Abstract: In the design of ground gas turbine, the rod fastening rotor (bolted stacks rotor) is used. The rotor system consists of disks, stubs as well as circumferentially distributed tension rods. So far in the dynamic analysis of this kind of rotor in literatures, an integral rotor model is generally adopted. Sometimes the modified stiffness coefficient approach is also used to consider the effect of contacted interface. However the natural frequencies obtained from the above model are always higher than the observed ones. It is necessary to seek a more appropriate model to simulate it.A mechanical model is developed. It is considered to describe the mechanical behaviour of the interface where the component parts of the rotor are connected with each other. By using substructure coupling method, the theoretical analysis and numerical calculation of a laboratorial model rotor have been done. The natural frequencies of the rotor were also measured in laboratory. The coincidence between both results shows that the model presented here is effective.

Key words: rotor, rod fastening rotor, vibration characteristics, modal synthesis