考虑随机设计变量情形下的柔性铰链疲劳可靠性分析

Consider random design variables case of flexible hinge fatigue reliability analysis

由于柔顺机构传统可靠性分析方法并未考虑设计变量的随机波动性,使得可靠性分析存在操作性不强、精度不高的问题。引入可以有效处理随机设计变量的有限元概率设计新方法,将柔顺机构的几何尺寸、工作载荷和疲劳极限等参数视为随机设计变量,根据应力-强度干涉理论,构建极限状态函数,采用蒙特卡罗方法抽样计算可靠度。以直梁圆角型柔性铰链为实例进行可靠性分析,计算出当置信度为95%时,该柔性铰链的可靠度为99.26%,然后在此基础上对该类铰链的可靠性增长设计策略进行了讨论并给出建议。实例表明:该方法对柔性铰链的可靠性分析具有一定工程应用价值。

As compliant mechanism traditional reliability analysis without considering the design variables random dispersion that made reliability analyzing is not accuracy and work interoperabilityis not strong. Introduced the new method of finite element probability design that could effectively deal with stochastic volatility variable. The geometry dimensions, load and fatigue limit parameter were taken as random variables to the established compliant mechanism model. According to stress - strength interfer- ence theory, the limit state function was created. The Monte Carlo method was calculated reliability. Then take the straight beam fillet flexible hinge as an example for reliability analysis, at the confidence level of 95% , the reliability of the flexible hinge is 99.26% and on the basis of reliability growth of design strategies are discussed and suggestions. The results show that the new method has certain engineering application value.