Competition and high quality requirements in the industries have necessitated the need for reliable rotating machines. This can be partly achieved by continuous monitoring of operation conditions to detect any fault before it causes serious problem or breakdown of rotating machines. The detection of faults in rotating blades via direct blade vibration measurements and analysis is somewhat difficult because blades often operate in a very harsh environment (gas turbine blades are rotating in high temperature and pressure environment). This paper presents indirect detection of blade faults from lateral vibrations of a rotor-disk-blade system, which can easily be measured, using laboratory test-rig. A rotor, disk, 6 normal blades and 3 blades with different defects were designed. The modal parameters of the normal and defective blades were determined experimentally and by modal analysis using ANSYS. The lateral vibrations, in the x- and y-axis, of the rotor-disk system with normal 6 blades and with 5 normal blades and 1 defective blade at a time were measured and analyzed. The results revealed that defective blades showed some distinct characteristics in the frequency domain, which can be used to identify blade faults in a bladed rotor-disk system.
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