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Nonlinear Dynamics Behaviors of a Rotor Roller Bearing System with Radial Clearances and Waviness Considered 被引量:15
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作者 王黎钦 崔立 +1 位作者 郑德志 古乐 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第1期86-96,共11页
A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces ... A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces of a roller bearing under four-dimensional loads and establishes 4-DOF dynamics equations of a rotor roller bearing system. The methods of Newmark-β and of Newton-Laphson are used to solve the nonlinear equations. The dynamics behaviors of a rigid rotor system are studied through the bifurcation, the Poincar è maps, the spectrum diagrams and the axis orbit of responses of the system. The results show that the system is liable to undergo instability caused by the quasi-periodic bifurcation, the periodic-doubling bifurcation and chaos routes as the rotational speed increases. Clearances, outer race waviness, inner race waviness, roller waviness, damping, radial forces and unbalanced forces-all these bring a significant influence to bear on the system stability. As the clearance increases, the dynamics behaviors become complicated with the number and the scale of instable regions becoming larger. The vibration frequencies induced by the roller bearing waviness and the orders of the waviness might cause severe vibrations. The system is able to eliminate non-periodic vibration by reasonable choice and optimization of the parameters. 展开更多
关键词 roller bearing rotor system nonlinear bearing force dynamics behaviors BIFURCATION CHAOS
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Effectof Film Force Nonlinearity on Unbalance Responseof a Jeffcot RotorJournal Bearing System 被引量:1
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作者 ZHANG Zhi ming ZHU Li jin YU Jun (School of Mechanical and Electronic Engineering, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第3期227-233,共7页
The effect of oil film force nonlinearity on unbalance response of Jeffcot rotor elliptical bearing system is studied. Linear analysis is done by linearizing the bearing oil film dynamic forces and expressing them wi... The effect of oil film force nonlinearity on unbalance response of Jeffcot rotor elliptical bearing system is studied. Linear analysis is done by linearizing the bearing oil film dynamic forces and expressing them with stiffness and damping constants. Nonlinear dynamic simulation is done by taking the nonlinearity of bearing oil film dynamic force into full consideration, with the latter being expressed by a special database which is generated beforehand, and based on non stationary Reynolds equation and Reynolds boundary condition of film rupture. The linear and nonlinear unbalance responses of a Jeffcot rotor supported on a pair of elliptical bearings is studied. The resulting dynamic characteristics and rotor and journal whirling orbits are compared. While good consistancy between nonlinear and linear predictions is found under very small unbalance, significant or even drastic differences are found whenever the unbalance is not small, indicating the necessity of including the nonlinearity of oil film dynamic forces, especially when response to large unbalance is to be predicted. 展开更多
关键词 rotor dynamics dynamic simulation unbalance response nonlinear bearing force
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Nonlinear Vibration Induced by the Water-film Whirl and Whip in a Sliding Bearing Rotor System 被引量:3
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作者 ZHAI Liming LUO Yongyao +2 位作者 WANG Zhengwei KITAUCHI Seishiro MIYAGAWA Kazuyoshi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期260-270,共11页
Many industrial applications and experiments have shown that sliding bearings often experience fluid film whip due to nonlinear fluid film forces which can cause rotor-stator rub-impact failures. The oil-film whips ha... Many industrial applications and experiments have shown that sliding bearings often experience fluid film whip due to nonlinear fluid film forces which can cause rotor-stator rub-impact failures. The oil-film whips have attracted many studies while the water-film whips in the water lubricated sliding bearing have been little researched with the mechanism still an open problem. The dynamic fluid film forces in a water sliding bearing are investigated numerically with rotational, whirling and squeezing motions of the journal using a nonlinear model to identify the relationships between the three motions. Rotor speed-up and slow-down experiments are then conducted with the rotor system supported by a water lubricated sliding bearing to induce the water-film whirl/whip and verify the relationship. The experimental results show that the vibrations of the journal alternated between increasing and decreasing rather than continuously increasing as the rotational speed increased to twice the first critical speed, which can be explained well by the nonlinear model. The radial growth rate of the whirl motion greatly affects the whirl frequency of the journal and is responsible for the frequency lock in the water-film whip. Further analysis shows that increasing the lubricating water flow rate changes the water-film whirl/whip characteristics, reduces the first critical speed, advances the time when significant water-film whirling motion occurs, and also increases the vibration amplitude at the bearing center which may lead to the rotor-stator rub-impact. The study gives the insight into the water-film whirl and whip in the water lubricated sliding bearing. 展开更多
关键词 rotor system sliding bearing vibration water-film whip nonlinear
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Optimizing control of a two-span rotor system with magnetorheological fluid dampers 被引量:1
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作者 邢健 何立东 +1 位作者 王锎 黄秀金 《Journal of Beijing Institute of Technology》 EI CAS 2015年第4期558-565,共8页
A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological (MRF) dampers is designed. A finite element model of the MRF damper- rotor system is built and used to a... A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological (MRF) dampers is designed. A finite element model of the MRF damper- rotor system is built and used to analyze the rotor vibration characteristics. Based on Hooke and Jeeves algorithm and the numerical simulation analysis, an optimal appropriate controller is proposed and designed. Experimental results show that rotor vibration caused by unbalance is well controlled ( first critical speed region 37% , second critical speed region 42% ). To reflect advantages of optimi- zing strategy presented and validate the intelligent optimization control technology, detailed experi- ments were developed on a two-span rotor-vibration-control platform. The influence on accuracy, rapidity and stability of optimizing control for rotor vibration are analyzed. It provides a powerful technical support for the extension and application in target and control for shafting vibration. 展开更多
关键词 magnetorheological fluid damper two-span rotor Hooke and Jeeves optimizing con-trol vibration reduction
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NONLINEAR DYNAMIC CHARACTERISTICS OF HYDRODYNAMIC JOURNAL BEARING-FLEXIBLE ROTOR SYSTEM 被引量:7
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作者 LuYanjun YuLie LiuHeng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第1期58-63,共6页
The nonlinear dynamic behaviors of flexible rotor system with hydrodynamicbearing supports are analyzed. The shaft is modeled by using the finite element method that takesthe effect of inertia and shear into considera... The nonlinear dynamic behaviors of flexible rotor system with hydrodynamicbearing supports are analyzed. The shaft is modeled by using the finite element method that takesthe effect of inertia and shear into consideration. According to the nonlinearity of thehydrodynamic journal bearing-flexible rotor system, a modified modal synthesis technique withfree-interface is represented to reduce degrees-of-freedom of model of the flexible rotor system.According to physical character of oil film, variational constrain approach is introduced tocontinuously revise the variational form of Reynolds equation at every step of dynamic integrationand iteration. Fluid lubrication problem with Reynolds boundary is solved by the isoparametricfinite element method without the increasing of computing efforts. Nonlinear oil film forces andtheir Jacobians are simultaneously calculated and their compatible accuracy is obtained. Theperiodic motions are obtained by using the Poincare -Newton-Floquet (PNF) method. A method,combining the predictor-corrector mechanism to the PNF method, is presented to calculate thebifurcation point of periodic motions to be subject to change of system parameters. The localstability and bifurcation behaviors of periodic motions are obtained by Floquet theory. The chaoticmotions of the bearing-rotor system are investigated by power spectrum. The numerical examples showthat the scheme of this study saves computing efforts but also is of good precision. 展开更多
关键词 nonlinear dynamics Bearing-rotor system STABILITY BIFURCATION ChaosFinite element method
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Nonlinear dynamic behaviors of ball bearing rotor system 被引量:1
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作者 王黎钦 崔立 +1 位作者 郑德志 古乐 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期284-288,共5页
Nonlinear forces and moments caused by ball bearing were calculated based on relationship of displacement and deflection and quasi-dynamic model of bearing.Five-DOF dynamic equations of rotor supported by ball bearing... Nonlinear forces and moments caused by ball bearing were calculated based on relationship of displacement and deflection and quasi-dynamic model of bearing.Five-DOF dynamic equations of rotor supported by ball bearings were estimated.The Newmark-β method and Newton-Laphson method were used to solve the equations.The dynamic characteristics of rotor system were studied through the time response,the phase portrait,the Poincar?maps and the bifurcation diagrams.The results show that the system goes through the quasi-periodic bifurcation route to chaos as rotate speed increases and there are several quasi-periodic regions and chaos regions.The amplitude decreases and the dynamic behaviors change as the axial load of ball bearing increases;the initial contact angle of ball bearing affects dynamic behaviors of the system obviously.The system can avoid non-periodic vibration by choosing structural parameters and operating parameters reasonably. 展开更多
关键词 ball bearing rotor system nonlinear bearing force dynamic behaviors
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Complex nonlinear behaviors of a rotor dynamical system with non-analytical journal bearing supports 被引量:1
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作者 吕延军 虞烈 +1 位作者 刘恒 张永芳 《Journal of Shanghai University(English Edition)》 CAS 2006年第3期247-255,共9页
Nonlinear dynamic behaviors of a rotor dynamical system with finite hydrodynamic bearing supports were investigated. In order to increase the numerical accuracy and decrease computing costs, the isoparametric finite e... Nonlinear dynamic behaviors of a rotor dynamical system with finite hydrodynamic bearing supports were investigated. In order to increase the numerical accuracy and decrease computing costs, the isoparametric finite element method based on variational constraint approach is introduced because analytical bearing forces are not available. This method calculates the oil film forces and their Jacobians simultaneously while it can ensure that they have compatible accuracy. Nonlinear motion of the bearing-rotor system is caused by strong nonlinearity of oil film forces with respect to the displacements and velocities of the center of the rotor. A method consisting of a predictor-corrector mechanism and Newton-Raphson method is presented to calculate equilibrium position and critical speed corresponding to Hopf bifurcation point of the bearing-rotor system. Meanwhile the dynamic coefficients of bearing are obtained. The nonlinear unbalance periodic responses of the system are obtained by using Poincaré-Newton-Floquet method and a combination of predic- tor-corrector mechanism and Poincaré-Newton-Floquet method. The local stability and bifuration behaviors of periodic motions are analyzed by the Floquet theory. Chaotic motion of long term dynamic behaviors of the system is analyzed with power spectrum. The numerical results reveal such complex nonlinear behaviors as periodic, quasi-periodic, chaotic, jumped and coexistent solutions. 展开更多
关键词 nonlinear dynamics journal bearing-rotor system BIFURCATION CHAOS stability finite element method.
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NONLINEAR DYNAMICS OF A CRACKED ROTOR IN A MANEUVERING AIRCRAFT
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作者 林富生 孟光 Eric Hahn 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第10期1139-1150,共12页
The nonlinear dynamics of a cracked rotor system in an aircraft maneuvering with constant velocity or acceleration was investigated. The influence of the aircraft climbing angle on the cracked rotor system response is... The nonlinear dynamics of a cracked rotor system in an aircraft maneuvering with constant velocity or acceleration was investigated. The influence of the aircraft climbing angle on the cracked rotor system response is of particular interest and the results show that the climbing angle can markedly affect the parameter range for bifurcation, for quasi-periodic response and for chaotic response as well as for system stability. Aircraft acceleration is also shown to significantly affect the nonlinear behavior of the cracked rotor system, illustrating the possibility for on-line rotor crack fault diagnosis. 展开更多
关键词 cracked rotor maneuvering aircraft nonlinear response fault diagnosis
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Nonlinear aeroelastic coupled trim and stability analysis of rotor-fuselage
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作者 胡新宇 韩景龙 喻梅 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第2期237-246,共10页
Based on the Hamilton principle and the moderate deflection beam theory, discretizing the helicopter blade into a number of beam elements with 15 degrees of freedora, and using a quasi-steady aero-model, a nonlinear c... Based on the Hamilton principle and the moderate deflection beam theory, discretizing the helicopter blade into a number of beam elements with 15 degrees of freedora, and using a quasi-steady aero-model, a nonlinear coupled rotor/fuselage equation is established. A periodic solution of blades and fuselage is obtained through aeroelastic coupled trim using the temporal finite element method (TEM). The Peters dynamic inflow model is used for vehicle stability. A program for computation is developed, which produces the blade responses, hub loads, and rotor pitch controls. The correlation between the analytical results and related literature is good. The converged solution simultaneously satisfies the blade and the vehicle equilibrium equations. 展开更多
关键词 nonlinear aeroelasticity rotor/fuselage coupling temporal finite elementmethod (TEM) stability
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QUANTITATIVE METHODOLOGY FOR STABILITY ANALYSIS OF NONLINEAR ROTOR SYSTEMS
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作者 郑惠萍 薛禹胜 陈予恕 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第9期1138-1145,共8页
Rotor-bearings systems applied widely in industry are nonlinear dynamic systems of multi-degree-of-freedom. Modem concepts on design and maintenance call for quantitative stability analysis. Using trajectory based sta... Rotor-bearings systems applied widely in industry are nonlinear dynamic systems of multi-degree-of-freedom. Modem concepts on design and maintenance call for quantitative stability analysis. Using trajectory based stability-preserving and dimensional-reduction, a quantitative stability analysis method for rotor systems is presented. At first, an n-dimensional nonlinear non-autonomous rotor system is decoupled into n subsystems after numerical integration. Each of them has only onedegree-of-freedom and contains time-varying parameters to represent all other state variables. In this way, n-dimensional trajectory is mapped into a set of one-dimensional trajectories. Dynamic central point (DCP) of a subsystem is then defined on the extended phase plane, namely, force-position plane. Characteristics of curves on the extended phase plane and the DCP's kinetic energy difference sequence for general motion in rotor systems are studied. The corresponding stability margins of trajectory are evaluated quantitatively. By means of the margin and its sensitivity analysis, the critical parameters of the period doubling bifurcation and the Hopf bifurcation in a flexible rotor supported by two short journal bearings with nonlinear suspensionare are determined. 展开更多
关键词 nonlinear rotor system BIFURCATION stability margin extended phase plane dynamic central point kinetic energy difference sequence
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Magnetic field effects on the nonlinear vibration of a rotor
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作者 M.EFTEKHARI A.DASHTI-RAHMATABADI A.MAZIDI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2020年第2期289-312,共24页
The nonlinear vibration of a rotor operated in a magnetic field with geometric and inertia nonlinearity is investigated. An asymmetric magnetic flux density is generated,resulting in the production of a load on the ro... The nonlinear vibration of a rotor operated in a magnetic field with geometric and inertia nonlinearity is investigated. An asymmetric magnetic flux density is generated,resulting in the production of a load on the rotor since the air-gap distribution between the rotor and the stator is not uniform. This electromagnetic load is a nonlinear function of the distance between the geometric centers of the rotor and the stator. The nonlinear equation of motion is obtained by the inclusion of the nonlinearity in the inertia, the curvature, and the electromagnetic load. After discretization of the governing partial differential equations by the Galerkin method, the multiple-scale perturbation method is used to derive the approximate solutions to the equations. In the numerical results, the effects of the electromagnetic parameter load, the damping coefficient, the amplitude of the initial displacement, the mass moment of inertia, and the rotation speed on the linear and nonlinear backward and forward frequencies are investigated. The results show that the magnetic field has significant effects on the nonlinear frequency of oscillation. 展开更多
关键词 nonlinear VIBRATION in-extensional rotor nonlinear CURVATURE gyroscopic effect MAGNETIC field
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Nonlinear Analysis of Shape Memory Alloy Component in Rotor System
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作者 王洪礼 赵涛 竺致文 《Transactions of Tianjin University》 EI CAS 2004年第4期252-254,共3页
The active control of rotor vibration was studied while shape memory alloy (SMA) spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SM... The active control of rotor vibration was studied while shape memory alloy (SMA) spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SMA with electric heating method. The SMA spring component has nonlinear coupling problem of thermal stress and thermal elasticity,because thermal constants α,β and elasticity constants λ,G vary with temperature when temperature changes sharply. Because δ,ε were both small parameters, their square items could be ignored and approximate results were obtained by perturbation. The characters of α,β,λ,G changing with temperature were analyzed. Results show that the character of thermal diffusivity α changes with temperature, which cannot influence U,Ψ,So the nonlinearity of α can be ignored; the character of β changes with temperature, which cannot influence U, but influences Ψ at high temperature; the character of λ,G change with temperature, which cannot influence Ψ, but influences U with U(01) ε. The more λ,G, the more their influence on U; the nonlinearity of βTρcvεkk influences U and Ψ, which must be calculated. 展开更多
关键词 shape memory alloy(SMA) rotor COUPLING nonlinear
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Analysis on Nonlinear Dynamic Properties of Dual-Rotor System
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作者 Hongliang Li Yushu Chen 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第5期46-54,共9页
In order to clarify the effects of support structure on a dual-rotor machine,a dynamic model is established which takes into consideration the contact force of ball bearing and the cubic stiffness of elastic support. ... In order to clarify the effects of support structure on a dual-rotor machine,a dynamic model is established which takes into consideration the contact force of ball bearing and the cubic stiffness of elastic support. Bearing clearance,Hertz contact between the ball and race and the varying compliance effect are included in the model of ball bearing. The system response is obtained through numerical integration method,and the vibration due to the periodic change of bearing stiffness is investigated. The motions of periodic,quasiperiodic and even chaotic are found when bearing clearance is used as control parameter to simulate the response of rotor system. The results reveal two typical routes to chaos: quasi-periodic bifurcation and intermittent bifurcation. Large cubic stiffness of elastic support may cause jump and hysteresis phenomena in resonance curve when rotors run at the critical-speed region. The modeling results acquired by numerical simulation will contribute to understanding and controlling of the nonlinear behaviors of the dual-rotor system. 展开更多
关键词 dual-rotor system ball bearing elastic support nonlinear dynamics BIFURCATION CHAOS
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双转子-中介轴承系统动力学仿真与实验研究
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作者 向玲 陈凯乐 +2 位作者 李林春 邴汉昆 胡爱军 《动力工程学报》 CAS CSCD 北大核心 2024年第7期1033-1041,1050,共10页
针对双转子系统复杂的动力学特性以及总是存在的质量不平衡现象,建立内外双转子系统动力学模型,通过轴心轨迹图、时域图、频谱图、庞加莱截面图和分岔图分析其振动特性,并通过双转子系统实验台升速和不平衡实验验证了理论和仿真结果。... 针对双转子系统复杂的动力学特性以及总是存在的质量不平衡现象,建立内外双转子系统动力学模型,通过轴心轨迹图、时域图、频谱图、庞加莱截面图和分岔图分析其振动特性,并通过双转子系统实验台升速和不平衡实验验证了理论和仿真结果。结果表明:双转子系统在升速过程中会发生2次振幅突然加剧的现象,2次主共振分别由内、外转子转速达到系统固有频率引起;双转子系统在不同的转速下会呈现出不同的振动特性;增大内转子的不平衡量,不仅会影响内转子系统振动响应,还会影响外转子系统振动响应,并且对前者的影响更显著。 展开更多
关键词 双转子系统 动力学 中介轴承 非线性响应 实验研究
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分数阶转子-轴承耦合系统非线性动力学分析
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作者 孙万泉 王报霞 《水力发电学报》 CSCD 北大核心 2024年第2期23-32,共10页
为深入挖掘水轮发电机组转子-轴承系统的非线性耦合振动特性,将该系统的阻尼力从传统的固定整数阶扩展到灵活多变的分数阶范围。建立了含分数阶阻尼的转子与含分数阶的轴承在耦合作用下的动力学模型,分析了不同分数阶阶次对系统的影响,... 为深入挖掘水轮发电机组转子-轴承系统的非线性耦合振动特性,将该系统的阻尼力从传统的固定整数阶扩展到灵活多变的分数阶范围。建立了含分数阶阻尼的转子与含分数阶的轴承在耦合作用下的动力学模型,分析了不同分数阶阶次对系统的影响,探讨了含分数阶阻尼转子与轴承的耦合模型在阶次对称系统和阶次非对称系统中的不同运动形态,给出了系统不同条件下的运动状态分布图,对比了碰摩故障在整数阶和分数阶条件下不同形态的动力特征,验证了所提出分数阶阻尼的优越性。结果表明,分数阶阻尼相比于整数阶阻尼具有非局部性、记忆性和适应非线性等新的动力学特征。 展开更多
关键词 水力机械 转子-轴承系统 分数阶阻尼 非线性动力学 故障特征
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不确定转子系统动力学降阶模型构建与模型散度参数辨识 被引量:1
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作者 张义彬 刘保国 +1 位作者 刘彦旭 励精为治 《机电工程》 CAS 北大核心 2024年第3期438-444,共7页
在航空、航天、船舶等领域的实际工程转子系统中,广泛存在高维复杂的非线性系统。在航空发动机转子系统、燃气轮机转子系统等重点研究领域,通常还难以对高维复杂非线性系统进行直接的数据处理和分析统计。针对不确定性转子系统的模型维... 在航空、航天、船舶等领域的实际工程转子系统中,广泛存在高维复杂的非线性系统。在航空发动机转子系统、燃气轮机转子系统等重点研究领域,通常还难以对高维复杂非线性系统进行直接的数据处理和分析统计。针对不确定性转子系统的模型维度较高等问题,提出了一种模型不确定性动力学降阶计算模型构建和模型散度参数辨识方法。首先,根据确定性动力学模型和静态矩阵降阶方法,完善了确定性动力学降阶模型;然后,基于随机矩阵理论和非参数动力学建模方法,提出了不确定性动力学降阶模型;最后,利用系统确定性模型的一阶临界转速、振型和实验数据,对不确定性动力学模型的散度参数进行了辨识;为了验证散度参数辨识方法的有效性,笔者又在转子实验平台上进行了实验验证。研究结果表明:实验结果与降阶之后振动响应均值的差异性较小,且与不确定性动力学模型相差不超过10%,表明所采用的理论模型在描述转子系统行为方面具备了较高的准确性和可靠性,该模型可以为深入研究模型不确定性转子系统提供参考。 展开更多
关键词 转子-支承系统 不确定转子系统 动力学降阶模型 非线性系统 散度参数辨识 非参数建模方法 矩阵降阶方法
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转子-机匣耦合系统碰摩非线性特征研究
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作者 赵先锋 杨洋 +1 位作者 曾劲 杨翊仁 《四川轻化工大学学报(自然科学版)》 CAS 2024年第2期16-22,共7页
转子-机匣碰摩问题是航空发动机中最常见故障之一。在临界转速附近,转子振动幅值会急剧增大,超过转子-机匣初始间隙就会引起碰摩。为了进一步探究碰摩机理,建立了考虑阻尼的非线性碰摩力模型并将其耦合在转子-机匣系统模型中,采用四阶Ru... 转子-机匣碰摩问题是航空发动机中最常见故障之一。在临界转速附近,转子振动幅值会急剧增大,超过转子-机匣初始间隙就会引起碰摩。为了进一步探究碰摩机理,建立了考虑阻尼的非线性碰摩力模型并将其耦合在转子-机匣系统模型中,采用四阶Runge-Kutta法求解,给出了不同转速下转子-机匣系统的响应分岔图,研究了转子-机匣系统的振动响应。同时,分别讨论了碰撞恢复系数、碰摩间隙对转子运动和碰摩力的影响。结果表明:碰撞恢复系数减小会导致转子-机匣嵌入深度增大,从而导致碰摩力增大。碰摩间隙会改变碰摩的频率,且随着间隙的减小,碰摩的频率增大。 展开更多
关键词 转子 碰摩 非线性 分岔 耦合系统
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能量轨道下带碰摩的双转子系统振动特性分析
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作者 刘军 王敬寒 +1 位作者 王肖锋 葛为民 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2024年第8期1564-1575,共12页
为提高航空发动机的推重比和燃油效率,调整转子与机壳间的间隙变小,易发生碰摩故障问题,本文针对带碰摩双转子系统的非线性振动特性开展了定性、定量分析。建立了具有非线性弹簧特性和带碰摩故障双转子系统的非线性数学模型,通过仿真与... 为提高航空发动机的推重比和燃油效率,调整转子与机壳间的间隙变小,易发生碰摩故障问题,本文针对带碰摩双转子系统的非线性振动特性开展了定性、定量分析。建立了具有非线性弹簧特性和带碰摩故障双转子系统的非线性数学模型,通过仿真与数值分析调查了该模型复杂的碰撞、振动特性。对碰摩故障发生后和即将脱离时该系统的能量交换进行了定量分析,基于振动能量轨道的迁移过程分析了非线性振动特征和诱发机理。使用转子实验验证了数值仿真、理论分析结果和振动能量轨道。本文揭示了带碰摩故障的非线性双转子系统运行时振动变化规律,更好地分析了双转子系统的振动特征。 展开更多
关键词 双转子系统 非线性恢复力 非线性振动 碰摩故障 能量空间分析 能量轨道 轨道迁移 实验
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电机驱动非理想振动系统的索末菲效应
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作者 丁川 甘子川 +1 位作者 王笑 宋汉文 《力学学报》 EI CAS CSCD 北大核心 2024年第9期2731-2740,共10页
真实转子系统的电机输出功率有限且无法提供理想恒定驱动,随着电机输入电压升高,在系统固有频率附近会出现长时间平均转速停滞和多稳态跳跃,称为“索末菲(Sommerfeld)效应”.这类非理想电机启动时会经过索末菲效应作用区,而长期陷于这... 真实转子系统的电机输出功率有限且无法提供理想恒定驱动,随着电机输入电压升高,在系统固有频率附近会出现长时间平均转速停滞和多稳态跳跃,称为“索末菲(Sommerfeld)效应”.这类非理想电机启动时会经过索末菲效应作用区,而长期陷于这一区域时电机转速剧烈波动,会严重影响电机寿命.简化忽略转速波动而注重稳态平均转速,无法观察系统内部受力变化,因此借助数值分析研究电机系统与振动系统作用过程.建立了非理想直流电机-质体-不平衡转子系统的机电耦合动力学模型,通过Matlab/Simulink建模,分析了振动系统各内力分量的变化规律,考察了索末菲效应产生、演变和消失过程.观察到非理想系统进入共振区后,恢复力、惯性力和阻尼力将突然产生偶数倍频成份,导致系统在平均转速与固有频率渐进一致的前提下,产生快转、停转乃至反转剧烈交替切换的现象,并在输入电压大于临界电压后结束跳跃.研究描述了在非理想驱动下系统展现的非线性行为,最后为振动系统动力设计提供指导并确保动力设备正常运行. 展开更多
关键词 索末菲效应 转子系统 振动系统 非线性动力学
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高速飞轮与电机耦合动力学模型研究
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作者 何海婷 张昊随 柳亦兵 《太阳能学报》 EI CAS CSCD 北大核心 2024年第8期27-33,共7页
基于替代映射方法分别建立主动磁轴承和永磁同步电机的非线性模型,并与飞轮转子动力学模块、PID控制器等组件结合,构造高速飞轮转子与电机耦合的非线性动力学系统模型。仿真结果表明,替代映射方法计算得到的永磁同步电机齿槽转矩数值与... 基于替代映射方法分别建立主动磁轴承和永磁同步电机的非线性模型,并与飞轮转子动力学模块、PID控制器等组件结合,构造高速飞轮转子与电机耦合的非线性动力学系统模型。仿真结果表明,替代映射方法计算得到的永磁同步电机齿槽转矩数值与有限元模型结果之间误差较小,具有良好的精度,可正确描述其基频到多次倍频的振动特性。永磁同步电机转子偏心作用力随着转子振幅的增大而增强,会显著削弱主动磁轴承对飞轮转子的控制能力。基于前人“双弹簧”模型,结合永磁同步电机替代映射模型,建立包含主动磁轴承和永磁同步电机的“三弹簧”模型。仿真计算结果表明,永磁同步电机转子偏心作用力改变了飞轮转子的第二临界转速的频率和振幅,作用力较大和位置偏置会造成第二临界转速附近的运动失稳。 展开更多
关键词 储能 飞轮转子 磁轴承 永磁同步电机 非线性动力学 替代映射
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