Membrane
The Membrane interface can be used for very thin objects, like cloth, where only in-plane forces are important. Membranes can be considered as plane stress elements, but with an arbitrary, possibly curved configuration is space.
In most applications, a membrane must be pre-tensioned in order to have a stable configuration, so it will almost invariably be used in a geometrically nonlinear analysis. The only exception is when it is used as a ‘cladding’ on top of a solid, since it will then be stabilized by the solid.
In the Membrane interface a large number of different material models can be used.