  A topology synthesis approach to design 2D Contact-aided Compliant Mechanisms
(CCMs) to trace output paths with three or more kinks is presented. Synthesis
process uses three different types of external, rigid contact surfaces:
circular, elliptical and rectangular: which in combination, offer intricate
local curvatures that CCMs can benefit from, to deliver desired, complex output
characteristics. A network of line elements is employed to generate topologies.
A set of circular subregions is laid over this network, and external contact
surfaces are generated within each subregion. Both, discrete and continuous
design variables are employed: the former set controls the CCM topology,
appearance and type of external contact surfaces, whereas the latter set
governs shapes and sizes of the CCM constituents, and sizes of contact
surfaces. All contact types are permitted with contact modeling made
significantly easier through identification of outer and inner loops. Line
topologies are fleshed out via a user-defined number of quadrilateral elements
along lateral and longitudinal directions. Candidate CCM designs are carefully
preprocessed before analysis via a commercial software and evolution using a
stochastic search. The process is exemplified via a contact-aided, 3-kink
mechanical switch which is thoroughly analysed in presence of friction and
wear.

Computational Engineering, Finance, and Science