摘要
针对叶片运行中产生的疲劳裂纹会改变航空发动机振动特性及其频率转向、振型转换问题,建立航空发动机叶片有限元模型,基于结构模态振动理论研究裂纹参数,包括裂纹长度、裂纹位置变化对叶片固有振动及受迫振动特性影响;讨论频率转向区附近频率、振型变化规律。结果表明,裂纹长度、位置变化会逐渐改变叶片频率及振型,出现复杂的频率转向、模态耦合及振型转换特性,导致叶片同阶振动模态在不同裂纹长度、位置时具有不同的模态振型。
Fatigue cracks generated during operation would alter the aero-engine blade vibration characteristics, manifested as frequency veering and mode shape switching.Study on the frequency veering can lead us to a further understanding of the blade crack evolution process.After building the FEM of aero-blade,the influence of crack parameters （crack location and length）on blade natural vibration and forced vibration characteristics was studied based on structural modal vibration theory,focusing on the variation laws of vibration frequency and mode shapes in the vicinity of frequency veering area.The results show that crack location and length variation would affect the blade frequencies and mode shapes,and thus lead to complex frequency veering,mode coupling and mode shape switching characteristics, which explains why mode shapes alter with the variation of crack length and location in the same order of vibration mode.
出处
《振动与冲击》
EI
CSCD
北大核心
2014年第20期7-11,共5页
Journal of Vibration and Shock
基金
国家自然科学基金委员会与中国民用航空局联合资助项目(U1233201)
天津市科技支撑计划重点项目(13ZCZDGX00200)
关键词
航空发动机叶片
裂纹
振动特性
频率转向
振型转换
aero-engine blade
blade crack
vibration characteristic
frequency veering
mode shape switching
