叶身裂纹对汽轮机叶片振动特性影响的研究

An Investigation on Effects of Blade Crack on the Vibration Characteristics of Steam Turbine Blades

探究了汽轮机叶片裂纹位置和裂纹深度对整圈叶片振动特性的影响。结果表明,随着裂纹深度的增加,整圈叶片的静位移幅值逐渐增大,一阶振动频率逐渐降低,单只裂纹叶片的个体振动愈发明显。当某一单只叶片完全折断后,该叶片附近的叶片将呈现自由振动。当裂纹位置由叶片底部向顶部变化时,整圈叶片静位移幅值先增大后减小,振动频率单调递增。研究内容为叶片裂纹识别和裂纹诊断提供了仿真依据,具有重要意义。

In this paper,the influence of crack location andcrack depth on vibration characteristics of steam turbine blades is investigated.The results show that,with the increase of crack depth,the vibration amplitude of the whole circle blades increases gradually,the first-order vibration frequency decreases gradually,and the individual vibration of the cracked blade becomes more obvious.When one single blade is completely broken,the vibration of the blades nearby turns to the free vibration.When the crack position changes from the bottom to the top of the blade,the first-order vibration amplitude of the whole circle blade increase first and then decrease,but the frequency increases monotonically.The present work provides a simulation basis for the identification and diagnosis on the blade crack,and is of great significance.