ABSTRACT
The finite-element technique, through several commercially available software programs, is a favorite tool for modeling and analyzing the behavior of compliant mechanisms. A few reasons for the preference given to the finite-element procedure in both industry and research or academia include the speed of analysis, wide choice of analysis types (static, modal, dynamic, thermal, and mixed/coupled-field are the basic modules currently incorporated in professional finite-element software), and direct interaction with related CAD tools that provide the geometry of oftentimes complex shapes or the relative (at least apparent) ease of use. Several levels of complexity for modeling and analyzing flexure-based compliant mechanisms are provided by the finite-element software codes. The most basic approach to a given application starts with a specified geometry that is utilized to perform the desired analysis in order to find the state of stress and deformation or the modal response, for instance. Because all the parameters are predetermined, the insight that can be gained by running a finite-element analysis is limited to the particular geometry that has originally been selected. Several CAD programs are currently designed to connect interactively with a finiteelement module and enable the parametric design or drawing of a part or subassembly. As a consequence, it is possible to quickly model and analyze more geometry configurations by simply changing the numerical values of the geometric parameters of interest, and the procedure this way actually becomes an optimization tool that performs a sequential search over the design subspace of interest. Most of the finite-element programs also have the capability of running a real optimization module based on a start design whose parameters are subsequently varied through algorithms that are internal to the software until the local optimum response is reached.
