机械模糊可靠性设计理论研究与应用

【作者】 安宗文；

【导师】 黄建龙；

【作者基本信息】 兰州理工大学 ， 机械设计及理论， 2003， 硕士

【摘要】 随着科学技术的发展，机械产品的可靠性越来越为世界各国所重视。可靠性是机械产品一项重要的质量评价指标，可靠性水平的高低直接关系到产品的竞争能力。铝锭铸造机组是生产普通重熔用铝锭的关键设备之一，机组可靠性的高低直接关系到企业大规模生产的效率，关系到企业参与市场竞争的能力。本文就机械模糊可靠性设计理论进行了初步研究，并结合铝锭铸造机传动系统进行了实际应用。 论文第一部分以模糊数学和常规可靠性设计理论为基础，将模糊数学的基本原理和常规可靠设计的基本思想有机融合，对机械模糊可靠性设计的基本原理和方法作了的探索和研究。提出基于“零件处于模糊安全状态隶属度”的模糊可靠性设计准则，并进一步对应力和强度分别为模糊随机变量时机械零件模糊可靠性设计的方法作了理论推导。同时，根据模糊数学中线性模糊数的代数运算法则推导出故障树分析中各种模糊逻辑门算子的数学表达式，基本构建了机械模糊可靠性设计的理论框架。 论文第二部分将上述理论应用于铝锭铸造机传动系统可靠性的分析，对输送链非正常失效的原因作了定性分析，得出引起输送链非正常失效的主要原因为链节联接牢固度不足。在此基础上，利用常规可靠性设计理论对滚子输送链联接牢固度的可靠性进行了优化设计，得出链节过盈联接最佳过盈量的参考数据。最后，根据铸造机实际运行状况建立了其传动系统故障树，并对故障树进行了模糊分析，得出传动系统可靠度的参考数据。上述结论可用于铸造机设计的进一步完善和改进。更多还原

【Abstract】 With the development of the science and technology, the reliability of mechanical products is paid more and more attention in the wide world recently. The reliability is an important quality index in mechanical products, and its level is of vital importance to the competitive power of the products. The aluminum ingot machine is one of the key equipments in producing of the common remelting aluminum ingot, and its reliability affects directly on the productivity and competitive power for market of an enterprise. The theory of mechanical fuzzy reliability design is studied and applied in this thesis.Based on the basic principle of the fuzzy mathematics and theory of the general reliability design, the fundamental principle and method of the mechanical fuzzy reliability design are investigated and studied through integrating the two ideologies in the first part of this thesis. A rule of fuzzy reliability design based on "component’s membership of the fuzzy safety state" is presented, furthermore, the method of fuzzy reliability design for machinery component is derived when stress and strength is respectively fuzzy random variable. Meanwhile, the mathematical operators of fuzzy logic gates in fault tree analysis are derived according to the operation rule of the linear fuzzy number. Finally, the theory scheme of mechanical fuzzy reliability design is set up basically.The second part of this thesis analyzes the reliability of the drive system of aluminum ingot machine by use of above theoretic results. Firstly, the qualitative analysis for the abnormal failure reason of conveyor chains is given, and that the main reason lead to failure is the lack of fastness of link joint is obtained. Furthermore, the reliability for joint fastness in roller chains for conveyors is optimized by using the general reliability design theory, and the optimum magnitude of interference of link joint is obtained. Finally, based on its running state, the fault tree of the drive system of aluminum ingot machine is established and analyzed fuzzily, and its reliability datum is obtained. Above results will be helpful to improve the aluminum ingot machine.更多还原