【摘要】 针对大型双曲冷却塔的自振特性问题,采用有限元方法进行计算分析,以某典型塔为例分析自振频率和振型的分布特点,并进行冷却塔自振特性的变参数分析,最后拟合得基频和倾覆频率的计算公式。分析表明:冷却塔的基频与混凝土材料参数槡E/ρ、筒体厚度成线性递增关系,与高度成反比,与人字柱总截面面积和子午线退化参数呈二次曲线关系。拟合公式与实测结果吻合较好,说明其在预测冷却塔自振频率方面具有较高可信度。更多还原

【Abstract】 The paper uses the finite element method to study the vibration characteristics of large hyperbolic cooling towers.Taking a typical tower for example,the distribution of the natural frequencies and mode shapes are investigated.The equations to estimate the fundamental frequency and overturning frequency are fitted based on a series of parametric studies.The results show that the fundamental frequency is directly proportional to the concrete material propertyE/ρ and the thickness of tower wall,and inversely proportional to the height of tower.The fundamental frequency also has a quadratic relationship with the total cross-sectional area of supporting columns and the median regressive parameter.The good matches between the results from the fitting equation and the results from full-scale tests indicate that the fitting equation has a high credibility in predicting the natural frequencies of cooling towers.更多还原