Experimental Mass and Frequency Mistuning ldentifica-tion of a Rotor Assembly

The main focus of this paper is to identify the frequency and mass mistuning patterns of a ro-tor assembly. Therefore, the Finite Element (FE) model is first validated with the results of the Experimental Modal Analysis (EMA) of the assembly. Then, the EMA is performed on the blades of both bladed disks compromising the assembly. By adding further mistuning to the bladed disks, it becomes possible to extract the frequency deviation patterns. The tuned blade is specified for each of the bladed disks based on the results. The relationship between the reference blade natural frequency and an additional mass value is obtained experimental-ly. The mass mistuning pattern is achieved for the impeller and the turbine wheel by imple-menting the function which fits the experimental data the best. Both of the extracted mistun-ing patterns, namely frequency and mass mistuning patterns are in agreement for the impeller and the turbine wheel. Furthermore, it has been demonstrated that the turbine wheel has high-er values of mistuning, which cannot be neglected if it is aimed to predict the vibrational re-sponses of the rotor assembly accurately

کلیدواژه ها:

bladed disk ، Experimental Modal Analysis (EMA) ، mistuning identification ، nat-ural frequency.