查询词典 vibration number

The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

Based on the Betti-Rayleigh dynamic reciprocal theorem, the reciprocal property of the Green function is demonstrated; and the analytical solution of soil vibration subjected to moving loads is deduced. By means of double Fourier integral transform, the problem is firstly transformed into wave number-frequency domain, which makes it very convenient to derive the solution and furthermore to analyze the frequency characteristics of soil vibration.

基于Betti-Rayleigh动力互易定理，论证了地基土Green函数的互易性，推导了移动荷载引起的地基土振动解析解，进而推证出移动常力荷载和移动简谐荷载作用下地基于表面振动在波数－频率域内和空间－时间域内的解析表达式，并采用Matlab对其进行数值计算。

But the space is the matter, the matter is the string vibration, only has from this the time which vibrates f=1/T to draw out only then has the physics significance, therefore T is in the true significance time, from this deduction: What imaginary number Ict expresses is void, may write *ct,=I pure imaginary number, also is it with Number space Sigma (x1i*x2j)(i, j is subscript, i=j=1,2,3) differs 90 in the space, the shape for example: Psi ==a+Ib, constitutes a duplicate space by psi i* psi j,(definition mark * for ordinary multiplication) may use Four single numbers

而空间就是物质，物质就是弦的振动，只有从这个振动f=1/T引出的时间才有物理意义，所以T才是真正意义上的时间，由此推论：虚数Ict所表达的是一个虚空间，可以写成*ct，=I纯虚数，也即它与实空间Σ(x1i*x2j)(i，j为下标，i=j=1，2，3)在空间上相差90度，形如：ψ==a+Ib，由ψi*ψj构成一个复空间，可用四元数

By using the transfer matrix method of multibody system, the hard problem of computation of the vibration characteristics of LRMLRS coupled with rigid bodies and elastic bodies is solved which is very difficult to the ordinary dynamic methods, and the vibration characteristics of LRMLRS which is varied when the number of rockets in the launch device is varied, is obtained conveniently. By developing augmented eigenvectors of the LRMLRS and its orthogonality conditions, the nonorthogonality problem of the multibody system including rigid bodies and elastic bodies is solved and the exact analysis of the dynamics response of the LRMLRS including rigid bodies and elastic bodies is realized. By using the random integer programming method, the hard optimization problem which contains continuous variables, discrete variables and random variables at the same time is solved. This method provides a technology for optimum design with random variables and discrete variables. The dynamic optimum design is realized to decrease the number of rockets consumption in the LRMLRS test. The simulation system of dispersion of fire is established by using the maximum entropy method to estimate dispersion of fire.

通过应用多体系统传递矩阵法，解决了刚弹耦合远程多管火箭多体系统振动特性这一通常力学方法不便于解决的计算难题，方便地获得了远程多管火箭振动特性及其随发射架上火箭弹个数变化而变化的情况；通过构造增广特征矢量及其正交性条件，解决了刚弹耦合多体系统特征矢量不具有通常意义下的正交性的难题，实现了对刚弹耦合远程多管火箭动力响应的精确分析；应用随机整数规划法，解决了同时考虑连续、离散和随机变量等多种设计变量的优化设计难题，为含随机和离散变量的优化设计提供了手段，实现了减少远程多管火箭试验用弹量的动态优化设计；建立了应用最大熵法估计的密集度仿真系统，优化射序和射击间隔，实现了提高远程多管火箭射击密集度的动态优化。

Finally, analyse the calculated results of this ship with another catamarans. From this result obtained unsymmetrical catamaran hull of this particular special vibration mode and analyse the vibration mode in order. The calculation is fairly reasonable, for the future of the asymmetric catamarans to calculate the vibration analysis of a number of reference.

最后将本船计算结果与另一艘双体船计算结果进行了比较分析，得到不对称双体船这种特殊船型的特殊振动模态，并就其振动模态出现次序进行了比较分析，说明本次计算是比较合理的，为今后不对称双体船的振动特性分析计算提供了一些的参考。

A number of electromagnetic vibration exciters of a large size have been produced for vibration testing in the aircraft and missile industries.

为了进行航空及导弹工业的振动试验，已经建造了若干大型电磁式激振器。

Based on this, cacelled the vibration noise with appropriate weight number and step size.From the research work in this paper,it is shown that the vibration noise can be cancelled effectively and cetain cancellation can be obtained in

同时，研究结果还表明：采用归一化LMS自适应滤波器进行舷侧阵振动噪声抵消的效果优于传统的LMS算法自适应滤波器，更有利于满足实时处理的要求。

The fatigue vibration test of corrugated fiberboard was conducted. The influence of the number of vibration and vibration acceleration on the load capacity and cushion coefficient of corrugated fiberboard were determined and compared with non-vibrated corrugated fiberboard.

对瓦楞纸板进行疲劳振动试验，测定分析振动次数、加速度对瓦楞纸板承载能力、缓冲性能的影响，并与未经振动材料进行比较。

Against the background of wind-induced vibration of the H-shaped hangers of steel truss arch bridges,this paper analyzes the degree of influences of the Reynolds number Re,vibration factor ξ,stress magnitude,stress state,boundary conditions and sectional shapes of hangers on the vibration of the hangers of the steel truss arch bridges.

以钢桁拱桥的H型吊杆的风致振动为工程背景，分析了吊杆的雷诺数Re、振动因子ξ、应力大小及应力状态、边界条件、断面形状对钢桁拱桥吊杆振动的影响程度。

Against the background of wind-induced vibration of the H-shaped hanger s of steel truss arch bridges,this paper analyzes the degree of influences of the Reynolds number Re,vibration factor ξ,stress magnitude,stress state,boundary conditions and sectional shapes of hanger s on the vibration of the hanger s of the steel truss arch bridges.

以钢桁拱桥的H型吊杆的风致振动为工程背景，分析了吊杆的雷诺数Re、振动因子ξ、应力大小及应力状态、边界条件、断面形状对钢桁拱桥吊杆振动的影响程度。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。