Mistuning analysis of bladed disk consisting of directionally solidified blade (Vibration response analysis by use of response surface method and FMM)

Abstract

Recently, DS (Directionally Solidified) and SC (Single Crystal) alloys have been widely applied for gas turbine blades instead of CC (Conventionally Casting) alloys. The SC blade consists of one columnar grain, and the DS blade consists of several columnar grains of SC, where the growing direction of the columnar crystal is set to the direction of the centrifugal force. The frequency deviation of the DS blade caused by the deviation of the material property seems to become larger than that of the CC blade, because of the number of the independent elastic constants more than the CC blade, the deviation of the elastic constants due to the deviation of the crystal growing direction, and so on. Therefore, the mistuning characteristics of the bladed disk consisting of the DS blades seem to be different from that of the CC blade. In this study, the mistuning analysis of the bladed disk consisting of the DS blades are carried out, considering the deviations of the elastic constants and the crystal angle of the DS blade. The FMM is used to analyze the mistuned bladed disk. The maximum amplitude of the mistuned bladed disk of the DS blade is estimated by the Monte Carlo simulation combining with the response surface method, and the calculated results are compared with those of the CC blades.