Mode localization behavior and its generating mechanism of non-uniform rotating cylindrical shells

Rotating cylindrical shells are widely used in many engineering fields, and due to processing or other errors, nonuniform will happen from time to time, which will affect the vibration behaviors of the shell significantly. Therefore, in this paper, vibration analyses of non-uniform rotating cylindrical shells are carried out. The assumed mode method and Hamilton ' s principle are used to formulate the equation of motion. It is found that since the angular velocity tensor is an antisymmetric matrix, the damping matrix caused by the Coriolis force is also antisymmetric which in advance leads to traveling wave solutions. A method of expanding the assumed mode shape function to solve the traveling wave problem is proposed. Mode localization behaviors are found in the non-uniform cylindrical shells, and it is verified by the experiment. The generating mechanism for the mode localization is revealed. Moreover, mode veering is observed. The relationship between the model localization and mode veering is analyzed. In the fault diagnosis, inspired by the mode localization, a root mean square (RMS) curve method is introduced. The present study can provide a new idea for fault diagnosis of rotating cylindrical shells such as helicopter drive shafts.