Fabric Formwork 2.0 (Shuangying Xu, Yuxin Qiu)

Traditional rigid formwork has distinct disadvantages for casting complex forms from concrete. Moreover, the wood formwork of a specific component can hardly be reused after disassembly. This work is based on the result of the previous fabric formwork project, with the optimization in more accuracy and controllability.

Using ABMs to integrate design into fabrication and assembly process, to better interact and control in real time with the fabrication of linear concrete component with fabric formwork.

- Manipulating material: Portlandzement CEM I 42,5 R

- Formwork material: Lycra (max. Tension 175%)

- Sensor: Webcam

The general workflow is separated into three parts:

(1) Design with design space (catalog)

(2) Simulation (ABM for shape forming) and Sensing (Webcam for shape detecting)

(3) Fabrication and Assembly

The height difference of two ends of the component will cause the position of max. curvature change, which will be later used to recognize the gravity orientation from design to fabrication. Meanwhile the length difference will determine the shape and thickness of the unit, especially the middle area.

The generate process is separated into six steps:

(1) Definition of geometry to form

(2) Slicing to reference curves in layers

(3) Waving on the reference curve in individual roughness, defining agents

(4) Segmentation to unit components

(5) Balance finding of the system by number of supporting

(6) Aligning to gravity orientation with max. curvature position, get unit to be fabricated

All reasonable possibilities were collected into a catalog of units standardized in 5 cm as fabrication choices, which will also be the design space. The average curve of each unit will be used to select needed shape and compare with the fabrication result. The reason for this process is to make the fabrication more controllable and improve the fabrication efficiency.

We introduced the control point of the waving curve as boid agents. The system is separated into digital and physical parts.

The digital part is used for behavioral deciding the shape to fabricate. In order to keep balance, we defined a series of behaviors of wandering and balancing. The agent will keep on moving and seeking if there are less than 4 intersection points with the lower layer, while stopping when there are 4.

The physical part is used for controlling the fabrication process. Because of the special gravity defined shape of the units, we will never achieve exactly the same curve. The containment behavior will enable the robot to slightly adjust the shape to get closer to the design requirement. We have a seeking behavior to compare the real time shape of mid curve sensored by Webcam with the designed one. When the averaging tolerance < 2cm and the maximum tolerance < 3cm, the adjusting process will stop. The fabrication is thus finished.

The real time shape detect takes place throughout the whole process of the fabrication and assembly. During the fabrication, it will be used to control the tolerance and to update the physical fabricating result back to the digital simulation. During the assembly, it will be used to check if the assembling position is correct and to realize the possible design changes. When design is changed by an intended different assembly from planned, the fabrication of the following component will be recalculated.

We try to finish one entire loop of design - simulation - fabrication - assembly. Possible application will be forming a self-standing free-curving wall.

Future possibilities will be adding human interaction in more processes, automatically detecting the catalog by a behavior in ABM System as well as using AR to help with the assembling process.