竖向减振弹簧结构的水平抗震性能研究

发布时间：2018-05-06 10:05

本文选题：弹簧隔振基础 + 自振特性　；参考：《北方工业大学》2015年硕士论文

【摘要】：汽轮发电机组是发电厂的核心设备,随着我国电力建设的快速发展,大功率汽轮机得到越来越多的使用,为改善机组的运行环境,采用弹簧隔振基础是非常有效的方法。由于隔振弹簧将台板与基础下部结构完全隔开,隔振弹簧对基础整体结构的自振特性及地震响应势必产生较大影响。模型试验能够形象、真实、直接地反映出基础的动力特性和地震响应,从而检验结构是否满足抗震设计要求。本文以某汽轮发电机组弹簧隔振基础为研究对象,设计制作了1：8的试验模型,通过模型试验对弹簧隔振基础的隔振及抗震性能进行了研究。具体工作如下：按照设计图纸及相似关系进行1：8缩尺模型的设计与制作。采用三点随机激振、空间响应测量的方法对基础进行动力特性试验,获得了基础的自振频率、振型和阻尼比。分析基础的自振频率和振型特点可知,采用弹簧隔振器使基础的自振频率明显降低,成功避开了设备的工作频率的同时,还避开了地震的卓越周期。按照力的传递系数的定义进行传递系数的测试,隔振效果良好。由于本文采用的测试方法没有刚性台板的假定,所以比假定为单自由度体系的简化计算方法更合理。通过7度多遇地震和罕遇地震作用下的拟动力试验研究了汽轮机基础的抗震性能,测得了基础的钢筋应变、位移、速度、加速度和恢复力响应时程,以及滞回曲线、裂缝的开展情况、层间位移角等。试验结果证明,在地震作用下,减振弹簧基础符合《建筑抗震设计规范》标准,达到了弹簧减震的目的。
[Abstract]:Turbine-generator unit is the core equipment of power plant. With the rapid development of electric power construction in our country, high-power steam turbine is more and more used. In order to improve the operating environment of the unit, it is very effective to adopt spring vibration isolation foundation. Since the vibration isolation spring completely separates the platform plate from the substructure of the foundation, the vibration isolation spring will have a great influence on the natural vibration characteristics and seismic response of the whole foundation structure. The model test can reflect the dynamic characteristics and seismic response of the foundation directly and vividly, so as to verify whether the structure meets the requirements of seismic design. Taking the spring vibration isolation foundation of a turbogenerator unit as the research object, the 1:8 test model is designed and made in this paper. The vibration isolation and seismic performance of the spring isolation foundation are studied by the model test. The specific work is as follows: Design and manufacture the 1:8 scale model according to the design drawings and similar relations. The dynamic characteristics of the foundation are tested by means of three point random excitation and spatial response measurement. The natural vibration frequency, mode shape and damping ratio of the foundation are obtained. Based on the analysis of the natural frequency and mode characteristics of the foundation, it can be seen that the spring vibration isolator can obviously reduce the natural vibration frequency of the foundation, thus successfully avoiding the working frequency of the equipment and avoiding the excellent period of the earthquake at the same time. According to the definition of force transfer coefficient, the effect of vibration isolation is good. Since the test method adopted in this paper does not have the assumption of rigid plate, it is more reasonable than the simplified calculation method which is assumed to be a single degree of freedom system. The seismic behavior of steam turbine foundation was studied by quasi dynamic tests under frequent and rare earthquakes. The response time history of steel bar strain, displacement, velocity, acceleration and restoring force and hysteretic curve were measured. The development of cracks, interstory displacement angle and so on. The test results show that the vibration absorption spring foundation meets the standard of Building Seismic Design Code under earthquake action and achieves the purpose of spring damping.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU435;TU476.1

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