Fabric formed wax folding test

This week we attempted to study how the folding patterns developed through a tensile net using “ridges” and “valleys” might be further explored by replacing the sharp “valley” folds (previously created by downward pulling strings) with curved valleys created by the weight of liquid wax (to mimic the influence of ice on the fabric).  The model we used was the same interlaced diamond pattern that we had used previously that we now layered that with a synthetic/natural fiber blended fabric.  Using a heated modeling table, paraffin wax was used to simulate liquid water (pre-freezing). Magnets were used to hold down the fabric pattern to the table, while strings attached to the frame around the table introduced the tension necessary to achieve the vaulting form.  Once formed and the liquid wax was applied to the fabric layer, the heat was turned off to rigidify the model.

The resulting model showed some deformation of valleys caused by the wax, but some areas were less obvious due to the scale of the structure in comparison to the size of the folds in the pattern and the inability to create even and precise tension field on the cable net structure pulling up.  In addition, due to the overall stiffness of the fabric and the number of facets on the vaulting form (causing there to be shallower valleys between the peaks) this model proved difficult to decipher.

The next step will likely include a scaling up of the fabric model on this heated wax table as well as using a pattern that has deeper folds in order to gain a more dramatic topography between the ridges and valleys produced by the tension net.

fabric formed wax test_01fabric formed wax test_02

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Physical Origami Cable Model Test 1

The pattern used to create the first origami form was studied to translate the folding of paper to the linking of cables to form the ridges and valleys. In order to do this we proposed that the fabric layer being folded would form ridges through the use of cables pulling from under the fabric, and form valleys through the cables pulling down on top of the fabric. This approach allowed us to divide a standard folding pattern into two separate patterns, a ridge pattern and a valley pattern. In physical form this would allow us to first construct a ridge cable pattern, then introduce a fabric layer and then conclude with a valley cable pattern on the top. The intersections of the valley and ridge patterns would be then coupled through a hole in the fabric.

By using an odd number of spaces between intersection points in the x and y directions, we are able to achieve a continuous woven pattern using a single cable for both the ridge and valley patterns.We first began to test this approach by leaving out the fabric and only building the cable model of the origami pattern. We used posts (screws) on a plywood sheet to weave the ridge pattern and valley patterns and zip tied them together. After attaching leads to each intersection we used the digital model to locate appropriate anchor points and then used a wooden frame to pull the intersections of strings to. The resulting form is shown in the pictures here. Because of the inaccuracies of the construction and the varying tensions in the pulled points the pattern had loose and overly taught areas, but the overall form was achieved as hoped. We will next try to introduce a fabric layer into the this assembly method.

 

Physical to Digital and Back

Our interest in the direction of this project is to construct a relationship been the digital and physical design process so that one feeds into the other and influences the methods of full scale construction.

In this project we intend to utilize an origami folding pattern with a fabric formed ice sheet. The advantage of using origami as a forming technique is that it has the ability to produce rigid stable forms with shear planes, can be formed using non-stretch materials, and made using non-customized sheet patterns.

 

In order to do this, we are intending to use high-tensioned cables to form the mountains and valleys in the folding pattern to shape the fabric panel. This process will require a translation to move from the techniques required to produce a folded rigid non-stretch plane (like paper) to a edge formed pattern that guides a non-stretch but pliable fabric plane. To begin this we developed a grasshopper model in order to visualize the folding pattern in real time. This model allowed us to develop a pattern language of “valleys” and “ridges” and to choreograph the forces required to manipulate this pattern through Grasshopper and Kangaroo 2. We are beginning with a simple folded pattern that would create a folded barrel vault (capable of being self supporting with an anchored base). With this test pattern we are attempting to find the mechanical behaviour of the ridges and valleys and the points of intersection which join them. Once this is achieved we will use this technique to allow for the exploration and rapid visualization of other origami folding patterns.

The ongoing intent of the digital script is to mimic the physical properties of the material (cable, fabric) and actions (via construction techniques) being used in this project. This allows for the study of the digital through the representation of the physically built structure. At the present time the grasshopper script only mimics ridged body typologies (such as timber struts or planer faces) and not rope or cable topological forms.

 

Site Reconnaissance/ Reconstruction

Utilizing the techniques of photographic reconstruction (photogrammetry) we surveyed the site of the project with a small quad copter. This fly over allowed for the capture of a single video with intersecting flight paths so that post processing of the video would result in a high overlap of imagery which is conducive to photogrammetry reconstruction of a dense point cloud.

The reconstructed 3 dimensional point cloud was then aligned with our on site measurements and scaled appropriately. The computational reconstruction was run through Pix4D. The 1:1 point cloud was then brought into Rhino to be used as a graphic for future development and as a tool for accurate site measurements. The images here show the resulting point cloud and overall measurements of the site we intend to work on.