运动机构双重随机可靠性模型及其求解方法

Reliability Analysis for Mechanism Considering Uncertainty of Statistical Parameters of Distribution Functions

研究运动机构输入参数的双重随机特性,并针对机构运动精度失效模式,基于应力-强度干涉理论,建立运动机构双重随机可靠性模型和评估指标——失效概率的数学期望,推导了失效概率数学期望基于双重重要抽样法的求解公式。以偏心曲柄滑块机构和牛头刨床主运动机构为例,验证了提出的可靠性模型及求解方法的合理性和实用性。

The reliability assessment is studied for the mechanisms when the statistical parameters of the distribution functions can not be determined accurately due to incomplete information. Firstly, consider ing the uncertainty of the parameters for the mechanism, a reliability model is constructed. Then taking failure mode of kinematic accuracy for example, reliability assessment indicator is deduced by using double stochastic reliability model. The solving formula of the expecation of failure probability is given baesd on double importance sampling method. By applying double stochastic reliability model to slider crank mechanism and shaper＇s main motion mechanism, the rationality and practicability of the pro posed method are validated.