混合不确定性下的重型数控机床主轴系统可靠性建模与分析方法研究
发布时间：2018-12-12 23:22
【摘要】：重型数控机床肩负着众多关系国民经济与国防安全的行业产品及关键零部件的加工制造,其质量、性能和技术水平是衡量一个国家工业化水平和综合经济实力的重要标志。国产重型数控机床经过多年的发展已取得一定成就,但由于国产重型数控机床科技创新不足,基础实验条件缺乏,高级人才匮乏,尖端核心技术尚未突破,其在使用过程中不断暴露出早期故障频发、质量稳定性差、维护成本高等问题,这些问题给重型数控机床用户带来系列困难和挑战,并直接导致我国国产重型数控机床可靠性差、产品附加值低、产业化能力弱、国际竞争力不强等恶劣局面。现有数控机床可靠性技术体系多是针对中小型数控机床构建,针对重型数控机床可靠性技术的研究尚未深入开展。由于重型数控机床在结构形式、加工任务等方面与中小型数控机床大有不同,现有可靠性技术不能直接应用。因此,亟需针对重型数控机床结构功能特点,开展重型数控机床可靠性技术体系研究。可靠性建模与分析是重型数控机床可靠性技术体系的关键组成部分。重型数控机床可靠性建模与分析是在综合研究机床可靠性影响因素和可靠性数据特征的条件下,以典型系统可靠性模型为基础,结合重型数控机床结构功能特点,建立数学模型来对其可靠性进行分析和评定的过程。相对于普通数控机床,重型数控机床可靠性建模与分析具有系统结构复杂、整机及关键零部件样本少、试验数据不足、信息不全、可靠性数据类型多样、故障机理复杂且故障相关等难点。针对以上重型数控机床可靠性研究难点,本文主要开展以下研究工作:(1)以重型数控机床主轴为研究对象,分析了影响重型数控机床主轴可靠性的各种不确定性因素及现有不确定性量化方法的局限性,构建了基于不精确概率理论的混合不确定性统一量化框架。在混合不确定性统一量化框架下,基于应力-强度干涉理论,提出了针对机床零部件的不精确结构可靠性建模一般方法。以某重型数控落地铣镗床铣轴为例,对铣轴的多个失效模式进行了不精确结构可靠性分析、建模与计算。(2)在混合不确定性统一量化框架下,针对机床零部件,提出了考虑多失效模式相关性的结构可靠性建模与分析方法。失效模式多样且失效相关是机床零部件失效的普遍特征,现有文献对失效相关性的研究基于大量故障统计数据,未考虑数据不足情况,这与重型数控机床实际数据特征不符。针对该问题,本文引入表征相关性的Copula函数于不精确结构可靠性模型中,提出了考虑多失效模式相关的不精确结构可靠性改进模型,并将该改进模型应用到铣轴可靠性建模与分析中,实现了铣轴多失效模式相关性分析与计算,通过与失效独立条件下的计算结果进行对比,验证了工程实际中考虑失效相关的必要性。(3)重型数控机床整机及其子系统的可靠性仍受到混合不确定性因素影响,且各子系统失效相互关联,本文综合考虑以上两个因素,以零部件混合不确定性统一量化、零部件不精确结构可靠性建模、零部件失效相关性分析为基础,提出了同时考虑混合不确定性和失效相关性的系统可靠性建模与分析方法,并分别建立了典型系统不精确可靠性模型、基于故障树分析的系统不精确可靠性模型;重型数控机床主轴系统组成零部件众多,对各个零部件均进行故障相关性分析,工作量巨大,本文借助于DEMATEL方法,分析了主轴系统各个零部件的故障重要程度、零部件故障关联程度,以铣轴组件为研究重点,完成了铣轴组件的不精确可靠性建模与分析。(4)重型数控机床在设计研制阶段经过“设计-试验-改进-再设计-再试验”、“研制-测试-改进-再研制-再测试”的重复过程,其可靠度不断增长,前一增长阶段的可靠性信息可作为下一阶段可靠性增长的评定依据,考虑到数据不足时先验分布无法精确确定,本文采用不精确Dirichlet先验分布族表征先验信息,建立了系统不精确可靠性增长模型,并将该模型应用到铣轴组件的固有可靠性评定中;考虑到使用可靠性与固有可靠性的耦合性,本文以固有可靠性信息为不精确先验信息,以使用可靠性评定为目标,建立了使用可靠性评估模型,实现了铣轴组件使用可靠性的评定。
[Abstract]:The heavy-duty CNC machine tool bears many industrial products and key parts of national economy and national defense safety. The quality, performance and technical level of the heavy-duty numerical control machine are the important marks to measure the industrialization level and the comprehensive economic strength of a country. With the development of the domestic heavy-duty numerical control machine for many years, some achievements have been made, but due to the insufficient scientific and technological innovation of the domestic heavy-duty numerical control machine, the lack of the basic experimental conditions, the shortage of the high-level talents, the core technology of the tip has not been broken, and the frequent occurrence of the early faults in the use process is constantly exposed, The problems of poor quality stability and high maintenance cost bring the series of difficulties and challenges to the users of heavy-duty CNC machine tools, and directly lead to the poor reliability of the domestic heavy-duty CNC machine tools, the low added value of the products, the weak industrialization ability and the non-strong international competitiveness. The reliability technology system of the present numerical control machine tool is mainly for small and medium-sized numerical control machine tools, and the research on the reliability technology of heavy-duty numerical control machine tools has not been carried out yet. Because the heavy-duty numerical control machine tool is different from the small and medium-sized numerical control machine tool in the aspect of the structure form, the processing task and the like, the existing reliability technology cannot be directly applied. Therefore, it is urgent to study the reliability technology system of heavy-duty NC machine tools for the features of the structure of heavy-duty NC machine tools. Reliability modeling and analysis are the key components of the reliability technology system of heavy-duty NC machine tools. The reliability modeling and analysis of the heavy-duty numerical control machine tool is based on the typical system reliability model under the condition that the reliability influence factors and the reliability data characteristics of the machine tool are comprehensively studied, and the structure function characteristics of the heavy-duty numerical control machine tool are combined. A mathematical model is established to analyze and evaluate its reliability. Compared with the general numerical control machine, the reliability modeling and analysis of the heavy-duty numerical control machine tool has the difficulties of complex system structure, few samples of the whole machine and the key parts, insufficient data of the test data, various reliability data types, complex fault mechanism, and the like. In view of the difficulties in the reliability research of the above heavy-duty numerical control machine tools, this paper mainly carries out the following research work: (1) taking the main shaft of the heavy-duty numerical control machine as the research object, analyzing the various uncertainty factors which influence the reliability of the main shaft of the heavy-duty numerical control machine and the limitation of the existing uncertainty quantization method, A unified quantitative framework for mixed uncertainty based on the theory of uncertain probability is constructed. In this paper, based on the theory of stress-intensity interference, a general approach to the reliability modeling of the non-precise structure of the parts of the machine tool is put forward based on the theory of stress-intensity interference. In this paper, the reliability analysis, modeling and calculation of the multiple failure modes of a heavy-duty numerical control landing gear bed are carried out in this paper. (2) The structural reliability modeling and analysis method considering the correlation of multi-failure modes is put forward under the unified quantitative framework of mixed uncertainty. The failure mode is multiple and the failure is related to the general feature of the failure of the machine tool parts. The research of the failure correlation is based on a large number of fault statistics, and the data deficiency is not taken into account, which is not in conformity with the actual data characteristics of the heavy-duty numerical control machine. In order to solve this problem, this paper introduces a correlation-based Copula function in the uncertain structural reliability model, and puts forward an improved model of the non-precise structural reliability considering the multi-failure mode, and applies the improved model to the reliability modeling and analysis of the eccentric shaft. In this paper, the correlation analysis and calculation of multi-failure mode are realized, and the necessity of considering failure in engineering practice is verified by comparing with the calculation results under the failure independent condition. (3) The reliability of the whole machine and its sub-system of the heavy-duty numerical control machine is still affected by the mixed uncertainty factors, and the failure of each subsystem is related to each other. Based on the analysis of component failure correlation, a system reliability modeling and analysis method considering the mixed uncertainty and the failure correlation is put forward, and a typical system uncertainty reliability model is established, and the system uncertainty reliability model based on the fault tree analysis is established. The main shaft system of the heavy-duty numerical control machine has a large number of components, and the fault-related analysis is carried out for each component, and the workload is great. In this paper, by means of the DEATEL method, the fault importance, the degree of the fault of the parts and components of the main shaft system are analyzed. In this paper, the precise reliability modeling and analysis of the shaft assembly is completed with the focus of the shaft assembly. (4) The reliability of the heavy-duty numerical control machine in the design and development stage through the 鈥淒esign-Test-Improvement-Redesign-Retest鈥，
本文编号：2375425
[Abstract]:The heavy-duty CNC machine tool bears many industrial products and key parts of national economy and national defense safety. The quality, performance and technical level of the heavy-duty numerical control machine are the important marks to measure the industrialization level and the comprehensive economic strength of a country. With the development of the domestic heavy-duty numerical control machine for many years, some achievements have been made, but due to the insufficient scientific and technological innovation of the domestic heavy-duty numerical control machine, the lack of the basic experimental conditions, the shortage of the high-level talents, the core technology of the tip has not been broken, and the frequent occurrence of the early faults in the use process is constantly exposed, The problems of poor quality stability and high maintenance cost bring the series of difficulties and challenges to the users of heavy-duty CNC machine tools, and directly lead to the poor reliability of the domestic heavy-duty CNC machine tools, the low added value of the products, the weak industrialization ability and the non-strong international competitiveness. The reliability technology system of the present numerical control machine tool is mainly for small and medium-sized numerical control machine tools, and the research on the reliability technology of heavy-duty numerical control machine tools has not been carried out yet. Because the heavy-duty numerical control machine tool is different from the small and medium-sized numerical control machine tool in the aspect of the structure form, the processing task and the like, the existing reliability technology cannot be directly applied. Therefore, it is urgent to study the reliability technology system of heavy-duty NC machine tools for the features of the structure of heavy-duty NC machine tools. Reliability modeling and analysis are the key components of the reliability technology system of heavy-duty NC machine tools. The reliability modeling and analysis of the heavy-duty numerical control machine tool is based on the typical system reliability model under the condition that the reliability influence factors and the reliability data characteristics of the machine tool are comprehensively studied, and the structure function characteristics of the heavy-duty numerical control machine tool are combined. A mathematical model is established to analyze and evaluate its reliability. Compared with the general numerical control machine, the reliability modeling and analysis of the heavy-duty numerical control machine tool has the difficulties of complex system structure, few samples of the whole machine and the key parts, insufficient data of the test data, various reliability data types, complex fault mechanism, and the like. In view of the difficulties in the reliability research of the above heavy-duty numerical control machine tools, this paper mainly carries out the following research work: (1) taking the main shaft of the heavy-duty numerical control machine as the research object, analyzing the various uncertainty factors which influence the reliability of the main shaft of the heavy-duty numerical control machine and the limitation of the existing uncertainty quantization method, A unified quantitative framework for mixed uncertainty based on the theory of uncertain probability is constructed. In this paper, based on the theory of stress-intensity interference, a general approach to the reliability modeling of the non-precise structure of the parts of the machine tool is put forward based on the theory of stress-intensity interference. In this paper, the reliability analysis, modeling and calculation of the multiple failure modes of a heavy-duty numerical control landing gear bed are carried out in this paper. (2) The structural reliability modeling and analysis method considering the correlation of multi-failure modes is put forward under the unified quantitative framework of mixed uncertainty. The failure mode is multiple and the failure is related to the general feature of the failure of the machine tool parts. The research of the failure correlation is based on a large number of fault statistics, and the data deficiency is not taken into account, which is not in conformity with the actual data characteristics of the heavy-duty numerical control machine. In order to solve this problem, this paper introduces a correlation-based Copula function in the uncertain structural reliability model, and puts forward an improved model of the non-precise structural reliability considering the multi-failure mode, and applies the improved model to the reliability modeling and analysis of the eccentric shaft. In this paper, the correlation analysis and calculation of multi-failure mode are realized, and the necessity of considering failure in engineering practice is verified by comparing with the calculation results under the failure independent condition. (3) The reliability of the whole machine and its sub-system of the heavy-duty numerical control machine is still affected by the mixed uncertainty factors, and the failure of each subsystem is related to each other. Based on the analysis of component failure correlation, a system reliability modeling and analysis method considering the mixed uncertainty and the failure correlation is put forward, and a typical system uncertainty reliability model is established, and the system uncertainty reliability model based on the fault tree analysis is established. The main shaft system of the heavy-duty numerical control machine has a large number of components, and the fault-related analysis is carried out for each component, and the workload is great. In this paper, by means of the DEATEL method, the fault importance, the degree of the fault of the parts and components of the main shaft system are analyzed. In this paper, the precise reliability modeling and analysis of the shaft assembly is completed with the focus of the shaft assembly. (4) The reliability of the heavy-duty numerical control machine in the design and development stage through the 鈥淒esign-Test-Improvement-Redesign-Retest鈥，
本文编号：2375425
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