【摘要】 柔性梁结构是水下航行器的常见部件，其模态振动传递会损害部件服役寿命和系统工作精度。常见的抑制梁振动的方法有吸振、阻尼和主动控制等。控制的难点在于低频抑振和拓宽有效抑制频带。而常见的抑振方法的应用需要获取准确的结构参数和激励参数，对于非完备参数条件系统的适用性不足。本文基于时变边界结构的能量传递特性，提出了一种针对模态振动抑制的时变边界方法。该方法可同时抑制多阶共振，而不必针对每阶振动特性进行额外设计。首先，建立时变边界梁的动力学模型，采用时域分段解析法计算时变边界梁的瞬态振动，并与有限元法的结果进行对比验证了该方法的正确性。然后，通过时变边界梁和固定边界梁的结果对比验证了时变边界方法对共振的抑制效果。最后，分析初始条件、阻尼、时变范围和时变频率等参数对时变边界方法抑振效果的影响，发现阻尼可消耗由模态振动分散至其他频域的能量，时变边界所对应的谐振频率变化范围越大时，对共振峰值的抑振性能越好，并由此得到了时变位置优化区域。更多还原

【Abstract】 As common components in huge underwater gliders, modal vibrations of flexible beams can affect the durability of structures and the precision of system. The current methods for suppressing the beam vibrations include the damping suppression, active control and absorbers, etc. The above control methods were gradually developed for the low frequencies and wide band. The accurate structures and excitation parameters should be obtained in the design processing. In this work, a time-varying boundary method is proposed based on the energy transfer phenomenon of timevarying boundary structure. The proposed method is effective for suppressing multi-order structure resonance simultaneously. A dynamic model of a time-varying boundary beam is established. The vibrations of time-varying boundary beam are obtained by a time-domain piecewise analytical method, which are compared with those from a finite element software. The vibrations of time-varying boundary beams and time-invariant beams are compared. The vibration suppression effect of time-varying boundary method is verified. The effects of the damping, time-varying range and timevarying speed on the vibration suppression characteristics are analyzed. The time-varying position optimization area is obtained. Note that the time-varying boundary method can simultaneously suppress the multimodal resonances of beam and reduce the resonance peaks with the highest energy.更多还原