【摘要】 突破了奈奎斯特采样定理的要求(采样率必须大于输入信号频率2倍的限制),将欠采样法应用于航空发动机构件的高频测量。通过叶片固有特性分析和在叶片上粘贴加速传感器两种方法,对欠采样法进行了验证;并在此基础上采用非接触激光位移传感器,实现了欠采样条件下频率较高的某型发动机涡轮叶片频率的准确测量。结果表明,欠采样方法应用于试件的固有频率测量切实可行,且在航空发动机构件的高频测量中有较大应用价值。更多还原

【Abstract】 The Nyquist sampling theorem astricts that the sample rate must be at least twice than the import signal frequency. The limit was broken and under-sampling method was applied to high frequency measure-ment of aero-engine components. The results were verified by both calculative analysis of inherent charac-teristics and test data from mounting an accelerometer on a turbine blade in the under-sampling conditions.Furthermore the blade frequency was accurately measured through a non-contact laser displacement sensorusing under-sampling method. It is proved that it is feasible to measure the natural frequency of specimenbased on under-sampling method and the method could be applied widely in high frequency measurementof aero-engine components.更多还原