Evaluation of different methods for the consideration of the effect of rotation on the stiffening of rotating beams

This paper addresses the problem of the rotating beam axial shortening modelling. The different methods for accounting for the rotating beam axial shoretning are used to develop four different models. The models are named as the potential energy model (PM), kinetic energy model (KM), and kinetic and potential energy model (KPM), in addition to the model that does not account for the axial shortening named as the consistent model (CM). The PM model accounts for the axial shortening in the form of added elastic potential energy that results from the virtual work done by the centrifugal force. In the KM model, the shortening effect is included in the velocity vector and the corresponding kinetic energy. Finally the KPM model combines both approaches. The results of analysis showed that the approach which handles both the effect of rotating speed and the effect of vibration amplitude for all modes correctly is the PM model. The KM model reflected softening behaviour that cannot be accepted physically by rotating structures for higher modes. Moreover, the combined KPM method showed in-correctness at low amplitudes that contradicts the linear theory.