环形基础振动频率的解析方法

Natural frequency analysis of annular foundations

储存液体结构的环形基础振动分析一直为人们所关注 .将环形基础简化为置于Winker地基上的曲线梁 ,提出了求解环形基础自振频率的解析方法 ,建立了曲线梁动力微分方程 ,推导出自振频率的表达式 .算例分析表明 :基频随半径增大呈波动变化趋势 ,并非单调减小 ,其频率是密集的 ;基频计算中扭转惯性力影响很小 ,可忽略不计 .这一结论对合理选择基础设计参数 。

The annular foundations of liquefied oil tank are simplified as a curve beam placed on Winkler foundations. An analytic way has been proposed to work out the nature frequency of annual foundations, a dynamic differential equation has been established for the curve beam, and an expression has beed formulated for the nature frequency. The calculated analysis shows that the frequency of the annual foundations varies with the increase of radius rather than decreasing monotonously and with dense frequency spectrum. In the calculation of the frequency of annual foundations, there is little torsion moment of inertia, and they can be neglected. This conclusion has great theoretical significance to the reasonable selection of the design parameters for the foundations as well as to the controlling of foundation vibration.