Characterization of crack on the outer edge of the disk based on blade tip timing technology

Abstract

The structural performance failure of the rotating blade disk with disk crack is one of the major causes of aero-engine failures and even serious accidents. The blade tip timing (BTT) is a non-contact measurement technology that obtains the rotor operation status by detecting the blade. This paper has proposed a crack characterization method for the disk’s outer edge based on the BTT technique. In this process, the influence of crack state parameters (length and position) on the circumferential displacement signal of the blade tip is determined by using the crack tip displacement, the relative position of the blade tip motion during the rotation of the outer edge crack-containing disk and the actual blade tip measuring points, and the critical value of the crack state parameters affecting the blade tip offset is analyzed. The finite element simulation results verify the effectiveness and accuracy of the proposed method. The study of this article can provide a theoretical basis for the measurement of cracks on the disk’s outer edge by the BTT technique, which is of great significance for the accurate identification of the operating condition of the rotating blade disk structure.