柔顺机构靠弹性变形来传递运动或力,因而疲劳是其主要失效模式,但其疲劳性能以及抗疲劳设计方法仍有待进一步研究.文中结合笔者及其课题组的研究成果,介绍了柔顺机构的主要设计方法,在综述名义应力法、局部应力应变法和应力场强法3种疲劳寿命预测方法的基础上,阐述了直圆型和叶型柔性铰链的疲劳寿命预测模型及尺寸参数对铰链疲劳寿命的影响,总结了柔顺机构疲劳可靠性的分析和优化设计方法,以及基于特征参数分解的柔顺机构损伤识别方法,并指出了柔顺机构疲劳可靠性及损伤识别的未来研究方向.
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 identi- fication 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.