Abstract:

As compliant mechanisms transfer motion and force relying on elastic deformation,fatigue becomes the main failure mode of the mechanisms. Therefore,further researches on the fatigue properties and the design against fatigue are necessary for compliant mechanisms. In this paper,based on the research results of the authors and their team,the main design methods of compliant mechanisms are briefly described. Then,through a review of the three main fatigue life prediction approaches,namely,the nominal stress approach, the local stress-strain approach and the stress field intensity approach,the authors introduce the models of fatigue life prediction for right circular flexure hinges and leaf flexure hinges,with emphasis on the effects of size parameters of hinges on the fatigue life. Moreover,several analysis and optimization design methods of compliant mechanisms,as well as the damage identification approach based on the eigenparameter decomposition,are included in this article. The research orientation of the fatigue reliability and damage identification of compliant mechanisms is finally pointed out.

Key words: compliant mechanism, fatigue life prediction, fatigue reliability, damage identification