Hyperbolic Paraboloids ~ the true hyperbolic paraboloid shell roof
shape is generated by moving a vertical parabola (the generator)
over another vertical parabola (the directrix) set at right angles
to the moving parabola. This forms a saddle shape where
horizontal sections taken through the roof are hyperbolic in
format and vertical sections are parabolic. The resultant shape is
not very suitable for roofing purposes therefore only part of the
saddle shape is used and this is formed by joining the centre points
thus:-
To obtain a more practical shape than the true saddle a straight
line limited hyperbolic paraboloid is used. This is formed by raising
or lowering one or more corners of a square forming a warped
parallelogram thus:-
For further examples see next page.
Shell Roof Construction