共查询到19条相似文献,搜索用时 171 毫秒
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非线性弹性转子系统碰摩的动态特性 总被引:4,自引:0,他引:4
在同时考虑轴承油膜力、转轴非线性弹性力和碰摩发生时转静件问的相对速度对非线性摩擦力的影响基础上,构造了具有碰摩故障转子一轴承系统的动力学模型,对系统在运行过程中的非线性行为进行了数值仿真分析,发现在亚临界转速区,系统响应主要以周期运动为主,在半倍临界转速附近有短暂的混沌运动。在临界转速区,系统响应为周期运动,振幅相应增大。在超临界转速区,系统响应以混沌、周期分频和拟周期为主要运动形式。不同的速度影响因数对系统的响应也具有一定的影响。该结果为转子-轴承系统的故障诊断提供了一定的参考。 相似文献
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转子-定子系统松动-碰摩耦合故障的动态响应分析 总被引:2,自引:0,他引:2
建立了考虑定子与基础之间的连接刚度和阻尼(包括定子本身运动)的转子-定子系统发生松动-碰摩时的动力学模型和微分方程,对系统在运行过程中的非线性行为进行了数值仿真分析,发现随着转速的变化过程,此类系统响应主要以拟周期或阵发性分岔进入混沌,而由拟周期或倍周期倒分岔离开混沌。在超临界转速区,系统的响应以混沌和周期k的分频运动为主要运动形式。该结果为转子-定子系统的故障诊断提供了依据和参考。 相似文献
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建立了短轴承模型的非线性转子系统发生碰摩时的数学模型,结合数值仿真计算对碰摩转子所表现出的动力学特性进行研究,分析表明系统除具有各种形式的周期和拟周期振动以外,还具有丰富的混沌运动和分岔现象.用数值方法得到系统在某些参数域中的分岔图、轴心轨迹、庞加莱映射图、响应曲线和频谱图,直观显示了系统在某些参数域中的运行状态;同时研究了不平衡量对转子系统响应的影响,数值分析结果为该类转子系统的理论分析与故障诊断提供了参考. 相似文献
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《动力工程学报》2016,(10):788-794
在考虑裂纹轴时变刚度、碰摩力和非线性油膜力的基础上,建立了裂纹-碰摩双故障转子-轴承系统的非线性动力学模型,采用数值积分方法对其进行求解,结合分岔图、poincaré截面图、轴心轨迹图和最大Lyapunov指数(LLE)曲线图,从定性和定量的角度分析了无量纲裂纹深度和转速对系统响应、稳定性及碰摩力的影响.结果表明:该类转子-轴承系统出现了p-2、p-4、p-8、拟周期和混沌等丰富的非线性运动;随着无量纲裂纹深度的增加,系统首次分岔点转速提高,进入拟周期和混沌等运动的临界转速提前;在高速区间,随着无量纲裂纹深度的增加,系统响应由拟周期运动演变为混沌和多周期运动交替出现;在不同转速阶段,裂纹的加深对碰摩力的影响不同,在高速区间的影响更为明显. 相似文献
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利用满足工程精度的平均本征值法得到有限宽轴承的油膜力。以轴承一裂纹转子系统为研究对象,用数值积分法研究了系统的非线性动力学行为。借助Poincare映射、谱分析和Lyapunov指数分析了系统的运动形态。结果发现,随着系统参数的变化,在特定的参数组合下出现了由倍周期分岔导致的混沌现象。平均本征值法在此文中应用的成功为该方法进一步应用到工程实际提供了依据。图7参9 相似文献
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汽轮机转子与静子间的碰磨严重影响着机组的安全运行。为了解决汽轮机转子发生在早期和中期的碰磨故障难以通过基于振动信号检测诊断方法进行有效识别的问题,本文提出一种基于EEMD-LSTM的汽轮机转子碰磨故障诊断方法。首先,该方法通过声发射技术监测汽轮机转子的碰磨故障信号;然后,利用EEMD信号分解方法处理获取的声发射信号,并提取能量特征参数和相关的时域特征参数,从而获得碰磨故障特征数据集;最后,利用划分的数据集对LSTM神经网络进行训练与测试,从而获得碰磨故障诊断模型。工程应用结果表明,本文提出的方法能够有效识别机组在不同转速时期的早期碰磨故障,且故障诊断的准确率较高。 相似文献
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《International Journal of Hydrogen Energy》2023,48(30):11352-11369
Isoreticular metal organic framework (IRMOF) material is a type of ideal hydrogen storage material for its porosity and large surface area. Lithium doping and fullerene impregnation can enhance the hydrogen storage capacity of IRMOF efficiently. In this paper, the nonlinear dynamic characteristics of Li-doped fullerene-IRMOF composite material are qualitatively discussed in theory, which determine its thermal stability. A type of Li-doped fullerene-IRMOF composite material is proposed for hydrogen storage, and a new constitutive model is proposed to describe the hysteretic property of IRMOF. The system's nonlinear dynamic model is developed, and the fast-slow dynamic analysis method is introduced to interpret not only the system's jumping phenomena between the multi-pulse homoclinic and heteroclinic orbits but also its chaotic dynamics. The nonlinear dynamic responses of the system under deterministic and stochastic excitation are obtained respectively, and symmetrical and asymmetric orbital fusion phenomena have been discovered. The results of theoretical analysis and numerical simulation both show that the system has novel nonlinear dynamic characteristics such as double periodic motion, multi-pulse jumping orbits, and chaos; multi-pulse jumping phenomena are caused by the stiffness difference between fullerene and IRMOF, which form a fast-slow system; symmetrical fusion and asymmetrical fusion of system's orbits occur under different parameters. Safe, efficient and rapid hydrogen storage and release can be achieved through controlling the system's parameters to adjust the dynamic behavior of the system, which will be a development direction in the application of hydrogen energy. 相似文献
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In this paper, a possible reason for oscillation phenomena in a diesel-generator set is investigated through digital and analog network simulations. The nonlinear simulations of a swing equation show sudden deviations in the amplitude of rotor angle oscillations, provided that there exist periodic fluctuations of mechanical inputs to the generator unit. This kind of oscillation, different from the one that is identified in linear resonance, is thought to be caused by system nonlinearities and ill-combination of system parameters. The results of the analog simulations show the occurrence of bifurcation phenomenon in a electrical power mode. An approximate nonlinear model of the swing equation is found to hold the form of Duffing's equation. From the viewpoint of Duffing's equation, an instability assessment method is proposed using a catastrophe theory analogy 相似文献