Retractable roofing
Looking at my page of photographs of other
applications of pleating suggests that a significant
motivation for using pleating would be expected to be that it
provides a mechanism for producing flexible, deformable or
reconfigurable structures.
In the context of roofing structures, the most significant
type of movable structures that are required are
retractable structures.
There are three main types of retractable structure that pleating
helps with.
- Structures that fold up like a concertina or a fan;
- Structures that consist of sliding panels;
- Structures that roll up.
A number of folding retractable roofs exist:
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| Vienna City Hall Courtyard
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There are sliding panel designs - such as the Komatsu dome in Japan.
Use of a pleated fabric panel results in a lightweight
result - and creates a convenient rectangular panel with
parallel edges.
Since pleating does not cause a substantial extension into
the third dimension, sliding panels of pleated material can
be stacked up when retracted - to increase the fully exposed
area.
Lastly a "roll-up" design would operate as shown in the following three diagrams:
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| Roll-up retractable pleated roof pattern
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The function of the third stage is to to create the pleated
pattern.
It puts the entire membrane into tension, provides it with
support - and eliminates any flat or horizontal regions.
Links
Sergio Pellegrino's ring
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