Research On Statics, Dynamics, Fatigue Life And Reliability Of The Flexure Hinge

A flexure hinge consists of a flexible, slender region between two rigid parts that must undergo limited relative rotation in a mechanism. A flexure hinge can offer several advantages over classical rotation joints, such as no need for lubrication, no hysteresis, no friction losses, compactness, capacity to be utilized in small-scale applications, no assembly, and no required maintenance. The flexure hinges are employed in a lot of application, both civil and military, including navigation, manufacture, optics, bioengineering and so on. But the uses of the flexure hinges are restricted because of the mutative section which is difficult to analyze and design. The classical methods that only analyze statics of the simple flexure hinge based on the hypothesis of the small deformation are deficient. In fact, the analyses of dynamics, fatigue and reliability are very important to flexure hinge. In this paper, author analyzes the above questions of the single-axis flexure hinge in a certain extent. Firstly, the expression of a unit stiffness matrix of flexure hinges is obtained. Secondly, a flexure hinge is characterized by quantifying its rotation capacity, precision of rotation, level of stress. Thirdly, the problems of large deformation are investigated by using two different methods. Based on the static analysis, the dynamic analysis is done. The model of a single-axis flexure hinge is obtained. The method of vibration analysis is applied to research the free and forced response. In the procession of analysis of fatigue, the factors of affecting the flexure hinge's life are investigated and the flexure hinge's life is estimated by applying the method of stress field intensity. In the procession of analysis of reliability, the questions of the flexure hinge's reliability are put forward and analyzed using the method of stress-intensity and ANSYS soft. The analytical model predictions are confirmed by finite element simulation. Many computations are obtained by using MATLAB. In a word, not only many new questions of the flexure hinges are investigated, but also the analyzing and designing precision of the flexure hinges is improved. So it will be a help to the analysis and design of the flexure hinges and flexure-based compliant mechanisms.