查询词典 pincushion distortion

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。

Undercarriage distortion, axle distortion, and U-shaped bolt etc will lead to deflexion of front and back steering axles.

转向轴偏斜和转向轮偏转都严重影响汽车的直线行使。

In the case of determinacy time-base distortion, Author analysis two time-base distortion estimate arithmetic in common use.

对于造成采样时基误差中的确定性时基偏差问题，从理论上分析了在工程应用中两种常用的时基偏差估计算法估计性能优缺点，并利用仿真实验进行验证。

With the engineering data , the strut frame made of composed soil nails is analyzed with the program ababqus , and the effects of the distortion characters , the property of the deposition of the ground , the mechanical property of the soil nails , the variation of the length and the separation of the soil nails , and the diametric of the mixing piles on the strut frame made of composed soil nails , and the distortion property of the strut frame made of composed soil nails under different ground conditions

在总结前人的研究成果下，针对复合土钉墙构造的特点，建立了模拟复合土钉墙受力变形的计算模型，并结合工程实测资料，运用大型通用有限元程序ababqus对复合土钉墙进行了有限元分析，详细讨论了复合土钉支护结构开挖过程中的变形特性、地面沉降性状、土钉受力性状；土钉长度变化、土钉间距变化、搅拌桩桩径变化对复合土钉支护结构的影响；复合土钉支护结构在不同地基条件下的变形特性。

Through moving azimuth and pitching angle a distortion net of whole image was built. Then distortion model was set up with different models.

对整个视场进行抽样采点，得到一个畸变的网格场，通过拟合得到畸变系数，可以进行高准确度畸变修正。

When you watch from the other point of view, the backlight can penetrate as a result of next pixels into the human eye, it can cause color distortion, LCD display is the visual angle of view means to receive the attention of the distortion value of the angle with the normal screen.

当你从其他角度观看时，由于背光可以穿透旁边的像素而进入人眼，所以会造成颜色的失真，LCD显示器的可视角度就是指能观看到可接收失真值的视线与屏幕法线的角度。

It has been obtained that the distortion characteristics of the gently-slant rock mainly include asymmetrical distortion and obtuse angle destruction.

尝试采用以板状单元模拟缓倾层状岩体，对徐州矿区旗山矿缓倾（8°）层状岩体的产状及结构性特征进行模拟，再现了巷道的破坏全过程。

Using the simple caculation,ANSYS analysis caculation and testing may obtain the quantity of angle distortion based on the analysis of producing the spring distortion when the compressor worked with received the load.

分析压力机在承受负载时机身产生弹性变形的基础上，分别利用简化计算，有限元分析计算和测试获得角变形量并进行对照比较，提出3种方法存在的差异。

This angle distortion results from the rhombohedral symmetry of LSMO, when it is matched onto a cubic substrate. As the distortion angle is partially recovered in coherently LSMO films, the transition temperature T_P of the films almost approaches to that value of the LSMO bulk.

因此，菱形的LSMO匹配生长在立方单晶衬底上，除了受晶格参数失配引起的应变外，还存在另一种应变来自于LSMO匹配生长在立方衬底上引起的。

The method involves an iterative procedure, which incrementally flattens a 3D triangular mesh by region growing and obtains a parameterization with free boundary. The result is then converted to a parameterization with regular boundary by conformal mapping. Our method accounts for both the angle and area distortion during parameterization, it yields a parameterization with less global distortion and no triangular flipping.

采用区域增长算法逐层展平空间三角网格，得到空间三角网格曲面的自由边界的参数化结果，并利用保形变换将自由边界的参数化结果变换为规则边界的参数化结果；同时兼顾了参数化的角度变形和面积变形，使得参数化结果具有整体变形较小的特点，并能够避免三角形折叠的现象。

Talks resumed today between the Broadway producers' league and the striking stagehands' union as they tried to reach an agreement that would end the walkout that has left most theaters dark for 16 days.

百老汇制片人同盟与罢工的舞台管理同盟今天重新开始谈判，他们试图达成一项协议以结束罢工，罢工已经使大部分剧院关闭了16天。

A distribution law of aerodynamic force and moment is further developed from the genera formulas cooperating with the Navier-Stokes equation.

利用 Navier-Stokes 方程求出动力学涡量的变化率，进一步把力和力矩表示成一些显式积分。