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71.
72.
《保鲜与加工》2002,(5):52-57
In this paper, a shaking table test for large-span underground structure is introduced. Based on the test, the frequency of inherent vibration, damping ratio and the dynamic response of the structure are studied. The response of the underground structure for vertical seismic excitation is studied as a key point. With the different imbedding depth, the influence of interaction of soil and structure on the earthquake-resistant capacity of the underground structure is discussed. 相似文献
73.
In order to study the vibration characteristics and radiation noise of wind power speed-increase gearbox, a torsional vibration model of wind power speed-increase gearbox is established based on the analysis of supporting stiffness of bearing and contact stiffness of gear pairs. By solving the vibration differential equation with the help of Matlab, the frequency and corresponding vibration mode are obtained. With taking stiffness excitation, error exaction and meshing impact exaction into account, the dynamic finite element model of speed-increase gearbox is set up, and the dynamic response simulation is carried out. Regarding vibration displacement of the nodes on gearbox surface as boundary condition, an acoustic boundary element model of speed-increase gearbox is built. The surface acoustic pressure of gearbox and the radiation noise of field points are solved by the direct boundary element method. The results show that there is a great difference between torsion frequency and excitation frequency of wind power speed-increase gearbox, and so the resonance doesn't occur. The maximum structural noise and radiation noise mainly appear near the double octave of the gears meshing frequency of high-speed grade. 相似文献
74.
75.
Gu Qiankun Tang Yike Yu Youju Xie Zhijiang Liang Xichang 《保鲜与加工》1997,(6):96-102
The dynamic characteristic of active isolation atuator on flexible foundations was studied under the installation of parallel structure and foundation cancellation.The influencing relationships between active isolation force of the different installation ways and passive isolation system and flexible foundation were analyzed and compared.Scientific basis for selecting installation ways of active isolator is provided in this paper. 相似文献
76.
Huang Wenzhen Huang Buyu Dong Xun 《保鲜与加工》1993,(1):72-77
Based upon the eigenvalue sensitivity theory of non-self-adjoit system and the component mode synthesis method,a new technique is developed to analyze the eigenvalue sensitivity to variation of parameters of large rotor-bearing system. As an application, the influence of the journal bearing parameters on the stability of a large domestic turbine-generator set is analyzed and discussed. 相似文献
77.
The turbogenerator vibration faults have the character of variety. Many faults often occur synchronously. This paper introduces a diagnosing model based on parsimonious covering theory and probability. A model for turtogenerator's fault diagnosis is proposed. The availability of this method is proved by two fault diagnosis examples of turbogenerator. The results show that the model proposed can be used for multi_fault diagnosis together. It may make up shortage for some of expert systems and neural networks in some aspect. From the practice,this model has higher reliability and practicability. 相似文献
78.
Zhang Xiangwei Xu Meihe 《保鲜与加工》1991,(4):8-15
The reliability of random vibration is discussed,and then by using the first order perturbation method and with the aid of relation of the systemic response function to the first order sensetivity of variable damp parameter, the rate of change of structural reliability indication is derived, therefore the constraint equation to guarantee reliability for the structural optimization design is proved and the satisfactory result is obtained,test and the practicability of this method is tested. 相似文献
79.
Zhu Caicao Wang Hongen Gong JianxiaoYu Shixing 《保鲜与加工》1993,(6):51-57
In this paper,the mill stand and the rolled piece were studied as a system. Based on the disoreted masses and the deformation of bending curve of the roller and roll housing, according to Rayleigh method,the equivalent mass and and the equivalent stiffness of the mode were solved,and set up a multiple degree of freedom vibration dynamic model. And also did theoretical analysis and calculation with an exapmle of the 4200 thick plate rolling mills. 相似文献
80.