A PROCEDURE FOR THE OPTIMAL SYNTHESIS OF PLANAR MECHANISMS BASED ON NONLINEAR POSITION PROBLEMS

The present paper describes a procedure for the optimal dimensional sy nthesis of mechanisms which is based on the solution of non-linear pos ition problems. Planar mechanisms are modelled very easily by means of finite elements of bi-hinged rod type. The judicious choice of constr aint conditions makes possible the solution of classical position prob lems: initial, finite-displacement, deformed and static-equilibrium pr oblems, as well as the main types of dimensional synthesis: path gener ation, functions, rigid body guidance, mixed, and multiple. A single s ynthesis error function applies to all these types, and moreover is ge neral since. it is valid for mechanisms of any configuration. This fun ction is based on the idea that the best mechanism for the given synth esis conditions is the one that least needs to be deformed when it is obliged to satisfy them exactly, to which end the elastic deformation of the elements is permitted. (C) 1997 by John Whey & Sons, Ltd.