摘要
采用Patran软件建立了叶片三维实体模型,通过有限元软件Nastran研究了疲劳裂纹对叶片的固有频率及受迫振动响应的影响。为使结果更加敏感,分别计算未损叶片和裂纹叶片的前八阶固有频率并作平均,以此频率作为研究对象。结果表明:裂纹深度和位置对叶片频率影响很大,裂纹越深,频率越低;当裂纹远离叶片根部,叶片固有频率也增加。裂纹不仅使叶片固有频率下降,而且还引起受迫振动响应的非线性特征。
The 3D solid model of a blade is built by software Patran,and the natural frequencies and forced vibration characteristics of a blade with fatigue crack are determined by using the finite element method software Nastran.First eight natural frequencies were calculated for uncracked and cracked blades.One natural frequency was obtained by averaging the eight frequencies in order to get more sensitive results.The results indicate that the influence of depth and the location of the crack on natural frequencies are quite big.The deeper the crack is,the lower the blade＇s natural frequencies are;when the crack location goes far from the blade end,the natural frequencies also increase.The crack not only makes the blade＇ s natural frequencies decrease,but also causes the non-linear characteristics of forced vibration response.It is helpful for blade crack diagnosis and supervision.
出处
《机械科学与技术》
CSCD
北大核心
2010年第10期1385-1388,1392,共5页
Mechanical Science and Technology for Aerospace Engineering
关键词
疲劳裂纹
固有频率
非线性特征
有限元法
fatigue crack
natural frequencies
non-linear characteristics
finite element method
