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转子系统的不确定性非参数动力学建模及其特性研究

发布时间:2018-10-19 11:15
【摘要】:转子系统是国家工业体系中重要设备的核心组成部分之一,在电力、航空、石化、机械等领域内有了广泛的应用,与此同时转子动力学也逐渐形成了一个相对完整的理论体系,对旋转设备的设计、实验、应用等提供了重要支撑。但是,由于随机不确定性因素在工程应用中不可避免地存在,会造成旋转机械在工作运行时出现振幅超标、故障频发等现象,而目前关于不确定性转子系统方面的研究成果屈指可数,急需开展转子系统在不确定性情形下的动力学特性研究工作。论文结合国家高技术研究发展计划(863)项目(编号:2008AA04Z410),国家自然科学基金项目(编号:11172260),开展了转子系统的随机不确定性非参数动力学建模与特性研究,为保证旋转机械安全稳定地运行提供理论支撑。论文主要研究了一种面向Jeffcott转子的非参数建模方法,建立了含随机不确定性的动力学振动模型,分析了其在圆盘偏置、不平衡、随机激励等情形下的动力学响应特性;提出了一种改进的含随机不确定性的密封转子动态参数算法;研究了故障转子系统在随机不确定性情形下的动力学特性,得到了故障转子的典型非线性特征;提出了一种基于非参数建模与谱密度分析相结合的转子系统可靠性算法,研究工作进一步丰富了转子动力学理论,为揭示工程中旋转机械产生振动、故障的原因提供手段与依据。论文的主要研究内容和成果有:(1)研究针对转子系统的随机不确定性非参数建模法,分析其响应特性。针对转子系统随机不确定性影响作用,给出了一种动力学响应对随机不确定性因素的灵敏度算法,提出了一种针对Jeffcott转子系统的随机不确定性非参数建模法,构建了包含参数不确定性与模型不确定性的转子系统不确定性动力学模型,分析了随机不确定性对转子系统临界转速的影响以及对系统响应的作用规律。研究发现随机不确定性会改变系统临界转速,对系统的振动响应也有明显的增大作用,研究成果是论文研究内容的基础,为后续研究工作提供理论依据。(2)研究随机不确定性因素影响下密封转子的动力系数算法。针对密封转子系统受到随机不确定性因素作用的情况,提出了根据流场内的随机不确定性特点采用有界噪声作用到转子系统模型中形成随机激励,以及利用有界噪声因素与椭圆形轴心轨迹相结合形成相应的不确定性轨迹,推导了转子系统的随机不确定性扰动间隙、密封腔室的参数以及作用于转子上的密封力计算方法,形成了一种随机不确定性密封转子的动力系数计算方法,分析了随机不确定性因素对密封转子系统动力系数的影响规律。数值模拟表明随机不确定性会使密封转子动力系数的计算结果产生较大波动,论证了随机不确定性因素对转子动力学产生的作用以及验证了非参数建模方法的必要性。(3)研究了随机不确定性转子系统故障状态下的动力学响应特性。分别建立了不对中、气流激振、碰磨等故障转子系统的随机不确定性模型,分析了转子系统在随机不确定性因素作用下的非线性动力学特性,提出了一种改进的、随机不确定扰动作用下转子系统响应特征的去扰处理方法,得到了清晰的系统混沌响应特征,搭建了具有典型代表的转子实验系统进行验证。仿真结果直观地揭示了转子系统在不同故障下的非线性特征随不确定性强度的变化情况,说明了改进的去扰处理算法的有效性,研究内容是在随机不确定性转子系统非参数建模的基础上与故障转子相结合,丰富了不确定性转子系统动力学理论,为从理论向实践应用转变打下基础。(4)研究了随机不确定性转子系统振动响应的可靠性算法。针对不确定性转子系统运行的可靠性问题,提出了一种基于非参数建模与谱密度分析相结合的可靠性指标计算方法,应用非参数建模法建立了转子系统的随机不确定性动力学振动模型,利用谱密度分析法推导了系统响应的特征参数,通过Edgeworth级数标准化方法归一化处理得到了可靠性指标,数值分析验证了此方法的适用性,为不确定性转子系统提供运行状态稳定性、可靠性的判断方法,为实际应用提供有力工具。
[Abstract]:The rotor system is one of the core components of the important equipment in the national industrial system. In the field of power, aviation, petrochemical, machinery and so on, the rotor system has been widely used in the field of electric power, aviation, petrochemical, machinery and so on. At the same time, the rotor dynamics gradually form a relatively complete theoretical system, the design and experiment of rotating equipment, the application and the like provide important support. However, due to the inevitable existence of random uncertainty factors in engineering application, the phenomena such as excessive amplitude and frequent failure of rotating machinery during operation are caused, and the present research results on uncertain rotor systems are numbered. It is urgent to carry out the research work of the dynamic characteristics of the rotor system in the uncertain situation. Based on the national high-tech research and development plan (863) project (No.: 2008AA04Z410), NSFC's project (No.: 111722260), the random uncertainty non-parametric dynamic modeling and characteristic research of the rotor system are carried out. Theoretical support is provided to ensure safe and stable operation of rotating machinery. In this paper, a non-parametric modeling method for Jeffcott rotor is studied, a dynamic vibration model with stochastic uncertainty is established, and its dynamic response characteristics are analyzed under the condition of disk bias, unbalance and random excitation. An improved dynamic parameter algorithm of sealed rotor with stochastic uncertainty is proposed. The dynamic characteristics of the fault rotor system under stochastic uncertainty are studied, and the typical nonlinear characteristics of the fault rotor are obtained. A reliability algorithm of rotor system based on non-parametric modeling and spectral density analysis is presented. The research work further enriches the theory of rotor dynamics, and provides means and basis for revealing the cause of vibration and failure in rotating machinery in engineering. The main contents and achievements of the thesis are: (1) Study the stochastic uncertainty non-parametric modeling method aiming at the rotor system, and analyze its response characteristics. Aiming at the influence of stochastic uncertainty of rotor system, a sensitivity algorithm for dynamic response to stochastic uncertainty factors is given, and a stochastic uncertainty non-parametric modeling method for Jeffcott rotor system is proposed. The dynamic model of rotor system with parameter uncertainty and model uncertainty is constructed. The influence of stochastic uncertainty on the critical speed of rotor system and the law of system response are analyzed. It is found that the random uncertainty can change the critical speed of the system, and the vibration response of the system also has an obvious increase. The research results are the basis of the research content of the paper and provide the theoretical basis for the follow-up research work. (2) studying the dynamic coefficient algorithm of the sealed rotor under the influence of stochastic uncertainty factors. aiming at the condition that the sealed rotor system is subjected to random uncertainty factors, a random excitation is formed in a rotor system model by adopting boundary noise according to the characteristics of random uncertainty in the flow field, and combining the boundary noise factor and the elliptical axis locus to form a corresponding uncertainty track, and the random uncertainty disturbance clearance of the rotor system, the parameters of the sealing chamber and the calculation method of the sealing force acting on the rotor are deduced, A dynamic coefficient calculation method of stochastic uncertain sealed rotor is formed, and the influence of stochastic uncertainty factors on dynamic coefficient of sealed rotor system is analyzed. The numerical simulation shows that the stochastic uncertainty results in larger fluctuation of the calculation result of the dynamic coefficient of the sealed rotor. The effect of stochastic uncertainty factors on rotor dynamics and the necessity of non-parametric modeling method are proved. (3) The dynamic response characteristics of a stochastic uncertain rotor system fault condition were studied. In this paper, a stochastic uncertainty model for fault rotor systems such as medium, gas-flow excitation and collision-grinding is established. The nonlinear dynamics of the rotor system under stochastic uncertainty are analyzed, and an improved method is proposed. The disturbance processing method of rotor system response characteristics under disturbance is not determined at random, a clear system response characteristic is obtained, and a rotor experimental system with typical representative is constructed. The simulation results show that the nonlinear characteristics of the rotor system under different faults vary with the strength of the uncertainty, the effectiveness of the improved de-disturbance processing algorithm is described, and the research contents are combined with the fault rotor on the basis of the non-parametric modeling of the stochastic uncertainty rotor system. The dynamic theory of uncertain rotor system is enriched, which lays a foundation for the transformation from theory to practical application. (4) The reliability algorithm of vibration response of stochastic uncertain rotor system is studied. Aiming at the reliability problem of uncertainty rotor system operation, a reliability index calculation method based on non-parametric modeling and spectral density analysis is put forward, and a stochastic uncertainty dynamic vibration model of the rotor system is established by using the non-parametric modeling method. The characteristic parameters of the system response are derived by the spectral density analysis method, and the reliability index is obtained by the normalization of the EdgePoint series normalization method. The applicability of the method is verified, and the method for judging the stability and the reliability of the operation state for the uncertain rotor system is provided. Provide powerful tools for practical applications.
【学位授予单位】:浙江大学
【学位级别】:博士
【学位授予年份】:2016
【分类号】:TH113

【参考文献】

相关期刊论文 前10条

1 张义民;曹辉;王昊;杨周;;基于主轴动态响应的车削加工精度可靠性及灵敏度分析[J];振动与冲击;2015年23期

2 朱文龙;周建中;夏鑫;李超顺;;基于水电机组运行工况的水轮机压力脉动诊断策略[J];振动与冲击;2015年08期

3 梁庆姣;刘吉臻;薛彦广;闫姝;曾德良;;超超临界机组的非线性模型及动态特性研究[J];动力工程学报;2012年02期

4 邢亚捷;何玉宝;;超临界汽轮机推力轴承磨损原因分析与处理[J];安徽电力;2011年04期

5 王晓军;杨海峰;邱志平;覃梓轩;;基于非概率集合可靠性的结构优化设计[J];计算力学学报;2011年06期

6 吴文健;童小忠;应光耀;李卫军;;单支撑超超临界1000 MW汽轮发电机组振动诊断及处理[J];浙江电力;2011年10期

7 孙文彩;杨自春;;区间参数结构可靠性分析新模型[J];海军工程大学学报;2011年03期

8 牟法海;李春玉;张林茂;王文营;高翔;张伟江;唐广通;;600MW超临界汽轮发电机组振动异常的原因分析及处理措施[J];河北电力技术;2011年02期

9 韩志杰;王璋奇;;基于非概率区间模型的可靠性分析与优化[J];中国机械工程;2011年06期

10 乔心州;仇原鹰;盛英;;含模糊变量和区间变量的结构可靠性优化设计方法[J];计算力学学报;2010年03期

相关会议论文 前3条

1 王跃华;甘春标;杨世锡;;Jeffcott转子不确定动力学建模与故障特征识别[A];第九届全国动力学与控制学术会议会议手册[C];2012年

2 甘春标;杨世锡;王跃华;丁长涛;;不确定性理论与方法及其在机械动力学分析中的初步应用[A];第九届全国动力学与控制学术会议会议手册[C];2012年

3 甘春标;丁长涛;杨世锡;;平面双足机器人轨迹规划中参数不确定性动力学模型研究[A];第九届全国动力学与控制学术会议会议手册[C];2012年

相关博士学位论文 前3条

1 沈小要;超超临界汽轮机组转子系统振动特性及若干故障转子非线性特性的研究[D];上海交通大学;2007年

2 梁震涛;不确定性结构的分析方法研究[D];西安电子科技大学;2007年

3 王坤;大型汽轮机转子寿命问题研究[D];华中科技大学;2004年

相关硕士学位论文 前4条

1 郭晶晶;国产600MW超临界汽轮机转子寿命研究[D];华北电力大学(北京);2011年

2 刘s,

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