Xi'an Jiaotong University

Zhibo Yang

Xuefeng Chen

Shaohua Tian

Laihao Yang

Ming Li

Wenbo Li

Jiahui Cao

Mingfeng Zhu

Haoqi Li

Xingwu Zhang

Zengkun Wang

The disclosure discloses a Lamb wave phased array focus-imaging method based on a frequency response function. In the method, a piezoelectric sensor array is arranged on a surface of a tested structure, the frequency response function of an excitation and acquisition pair formed by an excitation array element and an acquisition array element is calculated according to a full-band response signal, and a dispersion pre-compensation signal is constructed; the dispersion pre-compensation signal and the frequency response function are multiplied in a frequency domain to obtain a frequency domain pre-compensation response signal; and according to a distance from the acquisition array element to a focal point at the coordinates, the dispersion of the frequency domain pre-compensation response signal is post-compensated, so as to obtain a frequency domain dispersion post-compensation signal until all sensor excitation and acquisition pairs are traversed.

Lamb wave phased array focus-imaging method based on frequency response function

The present disclosure discloses a method for extracting a natural frequency difference between blades by a single blade tip timing sensor or uniformly distributed blade tip timing sensors. The method includes the following steps: acquiring actual arrival time of a rotating blade by using a single blade tip timing sensor or uniformly distributed blade tip timing sensors, and converting a difference between theoretical arrival time and the actual arrival time into displacement data of a blade tip according to a rotational speed and a blade length of the rotating blade; selecting displacement data of blade tips of two rotating blades with the same blade length at the same rotational speed; intercepting the displacement data, performing discrete Fourier transform respectively, and making a sampling frequency approximate to an average rotational speed to obtain spectrum data.

Method for extracting natural frequency difference between blades by single blade tip timing sensor or uniformly distributed blade tip timing sensors

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Shaanxi, China

Zhibo Yang