汽机基础的抗震极限承载力及延性研究

发布时间：2018-04-28 05:46

本文选题：汽轮机基础 + 动力特性　；参考：《北方工业大学》2017年硕士论文

【摘要】：作为电力系统的核心,发电厂属于乙类抗震设防建筑,即在地震发生时其使用功能不能中断或者需要尽快恢复的建筑。汽轮发电机基础是发电厂承载汽轮发电机组的结构,其设计不仅要满足结构强度的要求还要满足设备安装的空间需求。鉴于其重要性及结构的复杂性和特异性,有必要对其抗震性能进行深入研究,进而为此类特殊复杂结构的创新设计与选型改进提供一定的参考。本文以某1000MW发电厂汽轮发电机基础为原型,依据相似定理,设计建造了 1:10的缩尺试验模型,并且对此汽轮发电机基础模型进行了以下试验研究:(1)对结构模型进行了动力特性试验,得到了结构振型、自振频率及阻尼比,分析了自振频率分布和振型特点。运用锤击法对汽轮机基础轴承支座处横梁进行了动刚度测试,验证了轴承支座在汽机动荷载作用下的运行稳定性。(2)对基础模型结构分别进行了 8度多遇和8度罕遇两个工况的拟动力试验,得到结构在地震作用下的响应,包括位移、加速度、钢筋应变、层间位移角及恢复力-位移曲线等一系列的抗震性能指标。(3)对基础模型结构进行了拟静力试验,对模型结构施加低周往复荷载,直到模型结构完全破坏。研究了模型结构在低周往复荷载作用下的破坏过程、塑性铰出现的位置、滞回曲线、骨架曲线、延性系数、极限承载力、刚度退化等抗震性能。本文对汽轮发电机基础的自振特性及抗震性能做了较全面的研究,通过试验分析可以得出,该汽轮机基础具有较好的抗震性能。研究结果可供地震区同类汽轮机基础做抗震设计时参考。
[Abstract]:As the core of power system, power plant belongs to class B seismic fortification building, that is, the building whose function can not be interrupted or needs to be restored as soon as possible when the earthquake occurs. The turbogenerator foundation is the structure of the power plant bearing turbine-generator unit. Its design not only meets the requirements of the structural strength but also meets the space requirement of the installation of the equipment. In view of its importance and the complexity and specificity of the structure, it is necessary to conduct a deep study on its seismic performance, thus providing a certain reference for the innovative design and type selection improvement of this kind of special complex structure. Based on the prototype of turbogenerator foundation in a 1000MW power plant, a 1:10 scale test model is designed and constructed according to the similarity theorem. The following experiments are carried out on the turbogenerator foundation model: 1) the dynamic characteristics of the structure model are tested, and the vibration mode, natural vibration frequency and damping ratio are obtained, and the distribution and characteristics of the natural vibration frequency are analyzed. The dynamic stiffness of the crossbeam at the bearing support of the basic bearing of steam turbine was measured by hammering method. The stability of bearing under the action of steam maneuvering load is verified. The quasi dynamic tests of the foundation model structure are carried out under two working conditions of 8 degree frequent and 8 degree rare, respectively, and the response of the structure under earthquake action, including displacement, is obtained. A series of seismic performance indexes, such as acceleration, reinforcement strain, interstory displacement angle and restoring force-displacement curve, are tested on the foundation model structure under low cycle reciprocating load until the model structure is completely destroyed. The failure process of model structure under low cycle reciprocating load, the location of plastic hinge, hysteretic curve, skeleton curve, ductility coefficient, ultimate bearing capacity and stiffness degradation are studied. In this paper, the natural vibration characteristics and seismic performance of turbogenerator foundation are studied comprehensively, and the experimental results show that the turbine foundation has better seismic performance. The results can be used as reference for seismic design of the same steam turbine foundation in earthquake area.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU476.1;TM621

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