The effect of failure of screw in the coupling connecting two compressor shafts on the dynamic behavior of the rotor in Rolls Royce gas turbine

In this study, the effect of failure of a screw in the coupling connecting two compressor shafts on the dynamic behavior of the rotor in The Rolls Roys gas turbine has been investigated. For this purpose, the geometric model of the compressor shaft was designed and Modal analysis was performed by finite element method by ANSYS and Campbell diagram were designed separately. Experiential Modal analysis and its comparison with numerical Modal analysis have been used to validate and confirm the designed model. It used the harmonic analysis of the shaft without blades and discs, as well as the shafts with blades and discs for the frequency response of velocity and displacement due to the failure of the screw connecting the two shafts at the edge and medial connection separately and synchronous. The results showed that the frequency response of the compressor shaft velocity in the coupling screw failure at the edge of the screw failure location is about 30% higher than the medial screw failure mode, indicating that the coupling screw failure in the edge has a greater effect on the shaft and rotor behavior in terms of velocity and displacement compared to the medial screw.