This paper introduced the inverse finite element method (IFEM)
for degenerate solid shells. The IFEM is particularly well suited for
the inverse design of compliant mechanisms (in this case, shell-like
mechanisms) whose task is to attain a desired shape after large
elastic deformations. As a good example of an application of the
IFEM, the design of a passive valve was undertaken in this paper.
Such a design can also be achieved using an optimization technique,
where an FEM problem is solved at each iteration. Here, it
was achieved by solving only one IFEM problem.
Further, in the light of the current applications, we observe once
again (see our previous papers on 3D solids [3] and beams [4–6])
that the solution of the nonlinear equilibrium equation when the
undeformed configuration is unknown (the case of the IFEM) takes
considerably fewer iterations than the solution of the same equation
when the deformed configuration is unknown (the case of
the FEM).
Last but not least, since degenerate solid-shell FEM – unlike the
stress-resultant shell FEM – makes use of the governing equations
from Solid Mechanics, it makes possible to reuse the standard
material libraries.