论文部分内容阅读
针对可靠性分析中不确定参数的分布类型难以精确获得的情况,采用非概率方法进行可靠性分析.用区间模型描述不确定参数,结合应力-强度非概率集合干涉理论,建立了不同情况下的非概率可靠性指标,分析了某传动轴在概率模型和区间模型下的可靠性指标以及不确定参数的离差与非概率可靠性之间的关系.结果表明:当传动轴外径为50mm时,二者均认为结构可靠,外径为48mm时,概率可靠度为0.999 803,非概率可靠度为0.982 110,两种结论是一致的,但非概率方法更保守,同时传动轴的非概率可靠度随着不确定参数离差的增加而逐渐减低,其中强度离差对可靠度影响最大,扭矩离差最小.说明增加壁厚以及减小不确定参数的离差可以提高传动轴的可靠度,表明非概率可靠性分析方法的工程适用性.
Aiming at the situation that the distribution types of uncertain parameters in the reliability analysis are difficult to obtain accurately, the non-probabilistic method is used to analyze the reliability.Using the interval model to describe the uncertain parameters and the stress-intensity non-probability set interference theory, Non-probabilistic reliability index, the reliability index of a propeller shaft under probabilistic model and interval model and the relationship between the uncertainty of unspecified parameters and non-probabilistic reliability are analyzed.The results show that when the outer diameter of propeller shaft is 50mm , Both of which are considered as reliable structures. When the outer diameter is 48mm, the probability reliability is 0.999 803 and the non-probability reliability is 0.982 110. The two conclusions are consistent, but the non-probability method is more conservative and the drive shaft is non-probabilistic Degree decreases with the increase of the uncertainty parameter, in which the strength deviation has the greatest influence on the reliability and the torque deviation is the smallest, which shows that increasing the wall thickness and reducing the dispersion of the uncertain parameters can improve the reliability of the transmission shaft, It shows the engineering applicability of non-probabilistic reliability analysis method.