Dynamic modelling strategy of a shaft-disk-blade coupling system integrating beam and shell theories

Despite the remarkable success achieved in modelling the rotor-disk-blade coupling system, the existing research does not adequately consider both the structural flexibility and the rotating effects in the shaft, disk, and blade components. To bridge this gap, a dynamic modelling strategy has been developed for the shaft-disk-blade coupling system using an in-house code that integrates the Timoshenko beam and Mindlin-Reissner shell elements. In addition, two critical issues concerning the couplings of the shaft-disk and disk-blade are successfully addressed by using the penalty method in conjunction with the compatibility equation of deformation. Subsequently, the improved modelling strategies for the shaft-disk coupling system, with and without blade components, are verified by comparing their static/dynamic frequencies and modal shapes with those obtained from experiments and solid models in ANSYS. The results indicate that the beam-shell hybrid model exhibits good accuracy and high efficiency in simulating the dynamic characteristics of the shaft-disk coupling system with and without blades. The modal characteristics of the entire rotor system have a series of flexible vibration modes, including bending/torsion/axial mode for the shaft, pitch diameter/umbrella-type mode for the disk, and bending mode for the blade.