  Interference-fit joints are typically adopted to produce permanent assemblies
among mechanical parts. The resulting contact pressure is generally used for
element fixing or to allow load transmission. Nevertheless, some special
designs take advantage of the contact pressure to induce desiderata deformation
or to mitigate the stress field inside the structure. Biased interference
fitting between a planar mirror and an external ring could be used to induce
the required curvature to realize new adaptive lens for optical aberration
correction. Recently, thermally-actuated deformable mirror on this principle
based, was proposed and prototyped. Although the feasibility and utility of
such innovative lens was demonstrated, no comprehensive theory was developed to
describe mirror behaviour and predict their curvature. Nowadays, the use of
approximated numerical approach, such as the finite element method, is the only
way to study the interaction between biased and interference fitted bodies. The
paper aims to give the theoretical background for the correct design of
adaptive lens actuated by interference fitting. A new formulation for the
curvature prediction is proposed and compared with finite element analysis and
available experimental measurements.
