| 1. | High frequency approximate solution of wave equation of bit vibration source in seismic while drilling
随钻地震钻头震源波动方程的高频近似解法 |
| 2. | On the basis of above , identification method on vibration source correlation of multi - input and multi - output system is studied
并在此基础上,研究了根据多输入多输出系统,在振源相关时的辨识方法。 |
| 3. | Use vibration motor as vibration source . it is smooth in running and convenient in maintenance . the noise is low and the life is long
振动源是采用振动电机驱动,运转平稳,维修方便,噪音低,寿命长。 |
| 4. | And the state of art of the study on self - vibration characteristics , dynamic response and vibration sources of workshop structures is introduced
还介绍了我国对厂房结构的自振特性、动力响应分析、振动振源的研究现状。 |
| 5. | It is very difficult to solve the problem to make several frequency stagger the frequency of the main vibration sources with the experience analysis method
在设计空间受到多种限制下，要使厂房的多阶频率同时与振源频率错开，给经验试算的分析方法带来了很大的困难。 |
| 6. | The diesel engine is a complicated machine with many vibration sources , so the traditional vibration analysis and single parameter test method cannot determine the diagnosis accurately
摘要柴油机结构复杂，振源众多，常规的振动分析及单项指标测试对于故障的定位与诊断精确度不高。 |
| 7. | The nonstationary vibration sources that are mutually independent can be effectively identified by using the nonstationary blind source separation method from the multi - channel fault vibration signals
对于多通道的设备故障振动信号，应用非平稳信号的盲源分离算法，可以有效地提取各自独立的非平稳振动源，从而可以准确地进行机械故障诊断。 |
| 8. | With the input of a vibration acceleration history of subway train , a full dynamic analysis of soil - pile - structure is carried out . the propagation of vibration wave on the ground and vibration responses of the huge platform and the storied buildings are analyzed . some conclusions are drawn as follows : ( 1 ) with the increase of the distance to the vibration source , vibration intensity of the ground decreases ; ( 2 ) the vibration intensity of the ground in vertical direction is slightly larger than that in horizontal direction ; ( 3 ) with the increase of the distance to the vibration source , the situation that the vibration intensity of each building in horizontal direction is maximum at highest and lowest story whereas minimum at the middle story changes gradually to that decreasing with the height of building ; ( 4 ) in vertical direction , the vibration velocities and accelerations at the end points of each story of a building are the nominal identical , which indicates that the vertical vibration of them is unanimous ; ( 5 ) the vibration intensity in vertical direction of a building is larger than that in horizontal direction ; ( 6 ) increasing of the elasticity of track is an effective way to abate vibration of ground and buildings
本文以北京地铁八王坟车辆段地上超大结构(车辆段大平台及其上的小区楼房)及其地基基础为研究对象，在研究和分析有关资料的基础上，用快速拉格朗日有限差分法软件flac建立了二维数值分析模型，并以列车振动加速度时程作为模型输入，进行了地基?桩基础?地上结构的整体动力学分析，分析了地铁列车运行产生的振动在地面的传播规律及其对地上结构的影响，得到了如下结论： ( 1 )随着与地铁线路距离的增大，地面的振动强度有减小的趋势； ( 2 )地面竖直方向的振动强度较之水平方向的略大； ( 3 )随着与振源距离的增大，在水平方向上，地上各幢楼房的振动强度由底层和顶层的最大、中间层的最小逐渐过渡到沿楼层增高而减小； ( 4 )在竖直方向上，每幢楼各层端点的振动速度、加速度完全相同，表明楼房各层在竖直方向上的运动状态一致； ( 5 )各幢楼房竖直方向的振动强度比水平方向的大； ( 6 )增加轨道弹性是减轻地面和地上建筑振动的有效途径。 |
| 9. | Based on that the model is built in reason , many optimum model are built , the possibility that the second frequency staggers the vibration sources when the first frequency has staggered the vibration sources with many object optimum design method , the results under the most possibility are made . the acuity curves of every structure parameter to frequency
在合理建模的基础上，提出了多种优化模型，采用多目标优化方法，证明了每种优化模型一阶频率错开禁区情况下，二阶频率错开禁区的最大可能性，得到了在此情况下的最优解，很多分析表明，优化往往得到经验试算意想不到的结果。 |
| 10. | In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal , wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station , in which the signal is decomposed into different frequency band , and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基于李家峡水电站双排机组振动的现场试验研究，并且针对传统频谱分析方法傅立叶变换( fft )对于非平稳信号已力不从心这一缺陷，利用小波分析方法在时域和频域上同时具有良好的局部化性质，通过对开停机这一典型非平稳过程信号进行小波及小波包分析，将其分解到不同频带内，获取微弱信息和提取优势频率，并对其作振源分析，得出开停机初始时刻因水流不稳均出现强烈的振动现象，且低频段信号能量最大，开停机过程水流脉动压力和尾水涡带摆动是引起定子基础振动的主要原因。 |
