Shell (structure)

A shell is a three-dimensional solid structural element whose thickness is very small compared to its other dimensions.

It is characterized in structural terms by mid-plane stress which is both coplanar and normal to the surface.

A shell can be derived from a plate in two steps: by initially forming the middle surface as a singly or doubly curved surface,[1] then by applying loads which are coplanar to the plate's plane thus generating significant stresses.

Typical applications include aircraft fuselages, boat hulls, and the roofs of large buildings.

The ideal thin shell must be capable of developing both tension and compression.

Shell structure of the TWA Flight Center Building by Eero Saarinen , John F. Kennedy International Airport , New York
The Forest Opera , an open-air amphitheatre in Sopot, Poland, with a membrane roof.
Great Court , with a lattice thin-shell roof by Buro Happold with Norman Foster , British Museum , London