Vibration Analysis of a Rotor Blades System on a Flexible Shaft

The vibration characteristics of the rotating blade-disc coupling structure mounted on a flexibleshaft is studied. The shaft flexibility is modelled as two lateral springs connected to thecenter of the disk which is assumed to have rigid body motion. Blades perform as classicalbeams and the structural model, which incorporates bending-bending-torsional flexibility,and also longitudinal flexibility is used. Linear equations of motion, composed of six coupleddifferential equations are derived using the Hamilton’s principal. The Galerkin method issubsequently applied to convert the partial differential equations into a set of ordinary differentialequations. Moreover, the numerical results are compared with published results andgood agreement is observed. Numerical simulations indicates the significant effects of the rotorangular velocity, rotor hub diameter and the design parameters such as the blades length and the blades pre-twist angle on the vibration frequencies

Keywords:

Blade-disk , rotor vibrations , vibration frequency