【作者】 韩彬；

【导师】 程远胜；

【作者基本信息】 华中科技大学 ， 船舶与海洋结构物设计制造， 2006， 硕士

【摘要】 结构振动控制是当前结构工程研究的热点之一,使用动力吸振器对结构进行振动控制是常用的非常有效的方法,本文研究了动力吸振器抑制结构声传递的机理,分别针对无限长梁结构和无限长板条结构,探讨了弯曲振动波在经过动力吸振器后的能量的变化。推导了无限长梁和无限长板条上使用一个或者两个动力吸振器时弯曲振动波的透射系数的计算公式,讨论了动力吸振器的质量、阻尼、固有频率、个数等参数对结构声传递抑制的影响。对于无限长梁结构,分别使用了控制平动和控制转动的不同形式的动力吸振器,提出了使用悬臂梁-质量块组成的摇摆式动力吸振器,并考虑了将控制平动的动力吸振器和摇摆式动力吸振器结合起来使用的情况。对无限长板条结构,采用了功率流方法定义和推导了弯曲振动波的透射系数。本文利用数学软件MATLAB进行编程计算,数值结果表明,动力吸振器的阻抑效果具有较强的频率选择性。无论是控制平动还是控制转动的动力吸振器,在所关心的激励频率范围内,其质量的增加对阻抑效果有利;阻尼的增加虽降低了最佳的阻抑效果,但能够使抑制的频带变宽,改善了阻抑效果的频率选择性;在总质量相同的条件下,多个动力吸振器的阻抑效果较单个的阻抑效果好。本文的研究工作为抑制结构声的传递提供了新的途径和方法。更多还原

【Abstract】 The impediment to propagation of a flexural vibration wave in structures using vibration absorbers was studied. The power attenuation of the flexural vibration wave with the effect of the vibration absorbers was discussed in an infinite beam and an infinite strip.The formulae of transmission coefficient for an infinite beam and an infinite strip with an incident flexural wave and impeded by one and two vibration absorbers were derived respectively. The effects of the mass, the damping, the natural frequency and the number of the vibration absorbers on impediment to structure-borne sound propagation were discussed. For the infinite beam, the absorbers suppressing the vertical motion of the structures and the absorbers suppressing the rotation of the structures were used separately and then jointly. For the infinite strip, the power flow was introduced in defining the transmission coefficient of the flexural wave in the strip.The numerical computations in this paper were achieved by the mathematical software MATLAB. Numerical results show that the impeding effect of the vibration absorbers reveals strong selectivity on frequency. Either for the absorbers suppressing the vertical motion of the structures or for the absorbers suppressing the rotation of the structures, increase in mass is good for the impeding effect. Increase in damping weakens the maximum impeding effect, but it widens the frequency band of impediment and improves the frequency selectivity accordingly. For the same total mass, the impeding effect of multiple vibration absorbers is better than that of single vibration absorber. This paper provides a new method on the impediment to structure-borne sound propagation.更多还原