A reduced-order dynamic model for an unbalanced rotor system is developed, taking the coupling between torsional and lateral vibrations into account. It is assumed that a shaft is regarded as a continuous viscoelastic...A reduced-order dynamic model for an unbalanced rotor system is developed, taking the coupling between torsional and lateral vibrations into account. It is assumed that a shaft is regarded as a continuous viscoelastic shaft with unbalanced and small deformation properties. The equations of motion for the torsional and lateral vibrations are derived using Lagrange's approach with the frequency-dependent shape function. The rotor torsional vibration is coupled with the lateral vibrations by unbalance elements in a way of excitations. Simulation and experiment results show clearly that the torsional vibration has strong impact on the rotor lateral vibrations, and it causes subharmonic and superharmonic excitations through unbalance elements, which leads to the superharmonic resonances in the lateral vibrations. This model with low-order and high accuracy is suitable for rotor dynamic analysis in real time simulation as well as for active vibration control syntheses.展开更多
We appreciate the comment from Horne,Miller and Wang on the paper‘A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation’by Liu et al.（2015）[1],f...We appreciate the comment from Horne,Miller and Wang on the paper‘A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation’by Liu et al.（2015）[1],for the opportunity to consider and clarify the group and phase velocity issue in sonic logging with a deviated borehole penetrating a VTI formation.We re-read the paper by Liu et al.[1]and did some numerical tests and analyses.展开更多
基金Project(51105017)supported by National Natural Science Foundation of ChinaProject(2011BAG09B00)supported by the National Science and Technology Support Program,ChinaProject(2010DFB80020)supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China
文摘A reduced-order dynamic model for an unbalanced rotor system is developed, taking the coupling between torsional and lateral vibrations into account. It is assumed that a shaft is regarded as a continuous viscoelastic shaft with unbalanced and small deformation properties. The equations of motion for the torsional and lateral vibrations are derived using Lagrange's approach with the frequency-dependent shape function. The rotor torsional vibration is coupled with the lateral vibrations by unbalance elements in a way of excitations. Simulation and experiment results show clearly that the torsional vibration has strong impact on the rotor lateral vibrations, and it causes subharmonic and superharmonic excitations through unbalance elements, which leads to the superharmonic resonances in the lateral vibrations. This model with low-order and high accuracy is suitable for rotor dynamic analysis in real time simulation as well as for active vibration control syntheses.
文摘We appreciate the comment from Horne,Miller and Wang on the paper‘A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation’by Liu et al.（2015）[1],for the opportunity to consider and clarify the group and phase velocity issue in sonic logging with a deviated borehole penetrating a VTI formation.We re-read the paper by Liu et al.[1]and did some numerical tests and analyses.
