells to draw light into the interior spaces. The fabric was painted with thin layers and was sprayed with compressed air at the top to distribute the mix into the strings. The result was a pixelated gradient of transparency along the light-wells creating interesting lighting conditions.

 

Research Development: New FormFinding Methods_ Experiment 2.0

For the second formfinding method, we utilized a frame-based system where the sides of the frame are marked with holes on a grid. Two overlapping layers of fabric were used, the fabric was stretched by pulling string through the holes.  Different methods of stretching were utilized, such as overlapping the nodes, stretching one layer into the other and tying the edges. The fabric was then painted with thin layers of plaster, glue and water consecutively. The strings were cut when the shell has hardened and the HYBIOS was sanded and cropped around the edges .

 

Results: AnaHYBIOS 1.3 & 1.4

After refining the material formation process, the analogue modeling method yielded interesting geomoetries. These geometries were observed and measured, especially for their spatial and structural qualities. 

First Analogue Prototypes

Our first few attempts at the analogue prototypes. The method tested was to hang fabric and pull it at nodes by applying a force, in this case the weight hung. Different weights were tested on a voronoi cell frame with differentiated cell sizes. The process was refined through testing different models and some failed protoypes. The method works by tensioning the fabric and freezing it with a plaster compound. The materials utilized resemble the properties of tensioned membranes (fabric) and compression properties of concrete (plaster).

FormFinding

A great research paper by Philippe Block. Formfinding has been used in architectural models to create spatial forms that are optimized for structure while in the design phase. The Phd Thesis proposes a digital formfinding tool as an alternative to traditional formfinding methods adopted by Frei Otto and Gaudi. The paper gave us a lot of insight on how to start with our design experiments.