tensile surfaces - cad logic - slitting

Tensile Surfaces/ Slitting

Cad Logic_SS09dia_MArch ProgramHochschule Anhalt

Hochschule Anhaltdia_MArch Program / SS09Cad Logic_Slitting

Professor: Daniel DendraProject by: Tudor Cosmatu Claudia Meléndez

Dessau, July 2009

Index

Intro

Phase I > Physical Models <

Phase II > Analysis of the Physical Model translated to the computer <

Phase III > Digital Model <

Intro> From physical model to digital environment <

Tensile surfaces comprises a series of experiment based on slitting. The main goal of this work was to explore different slitting techniques applied to specific materi-als creating physical models that then were analysed, and the most succesful model was translated to the digital realm.

For the final result, Tensile surfaces depart from a single mesh < a cylinder >, then the continuity of the surface is interrupted by slits and finaly the resulting new edges of the surface are re-joined setting some parameters in order to have again a continuous, but more complex surface. Pattern of Model 5

Phase I> Physical Models <

The first stage of this project includes 13 physical mod-els that explore different possibilities of slits <straight, curviliear, “V” and “X” cuts> using different materials. The first models, from 1 to 5, are free explorations. From this first set of models, some characteristics inherited in model 4 and 5 were taken for the next models, in order to create a single surface. Finaly the last models, are an exploration of how to rebuild a continuos tensile surface, after slitting it. This condition was the main idea for the digital model.

Models 1 to 3> Slits on a plane <

In these models straight and curvilinear slits were applied to a plane, using two different materials: plastic and paper. The slits varied in scale, direction and arrangement. After the plane was cut, some external pressures were applied in specific locations of the surface, in order to explore how the material deformed due to the slits and these external forces.

Phase IModel 1_ Curvilinear slits on plastic surface

Tensile Surfaces / Slitting Both pages> Model 2_ Straight slits on paper

Phase I

Tensile Surfaces / SlittingModel 3_ Straight and Curvilinear slits on paper

Models 4 and 5> Slits on fabric <

Another set of models were done using fabric. In Model 4 a single “X” cut was applied on the surface and then, some vertices of the fabric were fixed on a wooden frame and the fabric was then tensioned through an air column, to expand the tensile characteristics of the mesh. The result was a curvilinear surface with a 3D behavior in the center of the mesh.

In the case of Model 5, curvilinear and straight cuts were done in a random way in order to explore how the slits deformed when the fabric is attached to a frame. The emerging pattern had an interesting ornamental feature when two layers of fabric overlaped and are exposed to the light effects.

Tensile Surfaces / Slitting Model 4_ “X” cuts on polyamid fabric

Phase IModel 5_Curved and straigth random cuts (varying length and direction)

Tensile Surfaces / Slitting Both pages> Model 5

Phase I

Tensile Surfaces / Slitting

Materials & dimensions

polyamid fabricl= 12 cmw= 8cm

cardboardl= 21 cmw= 14 cm

wooden sticksl= 9 cm

Models 6 to 9> Slits on fabric <

In this set of models, the same rules of Model 5 were applied on a fabric, but setting some parameters for such as, length, number and displacement of the slits.

The main feature of these experiments are the ornamental con-dition created on the surface, accomplished by overlaping the slitts patterns and using the tensile characteristic of the elastic material.

Top> Materials for the models / Bottom left> Model 7

Phase I

Model 7 > straight radial slits in a spiral progression of 0.5 cm per slit.

Length> 0.5 - 6.5 cm_ 1 cm far from the center.

Model 9 > straight slits in a growing density pattern, vary-ing length and direction.

Model 6 > straight radial slits on the center of the fabric.

Length > 2cm_1 cm far from the center.

Model 8 > straight radial slits in a spiral progression of 0.2 cm per slit.

Length> 0.5 - 1.6 cm.

M6

M7

M8

Bottom left> Model 9 / Top right> diagrams for Model 6 to 8 / Bottom right> Models 7 and 8

Tensile Surfaces / Slitting Top> Model 6 / Bottom> Model 7

Phase ITop> Model 8 / Bottom> Model 9

Tensile Surfaces / Slitting From top to bottom> Models 6 to 8

Phase IFrom left to right> Models 6 to 8

Tensile Surfaces / Slitting Models 6 to 9

Models 10 to 12> Tensile surface <

The purpose of these experiments was to explore tech-niques which could create the sensation of a tensile surface. Linked “X” cuts were created on either two sides or all four sides of the surface. The resulting “V” shape fabric elements were rotated and fixed on the wooden frame.

Tensile Surfaces / Slitting

Materials & dimensions

polyamid fabricl= 12 cmw= 8cm

cardboardl= 21 cmw= 14 cm

wooden sticksl= 9 cm

“X” cutl= 4 cm

Model 10

The fabric was stretched to the opposite corners of the wooden frame, obtaining a cylinder shape. Then, 1 “X” cut was created at the center of each lateral face of the cylinder, and the resulting vertices were rotated and joined in order to create again a tensile surface.

Both pages> Model 10

Phase I

Tensile Surfaces / Slitting

Materials & dimensions

polyamid fabricl= 17 cmw= 8cm

cardboardl= 21 cmw= 14 cm

“X” cutl= 5 cm

Model 11The same rule of Model 10 was applied to obtain a cylinder shape. Then, 1 “X” cut was created at the center of two lateral faces of the cylinder.

The resulting 4 vertices < on each face > were stretched to the corners of the frame, rotating them 45° to 90° from their initial potition.

Both pages> Model 11

Phase I

Tensile Surfaces / Slitting

Material & dimensions

wooden framel= 34 cmw= 11 cm

polyamid fabricl= 37 cmw= 9 cm

“x” cutsl= 5 cm

For this model 6 “X” cuts were made along the vertical axis on two faces of the cylinder < 3 cuts per face >, then the resulting “V” shapes were stretched to the corners of the wooden frame, rotating them in an angle progression of 45°. As a result, a single surface was created again.

FACE “A” FACE “B” FACE “C” FACE “D”

34 cm

17 cm17 cm17 cm17 cm

12

34

56

78

910

1112

1314

1516

1718

1920

2122

2324

1 2

34

8 7

59

10

1112

6

14

13

15 16

17

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24 23

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Model 12

Top > Diagram for Model 12 / Bottom right > Model 12

Phase IModel 12

Tensile Surfaces / Slitting Both pages> Model 12

Phase I

Diagrams> <

Model 13> Tensile surface <

For the last model, the same parameters of Model 12 were applied but creating an array of columns. In this case, the first column use the same parameters of model 12, the third column is a 180° mirror and upside down image of column 1; and the middle column is a random arrangement of the vertices, linking the outter columns.

Phase IModel 13

Tensile Surfaces / Slitting Both pages:> Model 13

Model 13

Phase II> How to translate the Physical Model

to the digital realm? <

For this stage the characteristics of Models 12 and 13, were considered, taking from them the first condition of the cylinder, applying the “X” cuts to its faces and then fixing them to points that were defined in the dia-gram of Model 12.

The digital models were built using the Nurbs Relax-ation Rhino Script. On a given surface, subdivisions are created, and then tension and restrictive parameters such as corners and edges are working in order to “re-lax” the starting surface.

However, the first attemps were not enough satisfac-tory, given the fact that the curvature of the surfaces were not following the idea of a single surface, it means that the edges were visible where they were not supossed to be.

Phase II

FACE “A” FACE “B” FACE “C” FACE “D”

34 cm

17 cm17 cm17 cm17 cm

12

34

56

78

910

1112

1314

1516

1718

1920

2122

2324

1 2

34

8 7

59

10

1112

6

14

13

15 16

17

18

19

20

21

24 23

22

Diagram for Model 12, used to rebuilt the model in the digital realm

Tensile Surfaces / Slitting

Phase IIBoth pages > First attempts of the digital model

The final process> Iteration of the digital model <

For the final model, Models 12 and 13 were studied again and instead of considering them as a vertical object, they were analysed it in their horizontal form. This time, the arrangement and unions of the physical models were not used literrally, instead, the parame-ters for the digital model were based on the logic of the connections. Moreover, the points where the tension would be applied were defined, and finaly the digital model was created.

By applying different forces on the selected points, the shape and behavior of the object changes. Therefore, by having the same logical arrangement, but different tensile forces, a number of spatial arrangements can emerge.

Phase II

Iterations of the digital model

Tensile Surfaces / Slitting

Iterations of the digital model

Phase II

Iterations of the digital model

Phase III> Tensile surfaces <

The final model can be considered as a flexible space, which can have different uses: as a bridge, a path, a pavilion or a place to relax.

Phase III

Front View

Side View

Tensile Surfaces / Slitting

Phase III

Tensile Surfaces / Slitting

Phase III

Tensile Surfaces / Slitting

Phase III

Tudor Cosmatu &Claudia Meléndez