大型预应力混凝土贮煤筒仓结构的地震作用有限元分析

Finite element analysis of large prestressed concrete silo structure under earthquake

利用有限元软件ANSYS,采用振型分解反应谱法和时程分析法分别计算了大型预应力贮煤筒仓结构的动力特性.研究表明:筒仓结构在质量和刚度分布上具有很好的轴对称性,无论是在满仓还是空仓工况下,第一、二阶振型均是自由振动的主要振型,且应力最大值均位于仓顶边缘设备集中荷载布置处,贮料能够显著降低筒仓结构的自振频率,对筒仓结构的动力特性影响极大.满仓地震时筒仓结构的变形和最大应力均比空仓地震时大,因此满仓状况下对筒仓结构抗震较为不利;在同一工况下采用振型分解反应谱法计算的仓顶最大位移和筒仓最大应力均大于时程分析法计算的结果.

To calculate the dynamic characteristics of large prestressed coal silo structure,the finite element software ANSYS is used,and in the modal decomposition response spectrum method and time history analysis method are used too.The research shows that:the silo structure has the very good in the mass and stiffness distribution of the axial symmetry,either in full or empty warehouse working conditions;the first and second order vibration mode is the main modes of free vibration;and the maximum stress concentrated load are located in warehouse top edge of the equipment layout.Storage has enormous influence on the dynamic characteristics of silo structure;by reducing the natural frequency of vibration of silo structure,significantly.The deformation and maximum stress of silo structure are larger than that of empty silo in the case of full storehouse earthquake.Under the same working condition,the maximum displacement and the maximum stress of silo roof calculated by the method of vibration decomposition reaction spectrum are larger than those calculated by the program analysis method.