【摘要】 声黑洞(ABH)效应是通过将板结构厚度按特定规律改变以逐渐降低振动波在板内的传播速度,从而实现将能量聚集于某特定区域的现象;ABH近年来在控制结构振动和噪声方面得到较多的研究。以排列有(2×2)个声黑洞单元的板结构为研究对象,通过射线声学理论建立了在其等效二维板结构中弯曲波传播的轨迹模型;探讨了不同入射角度下声黑洞结构对弯曲波的聚焦位置;发现当声黑洞单元最小厚度不为0时,其聚焦位置可能不在声黑洞单元的几何中心;对此类声黑洞单元板使用多个动力吸振器(DVA)进行振动控制并采用数值搜索技术对其进行参数优化;在此基础上,研究了动力吸振器的放置位置对减振效果的影响。通过对比发现,参数优化后的动力吸振器在峰值处及其附近宽频带范围内均有非常显著的减振效果。更多还原

【Abstract】 The effect of acoustic black hole(ABH) is to gradually reduce velocity of vibration wave in a plate by changing the plate structure’s thickness according to a specific law to realize energy gathering in a specific region. In recent years, ABH has been studied more in fields of controlling structural vibration and noise. Here, the plate structure with 2×2 acoustic black hole elements was taken as the study object, the trajectory model of bending wave propagation in the original plate’s equivalent 2 D plate structure was established using the theory of ray acoustics. The focus position of bending wave caused by the acoustic black hole plate under different incident angles was explored. It was shown that when the minimum thickness of acoustic black hole element is not 0, the focus position of bending wave may not be at the geometric center of acoustic black hole element. Then, the vibration control of the plate with acoustic black hole elements was performed using multiple dynamic absorbers and their parameters were optimized adopting the numerical search technique. Furthermore, effects of dynamic vibration absorber(DVA) position on vibration reduction effect were studied. Through comparison, it was shown that dynamic vibration absorbers with optimized parameters can have very significant vibration reduction effect at their peaks and within a broadband range near their peaks.更多还原