航空发动机螺栓连接转子的振动特性研究

发布时间：2019-05-16 09:50

【摘要】：螺栓连接结构简单,可操作强,安装方便,连接刚性良好,因此广泛应用于航空发动机转子连接结构中。由于工作环境复杂,螺栓连接结构也常常产生如预紧力松弛、疲劳失效等故障,而螺栓连接本身的非线性特性也使得被连接转子的实际运动状态相对复杂。另外开展航空发动机转子整体的细致化、参数化建模工作也势在必行,螺栓连接结构作为重要结构,其参数化工作也亟待开展。本文在总结先前学者研究成果的基础上开展了关于含螺栓连接转子系统的振动特性研究,结合有限元仿真计算进行了结构动力学研究,尤其进行了细致的非线性稳态动力学响应研究,主要工作和成果如下:1.细致地研究了螺栓连接在各个受力方向上的变形力学特性,分别从轴向,径向,以及弯曲变形三个方面给出了螺栓连接转子的定性参数化模型。讨论了一个含螺栓连接的薄壳结构在轴向、横向和弯曲变形的力学特性规律。2.设计构造了一个含有螺栓法兰连接的薄壳转子模型,使其近似航空发动机转子结构。基于Workbench对该模型进行了转子动力学研究,对于得到的坎贝尔图和各阶位移云图进行分析,发现了螺栓连接对转子临界转速的一些影响。3.基于有限元计算的内容建立了简化转子系统模型,采用数值计算方法着重分析了含螺栓连接系统的非线性稳态动力学响应。发现了等效预紧力变化对转子系统运动状态的影响规律,揭示了转子弯曲程度在转子系统动力学行为中起到的重要影响。并且分析了系统能量的集中位置,解释了在二阶临界转速附近发生复杂运动的原因。4.基于遗传算法设计了识别含螺栓连接转子系统非线性弯曲变形刚度的方法,对于不同噪声程度下的识别结果进行了比对,发现该方法在不同噪声影响下鲁棒性良好。本文在含有螺栓连接的航空发动机转子系统其非线性动力学研究上获得了一些成果,对于研究连接结构对转子动力学的影响有一定指导意义。
[Abstract]:The bolt connection structure is simple, the operation is strong, the installation is convenient, the connection rigidity is good, and therefore, the bolt connection structure is widely applied to the air engine rotor connecting structure. Due to the complex working environment, the bolt connection structure often results in a failure such as a pre-tightening force relaxation, a fatigue failure, and the like, and the non-linear nature of the bolt connection itself also makes the actual motion state of the connected rotor relatively complex. In addition, it is necessary to design the whole rotor of the aero-engine, and the parameterized modeling work is imperative, and the parametric work of the bolt connecting structure is also urgent. In this paper, on the basis of summarizing the research results of the previous scholars, the research on the vibration characteristics of the bolt-connected rotor system is carried out, and the structural dynamics research is carried out in combination with the finite element simulation calculation. In particular, the detailed nonlinear steady-state dynamic response study is carried out, and the main work and results are as follows: 1. The deformation and mechanical properties of the bolt connection in the stress direction are studied in detail, and the qualitative and parametric model of the bolt connection rotor is given from the three aspects of axial, radial and bending deformation, respectively. The mechanical properties of a thin-shell structure with bolted connection in axial, transverse and flexural deformation are discussed. A thin-shell rotor model with bolted flange connections is designed to approximate the structure of the aero-engine rotor. The rotor dynamics study of the model is carried out on the basis of Workbench, and the influence of the bolt connection on the critical speed of the rotor is found. The simplified rotor system model is established based on the finite element calculation, and the nonlinear steady-state dynamic response of the bolt-bearing system is analyzed by means of the numerical calculation method. The influence of the change of the equivalent pre-tightening force on the motion state of the rotor system is found, and the important influence of the rotor bending degree in the dynamic behavior of the rotor system is revealed. The concentrated position of the system energy is analyzed, and the cause of complex motion in the vicinity of the second-order critical speed is explained. Based on the genetic algorithm, a method for identifying the non-linear bending deformation stiffness of a bolt-bearing rotor system is designed, and the comparison is made on the recognition result under different noise levels, and the method has the advantages of good robustness under different noise effects. In this paper, some results have been obtained in the study of the nonlinear dynamics of the rotor system of the aero-engine with bolt connection, which is of great significance to the study of the influence of the connecting structure on the rotor dynamics.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V231.9

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