工业厂房的防振设计

发布时间：2018-10-21 15:17

【摘要】：在有较大设备的选煤厂厂房中，机械振动在所难免。工业厂房在设计时容易出现共振现象，即使是较小的扰力也可能引起较大的结构振幅，使人产生不舒适感或对仪器的精密程度造成影响，盲目的加大梁的截面不一定会减小振幅，反而可能增加振幅，这是由于共振的影响。本文基于有限元软件SAP2000，应用时程分析方法对选煤厂的动力特性及动力响应进行计算。本文从结构动力特性的角度考虑，提出在设计过程中应如何改变结构的自振频率，以避免共振达到允许限值要求。通过研究得出以下结论：（1）厂房的自振频率以垂直向自振频率最高，水平向的自振频率要低于垂直向自振频率；（2）厂房的竖向频率比较密集，，会出现频率密集区。水平向频率比较稀疏；（3）对于厂房的竖向振动设计，其竖向质量参与系数最大所对应的频率值可能会引起共振，最危险；（4）振幅与振速随扰频变化的规律有大致相同的走向、趋势；（5）采用不同计算模型进行抗振设计的结果不同，根据工程实际情况或振源周边的不同情况选用计算模型，选用接近实际工程结构的梁板柱模型进行抗振设计更加合理；（6）在进行抗振设计时，应尽量使结构的扰频小于竖向基频，且结构的竖向频率与竖向质量参与系数最大所对应的频率值要远离扰频，一般即可满足限值要求，并建议一般将设备布置在主梁上；（7）对于扰频为16Hz的振动筛，使结构的竖向基频控制在16/0.75=21.3Hz以上，并且结构的竖向质量参与系数最大值所对应的频率尽量远离此值，结构一般不会发生共振；（8）机械作用下梁的刚度较大时，其共振频率接近结构的竖向参与系数最大所对应的频率值，机械作用下梁的刚度较小时，其共振频率接近结构的竖向基频，且振幅较大。所以在进行抗振设计时，尽量使机械作用下的梁的刚度大一些，而不需要把其余的梁均加大。
[Abstract]:Mechanical vibration is inevitable in the coal preparation plant with larger equipment. Industrial buildings are prone to resonance when they are designed. Even small disturbances may cause larger structural amplitudes, which may cause discomfort or affect the precision of the instrument. Increasing the beam section blindly will not necessarily reduce the amplitude, but may increase the amplitude, which is due to the effect of resonance. In this paper, the dynamic characteristics and dynamic response of coal preparation plant are calculated based on the finite element software SAP2000,. From the point of view of the dynamic characteristics of the structure, this paper puts forward how to change the natural vibration frequency of the structure in the design process so as to avoid resonance reaching the allowable limit. The conclusions are as follows: (1) the natural frequency of the factory building is the highest in the vertical direction, and the natural frequency in the horizontal direction is lower than that in the vertical direction, (2) the vertical frequency of the factory building is relatively dense. There will be frequency-intensive areas. (3) for the vertical vibration design of the powerhouse, the frequency corresponding to the maximum participation coefficient of vertical mass may cause resonance and is the most dangerous. (4) the variation of amplitude and velocity with perturbed frequency is approximately the same trend. (5) the results of anti-vibration design with different calculation models are different. According to the actual situation of the project or the different conditions around the vibration source, it is more reasonable to select the model of beam, slab and column close to the actual engineering structure to carry out the anti-vibration design. (6) in the design of anti-vibration, The perturbing frequency of the structure should be less than the vertical fundamental frequency as far as possible, and the frequency value corresponding to the maximum vertical frequency and the participation coefficient of vertical mass should be far away from the perturbed frequency, which could generally meet the requirements of the limited value, and it was suggested that the equipment should be arranged on the main beam. (7) for the vibrating screen whose scrambling frequency is 16Hz, the vertical fundamental frequency of the structure is controlled above 16/0.75=21.3Hz, and the frequency corresponding to the maximum vertical mass participation coefficient of the structure is far away from this value. (8) when the stiffness of beam under mechanical action is large, the resonance frequency is close to the frequency value corresponding to the maximum vertical participation coefficient of the structure, and when the stiffness of the beam is small, the resonance frequency is close to the vertical fundamental frequency of the structure. And the amplitude is larger. Therefore, in the design of vibration resistance, the stiffness of the beams under mechanical action is as large as possible, without the need to increase the rest of the beams.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU27;TU352

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