The author looks at ways of generating exact solutions for elastic mem
branes. Several methods are discussed using the radial expansion of a
disk as an example. First, the author uses known solutions for three-d
imensional plane strain deformations of a cylinder and show that these
can be interpreted as membrane solutions. Second, the author shows ho
w to generate new exact solutions for the plane strain problem using a
technique in which the equilibrium equations are decoupled into two s
ets of equations: one for the deformation and one for the required str
ain energy function. Both two- and three-dimensional membrane theories
are considered, and some differences are highlighted.