【作者】 杜磊；

【导师】 陈美霞；

【作者基本信息】 华中科技大学 ， 船舶与海洋结构物设计制造， 2008， 硕士

【摘要】 传统的声学设计方法,往往是设计结构参数时,考虑声振性能不够,而更注重用贴敷阻尼材料、增加局部刚度、隔振、隔声等被动减振降噪技术处理,反复的实验和修改将造成设计和使用的成本增加,并且延长了设计周期。声学结构灵敏度是指声学参量对结构设计变量的导数,它表示了结构设计变量对声学参量的影响程度,因此有效的减振降噪方法是在设计之初就开展结构声辐射计算和声学—结构设计灵敏度分析(ADS),使设计人员能够了解怎样修改结构设计变量可以最有效地抑制结构振动及其辐射噪声,从而满足设计要求。另外对结构进行动力学优化,使结构固有频率避开振动敏感的频段,对优化结构的振动性能也具有很大的帮助。本文的主要工作包括:以有限元、边界元理论为基础,推导了声压、声功率结构声学灵敏度的计算公式。在结构频率响应分析的基础上,计算外肋圆柱壳振动速度对结构参数的灵敏度,然后将模型单元、节点参数文件以及振动速度的计算结果导入边界元软件,得到声学物理量对外肋圆柱壳厚度、肋骨高的灵敏度,并验证计算结果的可信度。分别用梯度法和马氏田口法对结构的固有频率进行了动力学优化。更多还原

【Abstract】 What the traditional way of acoustic design lack of is that it often put more attention on the other aspects but not the sound and vibration part. So when the structure parameters is already confirmed, but find that the acoustic-performance is not satisfied. At this time we have to reconsidered the structure parameters or use the passive reduction noise measures etc: add damping, enhance the structure stiffness and so on to meet our needs. This will increase the cost of experiment and extend the design cycle.ADS stands for the derivate of acoustic parameters to the design parameters. It simply represents the influence of the design parameters to the acoustic parameters. So the effective method of reducing vibration and noise must be calculate the ADS at the beginning it helps the engineers to know how to reduce the structure vibration and sound radiation. In addition dynamic optimization will help us to find out the sensitive frequency and avoid it. It will give a lot help also.At this paper, based on the theory of FEM and BEM, the natural frequency sensitivity, the frequency response displacement sensitivity, ADS is deduced. The structure sensitivity of the ring-stiffened cylindrical shell is calculated first. Then the model element information and result file is introduced to the BEM program to calculate the ADS and verify the reliability. Finally the gradient method and the DOE method is respectively used to do the optimization of the structure natural frequency.更多还原