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本文建立了S0910轴承测振仪轴向加载部件的力学模型,并进行了数学推导,为轴承测振仪轴向加载部件的性能分析提供了理论依据。 相似文献
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本文建立了S091轴承测振仪轴向加载部件的力学模型,并进行了数学推导,为轴承测振仪轴向加载部件的性能分析提供了理论依据。 相似文献
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为了实现多频段射频信号的同时处理,提出了一种基于电容加载环形谐振器的双频可调谐带通滤波器。在对环形谐振器等效电路进行分析的基础上给出了可变电容加载的环形谐振器结构形式,实现了对谐振频率的调谐;然后对可调滤波器的端口电抗特性进行了分析,设计了实现双频可调谐滤波器;最后设计加工了工作于330~400 MHz之间的双频可调谐滤波器,两个通频带之间可以独立调谐,并且通带互相之间的影响很小。 相似文献
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基于小波能量和RBF网络的钢水下渣自动检测 总被引:2,自引:2,他引:2
由于采用振动监测的方法进行钢水连铸下渣检测时,通常在整个频段上很难获得钢水下渣这一突变信号。提出了一种基于小波能量和RBF神经网络相结合的钢水连铸下渣的自动检测方法。首先,利用小波包分析的高时频分辨特性将振动信号分解到各个频带上,并以各频带信号的能量来构造用于下渣检测的特征参数。然后,利用RBF神经网络实现正常浇铸和下渣信号的自动识别。实验表明,该方法可有效地进行下渣的自动检测。 相似文献
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目前EPS(电动助力转向系统)越来越多地应用在汽车中,因此对其寿命的估计就变得尤为重要。EPS测试系统主要分为两部分,分别为转矩加载部分和中间轴末端振动加载部分。针对前者,先进行转矩加载来源分析,并在此基础上搭建其动力学模型,再根据建模给出扭矩疲劳测试台的动力学描述,这将成为后续理论计算的根据,更好地为试验台的搭建提供理论基础,具有一定的实际意义。 相似文献
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通过对蝶式钢包回转台提升梁材料Q345B-Z15厚板焊接工艺分析,以及提升梁焊装难点、重点详细分析,采取了一些新型实用的方法,并阐述了该方法的要点。通过实际制作证明,采用此方法确保产品质量,降低了制造成本,缩短生产工期,为类似大型焊接件焊装积累宝贵经验。 相似文献
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《Measurement》2016
Conventional electroencephalography with disc electrodes has major drawbacks including poor spatial resolution, selectivity and low signal-to-noise ratio that are critically limiting its use. Concentric ring electrodes, consisting of several elements including the central disc and a number of concentric rings, are a promising alternative with potential to improve all of the aforementioned aspects significantly. In our previous work, the tripolar concentric ring electrode was successfully used in a wide range of applications demonstrating its superiority to conventional disc electrode, in particular, in accuracy of Laplacian estimation. This paper takes the next step toward further improving the Laplacian estimation with novel multipolar concentric ring electrodes by completing and validating a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ⩾ 2 that allows cancellation of all the truncation terms up to the order of 2n. An explicit formula based on inversion of a square Vandermonde matrix is derived to make computation of multipolar Laplacian more efficient. To confirm the analytic result of the accuracy of Laplacian estimate increasing with the increase of n and to assess the significance of this gain in accuracy for practical applications finite element method model analysis has been performed. Multipolar concentric ring electrode configurations with n ranging from 1 ring (bipolar electrode configuration) to 6 rings (septapolar electrode configuration) were directly compared and obtained results suggest the significance of the increase in Laplacian accuracy caused by increase of n. 相似文献
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Lokavarapu Bhaskara RAO Chellapilla Kameswara RAO 《Frontiers of Mechanical Engineering》2014,9(2):168-176
Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution. 相似文献
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This paper studies the vibration behaviour of circular Mindlin plates with multiple concentric elastic ring supports. Utilizing the domain decomposition technique, a circular plate is divided into several annular segments and one core circular segment at the locations of the elastic ring supports. The governing differential equations and the solutions of these equations are presented for the annular and circular segments based on the Mindlin-plate theory. A homogenous equation system that governs the vibration of circular Mindlin plates with elastic ring supports is derived by imposing the essential and natural boundary and segment interface conditions. The first-known exact vibration frequencies for circular Mindlin plates with multiple concentric elastic ring supports are obtained and the modal shapes of displacement fields and stress resultants for several selected cases are presented. The influence of the elastic ring support stiffness, locations, plate boundary conditions and plate thickness ratios on the vibration behaviour of circular plates is discussed. 相似文献
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根据一种新型环式减速器内的结构,利用ABQUS建立了有限元模型,并针对该减速器进行了模态分析,获得了内齿环板的振动频率及相应的振型特征;然后,进行了动力学稳态响应分析。为下一步进行新型环式减速器的改进及优化设计提供了可靠的依据。 相似文献
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Ship-Peng Lo Yeou-Yih Lin Jen-Ching Huang 《The International Journal of Advanced Manufacturing Technology》2007,34(5-6):547-555
During the chemical mechanical polishing process (i.e., CMP for short), it is expected to attain the requirement of global
planarization. However, the stress concentration, which occurred when approaching the wafer edge, has resulted in over-grinding.
The increasing material removal rate has also contributed to the wafer’s nonuniformity. In this paper, a retaining ring surrounding
the wafer carrier was added to the conventional CMP mechanism in order to improve the over-grinding phenomenon and avoid the
wafer sliding from the carrier as much as possible. The revolutions of the wafer and the pad were assumed to be the same,
and the force forms of the carrier and the retaining ring were axisymmetric uniformly-distributed. In addition, when the principle
of minimum potential energy was applied, a two-dimensional axisymmetric quasi-static finite element model for CMP including
the carrier, the retaining ring, the film, the wafer and the pad could be established. Following this model, the von Mises
stress distribution of the wafer surface without a retaining ring was analyzed to verify the model. The effects of the gap
between the ring and the pad and the ratio of the ring load and the carrier load on the stress and the wafer’s nonuniformity
were investigated. The results indicated that the von Mises stress distribution of the wafer surface was almost uniform near
the wafer center, and the maximum value appeared near the edge. The value decreased as the edge was approached, but it rose
again very close to the edge. Besides, the wafer’s nonuniformity would be prohibited while the gap and the load were designed
within the certain range to supply the retaining ring. 相似文献
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Lokavarapu Bhaskara Rao Chellapilla Kameswara Rao 《Frontiers of Mechanical Engineering》2013,8(3):291
This work presents the existence of buckling mode switching with respect to the radius of concentric rigid ring support. The buckling mode may not be axisymmetric as previously assumed. In general, the plate may buckle in an axisymmetric mode but when the radius of the ring support becomes small, the plate may buckle in an asymmetric mode. The optimum radius of the concentric rigid ring support for maximum buckling load is also determined. Introducing internal rigid ring support, when placed at an optimal position increases the elastic buckling load capacity by 149.39 percent. The numerical results obtained are in good agreement with the previously published data. 相似文献