【作者】 陈艳娇；

【导师】 黄志龙； 罗银淼；

【作者基本信息】 浙江大学 ， 工程力学， 2008， 硕士

【摘要】 自然通风冷却塔是火电厂的重要建筑物之一,其安全性是关系到国家经济发展的重要问题。冷却塔在自然界中受到自重、风压、地震、温度等因素综合作用,其抗震性设计是尤为重要的一个方面。目前对冷却塔抗震动力特性主要是用有限元方法计算,本文结合振动台试验及有限元法计算,综合研究有机玻璃冷却塔模型及钢架冷却塔模型的抗震性,这在实际工程应用中具有重要意义。本文基于1:200缩尺比例的两种冷却塔模型,研究其固有特性及在地震激励下的动力响应。具体内容为:用锤击试验法测得两种模型的频率及阻尼,并与有限元计算结果比较分析;计算有机玻璃冷却塔模型在EL-centro、Koyna及松潘地震波激励下的瞬态响应及反应谱响应;将有限元法计算与振动台试验法结合,研究了钢架冷却塔模型在两种周期加速度激励下的动力学响应,并对结果比较分析。最后可以得到结论:有限元法计算得到的部分模态可在锤击试验中识别;冷却塔在EL-centro地震波下时程响应极值比Koyna及松潘地震波作用下的时程响应极值要大,与谱分析结果相当,因此对模型的时程响应分析是必要的;在各类加速度激励下,塔壳体下端支柱附近的内力及应力响应较大。本文首次在国内用有限元分析法及模型试验法相结合初步研究冷却塔的动力响应,所得结果对冷却塔抗震设计有指导意义。更多还原

【Abstract】 Natural draft cooling tower is an important construction in power plant and its safety concerns economic development greatly. In nature, cooling tower is influenced by gravity, wind pressure, earthquakes and temperature, in which seismic-resistance is an important aspect. At present, most research on dynamics of cooling tower is based on FEM. However in this thesis, vibration experiment and FEM calculations are all used to research seismic-resistance of organic model and steel model, which is meaningful in practical engineering applications.Two cooling tower models of 1:200 reduced-scales are built to make analysis of model properties and dynamic responses. First, natural frequencies and damping are measured by hammering experiments, comparison with the results of ANSYS calculations are made. Transient responses and spectrum analysis responses of organic cooling tower model under EL-centro, Koyna and song seismic waves are calculated by ANSYS. At last, dynamic responses of steel cooling tower model under two periodic incentives are analyzed by using ANSYS and vibration experiments, also make comparison. The results showed that: some modes in ANSYS are recognizable in experiments. The responses of organic cooling tower model under EL-centro seismic wave are bigger than the other two and are similar to results of spectrum analysis, so time history response analysis are necessary. Motivated by various acceleration incentives, responses of the supporting columns are bigger.It is the first time that finite element analysis and vibration experiments are used together to research the responses of cooling tower initially, the results can give some guide to seismic responses design.更多还原