Research On Design Method And Synthesis Characteristic For Two Degrees Of Freedom Of The Flexible Hinge-bar Mechanisms

Compliant mechanisms as an important branch of modern mechanisms, have become theresearch focus for many scholars. Compliant mechanism have no friction, no clearance, littlenoise and many other advantages, it can meet the requirements of modern mechanical.Compliant mechanisms have been widely used in micro-electromechanical systems (MEMS),aerospace, biomedical and many other high-tech fields. Compliant mechanisms design theoryand methods are not mature enough yet to be perfected. At present, many scholars haveresearched on the design methods, dynamic, optimal design for the four-bar flexible hingemechanisms. But relatively few research on the two degrees of freedom of the flexiblehinge-bar mechanisms. Two degrees of freedom of the flexible hinge-bar mechanisms is thebasis of the three degrees of freedom of flexible hinge mechanisms and other flexible spacemechanisms. The result of this paper provides some theoretical support for the further studyon other more complex compliant mechanisms.This paper have chosen the bar linkage as a structural unit of the two degrees of freedomcompliant mechanism as the main object of study, focus on the design method, dynamics,reliability and optimal design of the two degrees of freedom of the flexible hinge-barmechanisms.Firstly, flexible hinge is one of the four basic elements of compliant mechanisms, and isthe most important part of compliant mechanisms, and determines the special behavior ofwhole compliant mechanisms. Therefore, this paper studies on flexibility, precisioncharacteristics and the maximum stress near the notch of three kinds of flexible hinge.Simulation experiment is also processed on precision characteristics and the maximum stressnear the notch, precision characteristics and the maximum stress near the notch with variation between the structural parameters of flexible hinge is gained, and theoretical analysis of valueand simulation data is compared, and it proves the accuracy of the theoretical derivation.Secondly, this paper research on design method of three kinds of flexible hinge-barmechanisms, first proposed the two degrees of freedom of the flexible hinge six-barmechanisms. The research methods used by the three kinds of flexible hinge-bar mechanismsis basically the same: firstly, pseudo-rigid body model of the compliant mechanisms is created,according to the principle of virtual work. And draw the design of the universal formula; thenthe imitate-compliant-body model is created, which is on the basis of pseudo-rigid bodymodel. Finally, simulation experiment of the two degrees of freedom flexible hinge six-barmechanisms is also processed. And the simulation result and the theoretical computationresults are contrasted.Again, this paper researches the synthetic characteristics of the flexible hinge-barmechanisms the integrated nature of the flexible bar linkage. It researches on the dynamicscharacteristics of three mechanisms. It focuses on the two degrees of freedom of the flexiblehinge five-bar mechanisms, the method of calculation of natural frequency is gained. Andsimulation research is also processed on the mechanisms, natural frequency andfrequency-amplitude characteristic under multiple vibration modeis is also gained. It firstlyresearches the conclusion and summary of basic theory when involves reliability.Then itresearches on the example and simulation of two degrees of freedom of the flexible hingefive-bar mechanisms. It researches the number of simulation, average load and average widthwhich impact on reliability, and simulation data is plotted as a curve, variation law is obtainedbetween the four.Finally, optimal design research is also processed. The mathematical model of theoptimal design, which pursuit the performance optimization and pursuit the least value ofmass, is established. The solution of mathematical models of optimal design is obtained.