Modal Parameter Extraction in Presence of Close Coupled Modes

Modal Parameter Extraction in Presence of Close Coupled Modes

In this research, modal properties and vibration response of a disk-like specimen with a small asymmetry, which causes close coupled modes, is identified by analysis of the modal impact test results. In order to achieve this goal, responses of the specimen to some impact loads to different locations are measured by a piezoelectric accelerometer and frequency response functions are calculated. Then using one and multiple degrees of freedom methods, modal properties of the specimen are identified. The correlation between measured FRF and regenerated one is studied and the results of the methods are compared with each other. Finally, the finite element model of the specimen is prepared and its responses are compared with the results of the modal test