转子—支承系统动力学相似模型设计与实验研究

发布时间：2018-03-26 02:34

本文选题：转子-支承系统　切入点：相似关系　出处：《东北大学》2014年硕士论文

【摘要】：转子-支承系统作为旋转机械的核心部件,其动力学特性决定着旋转机械的工作性能和可靠程度。在对转子-支承系统动力学特性的研究中,除了基于数学模型的解析计算与计算机仿真外,模型实验同样是必不可少的一部分。模型实验可以避免原型实验所带来的高成本、高难度等诸多不利因素,同时为了使模型能更好的复现原型的动力学特性,本文对转子-支承系统的动力学相似模型设计方法进行了研究。本文首先结合描述转轴和弹性支承运动状态的微分方程,运用积分模拟法推导出转子-支承系统动力学相似关系表达式,并利用有限元仿真验证了相似关系在固有频率、模态振型以及临界转速方面的准确性。针对转子-支承系统模型设计时,支承刚度可能会不完全相似的情况,提出了一种使模型固有频率相对误差在10%范围内的支承刚度许用区间设计方法,并验证了该方法的正确性。本文验证了转子-支承系统动力学相似关系在能量分布方面的适用性,并将支承刚度许用区间设计方法运用到能量分布的不完全相似模型设计中,并验证了其可行性。在分析过程中还发现,应变能分布和总能量分布相对于转轴能量分布对支承刚度的变化更为敏感。最后针对原型转子实验台,利用转子-支承系统动力学相似关系,结合支承刚度许用区间设计方法设计了模型转子实验台,分别对原型系统和模型系统的固有频率、模态振型以及临界转速进行实验测试,并对结果进行对比分析,实验结果既证明了转子-支承系统动力学相似关系的准确性,也证明了提出的支承刚度许用区间设计方法的可行性。
[Abstract]:As the core component of rotating machinery, the dynamic characteristics of rotor-bearing system determine the working performance and reliability of rotating machinery. In addition to analytical calculation based on mathematical model and computer simulation, model experiment is also an essential part. Model experiment can avoid many disadvantages such as high cost, high difficulty and so on brought by prototype experiment. At the same time, in order to make the model better to reproduce the dynamic characteristics of the prototype, the dynamic similarity model design method of rotor-bearing system is studied in this paper. In this paper, the dynamic similarity expression of rotor-bearing system is derived by using the integral simulation method combined with the differential equation describing the motion state of rotary shaft and elastic support, and the similarity relation in natural frequency is verified by finite element simulation. The accuracy of modal mode and critical speed. In the case of rotor-support system model design, the stiffness of the support may not be completely similar. A design method of allowable interval of support stiffness with relative error of natural frequency in the range of 10% is proposed. In this paper, the applicability of the dynamic similarity relation of rotor-bearing system in energy distribution is verified, and the allowable interval design method of support stiffness is applied to the design of incomplete similarity model of energy distribution. It is also found that the strain energy distribution and the total energy distribution are more sensitive to the change of the support stiffness than the rotational shaft energy distribution. Based on the dynamic similarity of rotor-bearing system and the allowable interval design method of supporting stiffness, the model rotor test bench is designed. The natural frequency, modal mode and critical speed of the prototype system and the model system are tested respectively. The experimental results not only prove the accuracy of the dynamic similarity relation of rotor-bearing system, but also prove the feasibility of the proposed design method of allowable interval of supporting stiffness.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH113

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