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在转子轴承系统振动信号处理中,针对平稳信号的传统傅里叶变换精度较低、快变启动过程的非平稳信号频谱分析方法较复杂的问题,本文仿真构造了两类响应信号。通过对比给定信号参数与信号识别参数的误差研究了几种谱分析方法或过程的简便性和准确性。对转子系统振动平稳信号离散频谱分析时存在的误差进行了定量分析,利用比例插值法对误差进行校正,开发了高精度谱分析测试软件;分析了转子轴承系统快变过程非平稳振动信号的特征,探索了一种将t时空域非平稳信号转变为tn时空间域平稳信号的办法或过程,然后结合比例插值校正法对其进行频谱分析,再返回到t时空域获得某时刻的谱特征参数;构造了转子系统振动仿真信号检验了上述过程的准确性。研究结果表明:比例插值法提取的谱特征数据近乎与仿真信号设定值相等;针对本文构造的快变过程非平稳仿真信号,利用本文给出的谱分析过程产生的频率误差最大值为0.47%,幅值误差最大值为0.2%。本文的仿真研究为提出和考证新的谱分析方法提供了手段。 相似文献
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一类刚性约束转子碰摩的非光滑分析 总被引:2,自引:0,他引:2
本文建立并研究了一类与定子几何不对中的转子刚性碰摩模型,通过建立碰摩映射,将对不连续流非光滑系统的研究转化为对映射的研究。文中从几何角度分析了转子碰摩的机理并用数值方法得取了该类子碰摩的分岔和混沌等非一性结果。 相似文献
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具有裂纹-碰摩耦合故障转子-轴承系统的动力学研究 总被引:9,自引:0,他引:9
以非线性动力学和转子动力学理论为基础,分析了带有碰摩和裂纹耦合故障的弹性转子系统的复杂运动,在考虑轴承油膜力的同时构造了含有裂纹和碰摩故障转子系统的动力学模型。针对短轴承油膜力和碰摩-裂纹转子系统的强非线性特点,采用Runge-Kutta法对该系统由碰摩和裂纹耦合故障导致的非线性动力学行为进行了数值仿真研究,发现该类碰摩转子系统在运行过程中存在周期运动、拟周期运动和混沌运动等丰富的非线性现象,该研究结果为转子-轴承系统故障诊断、动态设计和安全运行提供理论参考。 相似文献
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基于Priestley(1967)演变功率谱模型,并采用Lin和Yang(1983)的建议,建立了脉动风速的非平稳功率谱模型。依据此模型,采用三维有限元法,建立了大跨桥梁非平稳耦合抖振运动方程。然后,将虚拟激励法和精细时程积分法相结合,建立了求解桥梁三维非平稳耦合抖振运动方程的快速算法。以某大跨悬索桥为例,分析了该桥的非平稳耦合抖振响应,并与平稳耦合抖振响应进行了比较。计算结果表明:随着脉动风速平稳部分持时的增大,非平稳抖振分析结果逐渐收敛于平稳抖振分析结果;但若脉动风速的平稳部分持时较短,非平稳抖振分析结果将低于平稳抖振分析结果。 相似文献
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转子系统振动变参控制中的瞬态响应 总被引:2,自引:0,他引:2
本文以可变参数的挤压油膜阻尼器作为控制元件,研究了转子在稳态转速及加速运动过程中进行变参控制时的瞬态响应问题。结果说明了对转子系统的振动进行分段变参控制,无论是在稳态还是在加速运动过程中,一般都可以取得满意的控制效果,不仅可以减小转子系统的振动,而且还可以使转子系统平稳地通过具有较大振动的共振区,但变参位置不应在多值转速区内。 相似文献
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弹性支承滑动轴承—转子系统稳定性的研究 总被引:3,自引:2,他引:3
本文研究弹性支承滑动轴承-转子系统的动力稳定性问题,建立了弹性支承滑动轴承-Jeffcott转子系统的力学模型,采用牛顿延拓法从理论上对该转子轴承系统的动力稳定性进行了分析,讨论弹性支承的刚度对系统稳定的影响,从而提出提高系统稳定性的有关措施。最后,依据理论分析,利用Jeffcott转子实验台,作者设计和加工了一副弹性支承器,通过刚性支承和弹性支承两个对比实验,对理论分析的结果进行了验证。实验结果 相似文献
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This paper is about numerical simulations of dissipation processes in rotor shaft joints of rotor systems. Based on measurement results a nonlinear simulation model of a lab centrifuge is stated. The effects of internal damping in combination with nonlinear stiffness and friction in the rotor shaft joint of the lab centrifuge are worked out. It is shown that the nonlinearities cause the amplitudes to rest limited once increased amplitudes due to internal damping appear. One focus is the derivation of suitable force laws describing the mechanisms of the components within the connection. 相似文献
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在螺桨盘转子系统的颤振涡动研究中,系统的安装刚度对转子的颤振涡动失稳有着重要的作用.对于飞机发动机,实际安装情况十分复杂,发动机短舱.安装节、机翼等对螺桨盘转子的运动均有影响.所以,在颤振涡动研究中,必须考虑轴头的动刚度.轴头的动刚度是通过动柔度转换而来的,而在动柔度的实验测量中必须解决几个技术问题,首先是提高信噪比.其次是消除工艺夹具带来的附加质量和附加转动惯量的影响,从而提高动刚度系数的测量精度.本文通过对模型转子以及某实际桨轴发动机转子轴头动刚度系数的测量及处理,阐述轴头动刚度矩阵的测量方法,以及有关技术问题的处理过程. 相似文献
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提了了一种简单的无粘旋转流体准三维模型,并给出了旋转流体对转子作用力的详细表达式,然后用该模型分析了部分充液刚性悬臂转子系统的稳定性,并与实验结果进行了比较,两者在定性上符合较好,准三维无粘流体模型与其它的无粘膜型一样也仅能用来分析无外阻尼或外阻尼较小的部分充液转子系统的稳定性问题。 相似文献
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介绍螺桨转子系统颤振涡动的一种算法。本算法考察桨叶的振动变形,桨轴-支承系统的振动特性,以及螺转子的不平衡力。利用本算法对一模型螺桨转子和一实际螺桨转子进行了分析计算,对螺桨转子轴头动刚度、浆叶弹性变形、桨盘不平衡度等因素对螺桨转子系统颤振涡动的影响进行了分析,表明螺桨转子轴头动刚度下降时,螺浆发生颤振涡动的极限飞行速度下降。模型螺桨转子的计算结果与风洞试验结果相当吻合,证明本算法是正确的。 相似文献
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系统参数随机性是影响准确预测转子动力学行为的重要因素。为此,研究了具有初始轴弯曲的不平衡柔性转子在故障参数随机情况下的不确定性分析问题。首先,基于转子动力学梁元有限元理论,推导了不平衡和轴弯曲故障共同作用下的系统稳态动力学方程,并以轴心轨迹长半轴作为关键响应量建立了柔性转子共振稳态响应与输入参数间的模型函数;其次,联合广义多项式混沌展开、留一法交叉验证以及最小角回归技术实现了柔性转子共振稳态响应的非嵌入式自适应稀疏多项式混沌展开,并与基于普通最小二乘法的多项式混沌展开和基于Monte Carlo仿真的结果作了对比分析,验证了自适应稀疏展开方案的有效性、精度和效率;最后,以构建的自适应稀疏多项式混沌展开式作为近似模型,重点分析了转子圆盘处一阶共振稳态响应的随机特性,并基于Sobol指标获得了响应对各故障参数的全局灵敏度指标。 相似文献
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Turbocharger rotor dynamics with foundation excitation 总被引:1,自引:0,他引:1
Guangchi Ying Guang Meng Jianping Jing 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(4):287-299
To investigate the effect of foundation excitation on the dynamical behavior of a turbocharger, a dynamic model of a turbocharger
rotor-bearing system is established which includes the engine’s foundation excitation and nonlinear lubricant force. The rotor
vibration response of eccentricity is simulated by numerical calculation. The bifurcation and chaos behaviors of nonlinear
rotor dynamics with various rotational speeds are studied. The results obtained by numerical simulation show that the differences
of dynamic behavior between the turbocharger rotor systems with/without foundation excitation are obviously. With the foundation
excitation, the dynamic behavior of rotor becomes more complicated, and develops into chaos state at a very low rotational
speed. 相似文献
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A nonlinear mathematical model for orbital motion of the rotor under the influence of leakage flow through a labyrinth seal was established in the present study. An interlocking seal was chosen for study. The rotor–seal system was modeled as a Jeffcot rotor subject to aerodynamic forcing induced by the leakage flow. Particular attention was placed on the serpentine flow path by spatially separating the aerodynamic force on the rotor surface into two parts, e.g., the seal clearance and the cavity volume. Spatio-temporal variation of the aerodynamic force on the rotor surface in the coverage of the seal clearance and the cavity volume was delineated by using the Muzynska model and perturbation analysis, respectively. The governing equation of rotor dynamics, which was incorporated with the aerodynamic force integrated over all seal clearances and cavity volumes, was solved by using the fourth-order Runge–Kutta method to obtain the orbit of the whirling rotor. Stability of the rotating rotor was inspected using the Liapunov first method. The results convincingly demonstrate that the destabilization speed of the rotor was reduced due to the aerodynamic force induced by the leakage flow through the interlocking seal. The nonlinear analysis method proposed in the present study is readily applied to dynamics of various rotor–seal systems with labyrinth seals. 相似文献
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Kuan Lu 《Nonlinear dynamics》2018,93(4):2003-2018
The first two moments of the steady-state response of the spring and rotor models are determined by the polynomial dimensional decomposition (PDD) method and the Monte Carlo simulation (MCS) method in this paper. Both the analytical and numerical cases of the PDD method in the dynamical models are provided, and the response of the numerical case is calculated via the harmonic balance and PDD methods. The PDD can describe the amplitude–frequency characteristics of the dynamical models with random variables except the frequencies around the resonant frequencies. These results are shown as a three-DOF spring model with stiffness uncertainty, rotor models with four and nine random variables and nonlinear rotor model with thirteen random variables, respectively. The effects of larger uncertainties and polynomial order are also highlighted. The efficiency of the PDD method is verified via comparing with the MCS method. The applications of the PDD method to the rotor model can provide guidance to further study the rotor systems supported by bearings. 相似文献