Glass fiber & resin composite

Aim and Intent:

The experiment works with a composite material of glass fiber and resin, resin works as a hardener and binder to the glass fiber. The fabric is pinned to the framework and the form is derived through the gravitational force acting on it. A series of experiments were done earlier in SEA to explore the possibilities of the apparatus that makes material forms under gravitational influence. It explores the logic of the frame - work to allow material forms.The first diagram, which is the catenary arch, is derived from the earlier experiments at SEA.  For which the Fabric is hanging freely and acting under its own weight, supporting at its end points.With only gravitational force and no other load acting on it. 

The concept of minimal surface  is then introduced on the catenary surface by adding a pinch to it. The term "minimal surface" is used because these surfaces originally arose as surfaces that minimized total surface area subject to some constraint. Frei Otto used the concept of minimal surface, by dipping a wire frame into a soap solution, forming a soap film. 

The pinch enforces a amount of tension to the suspended glass fibre in gravity. By pinching the surface the curves of the surface join each other at a point which reduces the suace area at a point and makes it more stable.  Glass fiber is a mesh and can be suspended and stretched to a form which helps it to work on the principle of minimal surface by spanning the smallest area to a given boundary.

By clamping the glass fibre at two ends and apply resin.

              Wodden Frame (18” x 18” x 18” )                                                                             Glass fibre fabric                                                                                         Clamps

Steps 1

Experiments to know the material and the forces acting on it.

• Make a frame work to clamp the ends to form a catenary arch.

• Pinch the fabric at a distance. ( variable)

• Apply layer of resin on glass fiber (Layer 1)

• Let it dry

• Add random mesh of glass fiber (Layer 2)

• Apply another coat of resin

Experiment 1

Apparatus : Wooden framework 18” x 18” x 18”

                   Fabric length : 24”

                   Fabric width  : 16”

                   Fabric sag     : 7”

Observation : The catenary arch increases its fall as we apply resin to the glass fiber.

 The Pinch makes the form more stable by adding a third dimension to the volume.

As we applied resin the surface started to widen itself due to the weight which made the surface flatter near the pinch. 

Learnings :  As the fabric is away from the pinch it gets flatter. As the width of the fabric increases the area gets flatter.

Experiment 2 :  

Apparatus : Wooden framework 18” x 18” x 18”

                   Fabric length : 25”

                   Fabric width  : 25”

Observation : As we vary the end points of the fabric clamp the catenary curve changes its form.

Experiment 3:

Apparatus : Wooden framework 18” x 18” x 18”

                   Fabric length : 25”

                   Fabric width  : 6” (shorter side)

                   Fabric width  : 12” (longer side)

                   Pinch (center) : 8”

Learnings : The shorter the length the  curves get more flatter. And the depth of the surface increases.

Experiment 5:

Apparatus : Wooden framework 18” x 18” x 18”

                   Fabric length : Stretched to maximum

                   Fabric width  : 12” (longer side)                 

Objective :  To understand the gravitational force acting on the

                   Glass fiber after application of resin.

Conclusion : The tension in  the fabric increases resulting in a wider opening at both the ends

Experiment 6:

Apparatus : Wooden framework 18” x 18” x 18”

                   Fabric length : 30”

                   Fabric width  : 12” (longer side)                 

Learnings: As the length of the fabric increases, the sag increases which changes the 

                     Shape of the curve resulting into a more deeper curve.

Steps 2

Experiments to work out a 1:1 pavilion unit with a pinch.

Apparatus : Wooden framework

                   Fabric length : 42''

                   Fabric width  : 12” (longer side)                 

Objective :  To achieve a pavillion from different units.