涡轮叶片干摩擦阻尼减振特性研究

发布时间：2018-03-23 00:02

本文选题：叶片　切入点：干摩擦　出处：《南京航空航天大学》2014年硕士论文　论文类型：学位论文

【摘要】：发动机故障有很多，，其中最常见的就是叶片的振动导致的故障，大约占到全部发动机故障的三分之一。通过干摩擦阻尼来减小叶片的振动不仅施行起来简单，而且效果显著，能够限制构件的应力水平，因此在航空发动机、电站汽轮机、燃气轮机等涡轮机上得到广泛的应用。深入研究叶片的振动特性以及其减振技术，尽可能的降低叶片的振动程度，具有极其重要的理论意义和工程实际意义。本文结合有限元分析方法，在建立三维干摩擦模型的基础上，编制叶片的振动响应分析程序，通过对各种叶片进行理论计算，分析每个参数对不同叶片振动特性的影响，并将对叶片的减振特性分析扩展到叶/盘结构的叶片模型上，充分考虑了盘片耦合对减振效果的影响。本文主要工作如下：（1）在二维整体—局部统一滑动模型的基础上，考虑法向振动对正压力的影响，引入动摩擦系数和静摩擦系数的概念，建立三维整体—局部统一滑动模型。（2）在对三维运动模型进行求解时，考虑摩擦力的非线性特征，采用新的干摩擦阻尼等效方案，将接触面之间的干摩擦力变换为新的等效阻尼及等效刚度，推导出新的等效刚度和等效阻尼的计算公式。（3）利用ANSYS软件的谐响应分析功能，结合VC++和APDL语言，编写了对应于不同类型叶片的振动响应分析程序，用简化的带缘板阻尼器叶片、300平行冠叶片和450锯齿冠叶片进行算例分析，分析正压力、外激励对减振效果的影响，得到其各自的干摩擦减振特性。（4）设计合理的振动响应实验方案，对300平行冠叶片和450锯齿冠叶片的干摩擦减振特性进行了实验分析，为理论计算提供实验参照依据。（5）应用针对循环对称结构在简谐激励作用下的振动响应的数学求解模型，编写锯齿冠叶片基于叶/盘结构的循环对称结构分析程序，对450锯齿冠叶片进行基于叶/盘结构的减振特性分析。
[Abstract]:There are many engine failures, among which the most common one is the fault caused by blade vibration, which accounts for about 1/3 of all engine failures. Reducing the vibration of blade by dry friction damping is not only simple, but also effective. It can limit the stress level of the components, so it is widely used in aero-engine, power plant steam turbine, gas turbine and so on. The vibration characteristics of the blade and its damping technology are studied in depth to reduce the vibration degree of the blade as much as possible. It is of great theoretical and practical significance. Based on the three-dimensional dry friction model and finite element analysis method, the vibration response analysis program of blade is compiled in this paper. Through theoretical calculation of various blades, the influence of each parameter on the vibration characteristics of different blades is analyzed. The analysis of the vibration absorption characteristics of the blade is extended to the blade model of the blade / disk structure, and the effect of disk coupling on the damping effect is fully considered. The main work of this paper is as follows:. 1) on the basis of two-dimensional global and local unified sliding model, considering the influence of normal vibration on normal pressure, the concepts of dynamic friction coefficient and static friction coefficient are introduced, and a three-dimensional integral and local unified sliding model is established. 2) considering the nonlinear characteristics of friction force, a new dry friction damping equivalent scheme is adopted to transform the dry friction force between contact surfaces into new equivalent damping and equivalent stiffness. A new formula for calculating equivalent stiffness and damping is derived. Using the harmonic response analysis function of ANSYS software and combining VC and APDL language, the program of vibration response analysis corresponding to different types of blades is compiled. The simplified blade with edge plate damper is used to analyze the parallel crown blade and 450 sawtooth crown blade. The effects of positive pressure and external excitation on the damping effect are analyzed and their dry friction characteristics are obtained. 4) A reasonable vibration response experimental scheme is designed. The dry friction vibration absorption characteristics of 300 parallel crown blades and 450 sawtooth crown blades are experimentally analyzed, which provides an experimental reference for theoretical calculation. In this paper, a mathematical solution model for the vibration response of cyclic symmetric structure under harmonic excitation is applied to compile a cyclic symmetric structure analysis program based on blade / disk structure. The vibration absorption characteristics of 450 sawtooth crown blades based on leaf / disk structure were analyzed.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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