Crack identification in a rotor with an open crack

• DOI: 10.1007/s12206-009-0814-5
• Publication Date: 2010-01-20T02:27:37Z
• Authors: Guang Ming Dong; Jin Chen
• Keywords: Identification; Flexibility method; Mode (computer interface); Helicopter rotor

A finite element (FE) model, which is based on a transfer matrix analysis and local flexibility theorem, is introduced for crack identification of a static (non-rotating) rotor with an open crack. Through numerical simulation, the effects of crack location and crack depth on the mode shapes and the changes in the eigenfrequencies of the cracked rotor are investigated. A crack identification algorithm that makes use of the translations of the first mode at two symmetric points and the contour diagram of crack location versus crack depth for the first two given normalized eigenfrequencies is proposed to estimate the crack location and depth in the rotor. Two illustrative examples are demonstrated and compared for availability and validity of the proposed algorithm.