Experimental modal analysis of the turbine blade

In this paper the results of an experimental modal analysis of the turbine blade were presented. Investigations were made using the electrodynamic vibration system. As the results of analysis, the resonant frequencies of the blade were performed. The results of experimental investigations are dependent on many parameters of vibration system defined before the start of the test. In the first part of this study the influence of the frequency sweep rate on values of blade resonant frequency was investigated. In the next part of the work the effect of excitation intensity on value of the blade vibration amplitude was investigated. The stiffness of the grip used for fixation of the blade to the movable shaker head can have a large influence on the results of an experimental modal analysis. The fir tree slots of the blade were compressed in the grip using a special screw with fine thread. In the last part of the work the influence of the torque used for screw home on results of the modal analysis of the blade was examined. As the results of performed investigations the final conclusions were formulated.

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