高水头电站垫层式蜗壳自振特性分析

垫层蜗壳作为蜗壳结构形式中的一种,其结构形式复杂,内水压力传递比例不易控制,受力条件复杂,为分析探讨钢蜗壳在不同的垫层弹性模量和垫层包角作用下的自振特性,研究其自振频率与垫层弹性模量、垫层包角的关系,本文建立钢蜗壳的三维有限元模型,采用弹簧单元替代垫层和外包混凝土,考虑了垫层与钢板、混凝土与钢板接触效应,模拟了垫层和外包混凝土对钢蜗壳的作用。分析研究表明:钢蜗壳的自振频率随着垫层弹性模量的增大而增大,随着垫层包角的增大而减小,为机组的共振校核提供了一定的理论依据。

Analysis of self-vibration characteristics of cushion type volute chamber in high water head hydropower station

The cushion type rolute chamber is a form of spiral case structure,because of the complex configuration of spiral case of cushion layer and it is generally difficult to control the transfer ratio of internal water pressure.For the analysis of steel spiral case in different layer elastic modulus and cushion angle under the action of self-vibration characteristics,study on the natural frequency of the self-vibration and the elastic modulus of cushion package,angular relationship.In this paper,3D finite element model of steel spiral case was established by using a spring unit replacement cushion and the cushion and the simulation of concrete,considering the contact effects of steel and concrete,Simulation of cushion and concrete of steel spiral case role.Research shows that the natural frequency of vibration increases as the elastic modulus increases,decreases with the increase of cushion angle,the frequency can provide certain theory basis for the resonance vibration of unit.