Research on Automatic Test System of Engine Blade Natural Frequency

Blades are one of the important components on aircraft engines. If they break due to vibration failure，the normal operation of the entire engine will be offected. Therefore，it is necessary to measure their natural frequency before installing them on the engine to avoid resonance. At present，most blade vibration testing systems require manual operation by operators，which has high requirements for operators and the testing process is also very cumbersome. Therefore，the testing efficiency is low and cannot meet the needs of efficient testing. To solve the current problems of low testing efficiency and high operational requirements，a high-precision and high-efficiency automatic test system is designed. The testing accuracy of this system can reach ±1%，and the testing efficiency is improved by 37% compared to manual testing. Firstly，the influence of compression force and vibration exciter position on natural frequency test is analyzed by amplitude-frequency curve，so as to calibrate servo cylinder and four-dimensional motion platform. Secondly，the sine wave signal is used as the excitation to sweep the blade linearly，and the natural frequency is determined by the amplitude peak in the frequency domain. Finally，the accuracy experiment and efficiency experiment are carried out on the developed test system ，whose results verify its high efficiency and high precision. © 2024 Nanjing University of Aeronautics an Astronautics. All rights reserved.