A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to sol...A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to solve the problem of poor low-frequency vibration isolation of the foundation under unbalanced excitation of shipboard equipment.Based on the finite element method,the influence of characteristic parameters of the foundation panel structure on its vibration reduction characteristics under unbalanced excitation is explored.The results show that the vibration isolation level of the impedance-balanced foundation is 10 dB higher than the traditional foundation in the low-frequency band of 10-500 Hz when subjected to combined excitation of concentrated force and moment.Increasing the thickness of the impedance-balanced foundation panel can enhance the isolation effect.Increasing the number of sub-panels can effectively reduce the vibration response of the foundation panel and enhance the isolation performance of the foundation.The connection stiffness between sub-panels has a small effect on the isolation performance of the foundation.展开更多
As a passive means of vibration reduction, particle damping is mainly applied to the horizontal or vertical steady field. However, it is seldom applied to centrifugal fields. Under high speed and heavy loading, the vi...As a passive means of vibration reduction, particle damping is mainly applied to the horizontal or vertical steady field. However, it is seldom applied to centrifugal fields. Under high speed and heavy loading, the vibration of tooth surfaces of gear transmissions becomes more severe shortening gear service life and augmenting noise. Under centrifugal loading, the particle system exhibits different characteristics, for example, particles are extruded at the end farthest from the center. We investigated gears with drilled via holes filled with damping particles. Using the discrete-element method, we developed an energy dissipation model for the particle system accounting for friction and inelastic collisions. Energy dissipation and damping characteristics of this system were analyzed. Experiments were also conducted with the gear system having different particle filling rates. The results show that this filling rate is an important parameter associated with particle damping in a centrifugal field. An unsuitable filling rate would significantly reduce damping effectiveness. With changes in rotation speed and load, the gear transmission system has different optimal filling rates. The results provide guidelines for the application of particle damping in centrifugal fields of gear transmissions.展开更多
基金funded by the National Natural Science Foundation of China(Grant Numbers.U2006229 and 52101351)。
文摘A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to solve the problem of poor low-frequency vibration isolation of the foundation under unbalanced excitation of shipboard equipment.Based on the finite element method,the influence of characteristic parameters of the foundation panel structure on its vibration reduction characteristics under unbalanced excitation is explored.The results show that the vibration isolation level of the impedance-balanced foundation is 10 dB higher than the traditional foundation in the low-frequency band of 10-500 Hz when subjected to combined excitation of concentrated force and moment.Increasing the thickness of the impedance-balanced foundation panel can enhance the isolation effect.Increasing the number of sub-panels can effectively reduce the vibration response of the foundation panel and enhance the isolation performance of the foundation.The connection stiffness between sub-panels has a small effect on the isolation performance of the foundation.
文摘As a passive means of vibration reduction, particle damping is mainly applied to the horizontal or vertical steady field. However, it is seldom applied to centrifugal fields. Under high speed and heavy loading, the vibration of tooth surfaces of gear transmissions becomes more severe shortening gear service life and augmenting noise. Under centrifugal loading, the particle system exhibits different characteristics, for example, particles are extruded at the end farthest from the center. We investigated gears with drilled via holes filled with damping particles. Using the discrete-element method, we developed an energy dissipation model for the particle system accounting for friction and inelastic collisions. Energy dissipation and damping characteristics of this system were analyzed. Experiments were also conducted with the gear system having different particle filling rates. The results show that this filling rate is an important parameter associated with particle damping in a centrifugal field. An unsuitable filling rate would significantly reduce damping effectiveness. With changes in rotation speed and load, the gear transmission system has different optimal filling rates. The results provide guidelines for the application of particle damping in centrifugal fields of gear transmissions.
