Numerical Investigation of Blade Packet Vibrations

Vibrations are the great hazard for state-of-the-art gas and steam turbomachine blading. To improve the vibration behavior of the turbomachine blading, the blades are connected into packets. The influence of such connection on blading dynamics is complex, and additional investigations are required for every single structure.In this paper, numerical vibration analyses of the blade packets are carried out using detailed three-dimensional finite element models. As such problems are complex and expensive to solve, a method, considerably reducing the cost of eigenproblem solution, is proposed. The efficiency of the technique described is achieved due to the assumption that the packeted blades are identical.The results of the vibration analyses of the single blade and the blade packets using the technique discussed are presented. The complexity of the vibration mode shapes is shown. The numerical efficiency of the approach is analyzed.Copyright © 1997 by ASME