Anticlastic

Also called saddle surface, synclastic

Curved in opposite directions along two axes, like a saddle; hyperbolic paraboloids and tensile membranes are anticlastic. Its opposite, curved the same way in both directions like a dome, is synclastic.

Rules that use the word

A membrane must be a saddle. A fabric or cable-net roof is stable only if it is prestressed into an anticlastic (saddle) shape, curved upward in one direction and downward in the other, so that wind from either side meets a surface already in tension.

Where it appears in the book

In the chapters Frame and Skin.

Nearby in the glossary

Anda · Ang · Anta · Antarala · Apadana · Apophyge · Apron moulding · Apse