为了满足长叶片动频特性试验研究的需要，解决传统动频试验中传输速度慢、数据量小、抗干扰能力弱和集成化程度低的问题，基于数字传输技术，建立了基于数字信号的叶片动频特性试验体系，并运用设计的试验体系对某型长叶片进行了动频试验研究，获得了该型叶片的动频、三重点、围带调频性能等振动特性。试验结果表明：系统中采用的多通道采集，大幅度提高了数据传输量及系统集成化和数字化；相比于传统的动频试验方法，基于数字信号的叶片动频试验方法具有更强的载波信号强度和抗干扰能力，载波信号频率增大至2.4 GHz，信号带宽最大拓展至500 kHz。动频试验体系性能的提升可以更清晰地展现激振力谐波、叶片的固有频率、三重点峰值等特性，提升了三重点外推计算的准确性。

In order to meet the needs of experimental research on dynamic frequency characteristics of long blades and solve the problems of slow transmission speed,small amount of data,weak antiinterference ability and low degree of integration in traditional dynamic frequency experiment,based on digital transmission technology,this paper established a blade dynamic frequency characteristic experimental system which was used to carry out a detailed dynamic frequency experimental study for a certain type of long blade,and the vibration characteristics of this type of blade,such as dynamic frequency,three key points,shroud frequency modulation performance and so on,were obtained. The experimental results show that multichannel acquisition greatly improves the amount of data transmission and the integration and digitization of the system;the blade dynamic frequency experimental method based on digital signal has stronger carrier signal strength and antiinterference ability compared with the traditional dynamic frequency experimental method. The carrier signal frequency is increased to 2.4 GHz,and the maximum signal bandwidth is expanded to 500 kHz. The improvement of the performance of the experimental system can more clearly show the characteristics of excitation force harmonic,blade natural frequency and peak values of three key points,and improve the accuracy of three key points extrapolation calculation.

TK263.3

国家自然科学基金重点支持项目（U1809219）