Research On Design Of Plane Compliant Mechanisms

Compliant mechanisms (CM) can be defined as mechanisms that gain some or all of their motion due to the relative flexibility of their members. CM contain little or none of rigid-body counterparts. So, the design method of CM is greatly different from that of traditional rigid-body mechanisms and the design methodology for CM has not been established systemically till now. Because of many excellences of CM which the traditional rigid-body mechanisms do not have, they have been used widely in the field of aviation, space flight, MEMS (micro electronic mechanisms system), biological medicine and so on. For these reasons, the research on CM design has become one of hotspots in the field of mechanical design and theory recently. CM design is researched in this paper systemically, and main work and results are shown below.Based on the work done before, the paper summarizes the design method and theory for CM design. Large deflection function of beam and analysis are introduced, and the deflection result can be obtained by the numerical methods. For engineering application, a series of simplification of mathematic mode is presented, which is called as pseudo-rigid-body method, and can be applied easily. For the more, according to different load parameter, a process of the parameter determination of compliant mechanisms is proposed. A few examples are shown.Then, the principle of virtual work is used to derivate the equilibrium condition of CM. Following the conditions, two stable equilibrium positions for compliant four-bar mechanisms with one or two characteristic pivots are found with use of the energy function. Then, the effect of force on changing stable equilibrium situation of four-bar compliant mechanisms is discussed. At the same time, multi-stability compliant mechanisms are discussed. They can be structured by connecting twosimple compliant four-bar mechanisms in series. A method to compute force required to change the equilibrium position of compliant multi-stable mechanisms is presented also.With the direction of finite element analysis and topological optimization, we built up the mathematical model of optimum design of distributed compliance mechanisms, which is aimed at maximum rigidity. Then, with the language of MATLAB, we develop a program to solve the problem of maximization of rigid for CM design. We also study the method to design compliant mechanisms by maximization compliant. Design of compliant mechanisms with single input and single output is accomplished.