Natural Frequencies of Turbine Blades Connected Loosely by Tie-Wires

Abstract

In order to calculate the natural frequencies of turbine blades connected loosely by tie-wires, a blade-group model. in which five kinds of springs are inserted between the connecting points of blade and tie- wire, is introduced. A procedure for calculating the natural frequencies of the model is obtained by a transfer matrix method. The effects of each spring constant on the natural frequencies are clarified by applying the calculation procedure on actual turbine blade-group. Then the five spring constant of the blade-group are estimated and discussed according to the comparison of calculated and measured natural frequencies.