结构化设计

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。

Using the waste water of life,cobining the principle of evaporation decalescence,design new material which can reduce the warm.

利用公寓生活废水的清洁与再利用，结合毛细现象以及蒸发吸热原理，模拟设计能够使建筑材料结构适合蒸发水分而达到降温的"有机化"建筑材料。

This paper shows in detail the techno1ogical theory of heat－ecomposition and the comparison of equipment of production of which light magnesium carbonate can be produced by the way of dolomite caronation, the structure of continuous tubular heat decomposer ,technological design, production characteristic and the effect ofsaving energy.

介绍了白云岩碳化法制造轻质碳酸镁工业装置中的热解工艺原理、生产设备比较和连续管式热解器的结构、工艺设计、生产特点及节能效果。

For the specification of the dynamic architecture of the system, the sub-function is designed as an abstract function with dynamic characteristic, which has a life-cycle of four phases: instantiation, establishment, execution and disestablishment.

为描述系统的动态结构，本文将子功能设计成一个具有动态特性的抽象功能，它有实例化、初始建立、功能执行和功能结束这样一个生命周期。

Finally the attraction domain of a kind of variable structure guidance, which is designed by zeroing sight angle rate, is shown that the valid of the analysis method is verified.

最后，针对零化视线角速率而设计的变结构制导律，确定了它的滑动模态吸引区，验证了理论分析方法的有效性。

In order to ensure system stability and reliability, use of pure software dual module hot spare mechanisms to achieve system reliability and stability, by dual module hot spare system architecture design, to implement the dual module hot spare system from the system start,"heartbeat" signal transduction, fault detection system and the main switching equipment for several major aspects.

为了保证系统的稳定性与可靠性，采用纯软件化的双机热备机制来实现系统的可靠性与稳定性，通过对双机热备系统进行总体结构设计，从系统启动，"心跳"信号传递，故障检测以及系统主备机切换等几个主要方面对双机热备系统予以实现。

It's found that the vibration characteristics can be controlled effectively by means of regulating the electric field intensity applied on actuators.

结果表明，材料梯度化可影响梁的固有频率，在结构设计中应予以考虑。

Based on analysis of the grinding shortcomings associated with brown emery wheel of the roller s skew tooth top-surface,a method was proposed,which used CBN grinding wheel in substitution for traditional brown emery wheel.

在分析罗拉斜齿顶面棕刚玉砂轮磨削缺陷的基础上，提出用立方氮化硼砂轮代替传统的棕刚玉砂轮进行磨削加工；确定CBN砂轮的构造特性和结构尺寸；设计CBN砂轮金刚滚轮修整装置；并对CBN砂轮修整参数进行深入分析研究。

ARM have numerous characteristics ,such as expansile system structure, low-power, low-cost and the support for real time multitask .Applying ARM to the design of medical instruments matches the trend that medical instruments are developing towards minimization and portability.

论文摘要： ARM具有体系结构可扩展、功耗低、成本低和支持实时多任务等特点，将ARM应用于医疗仪器的设计符合医疗仪器便携化、一体化的发展趋势。

With consideration of various analysis methods for reinforced embankment, the model of homogeneous earth slope is setup on the base of Finite Element Method. Using ANSYS-APDL language, the nonlinear finite element program for static analysis of the high reinforced embankments is made in this paper.

在综合考虑加筋路堤各种分析方法的基础上，利用ANSYS的APDL语言，建立了基于有限元法的加筋路堤参数化模型，编写了对加筋路堤进行稳定性分析的非线性有限元程序，并且综合各种影响因素对加筋路堤结构进行优化设计。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐