结构声辐射有限元/边界元法声学-结构灵敏度研究

声学-结构灵敏度用于预测结构辐射声压随结构设计变量的变化,该值对结构降噪设计有重要意义。提出了基于有限元法、边界元法的声学-结构灵敏度计算方法。基于有限元法计算结构动力学响应及响应速度灵敏度,基于边界元法计算结构辐射声压及声压对振动速度灵敏度。将两个灵敏度联合,得到声学-结构设计灵敏度。以中空六面体为研究实例,给出了激励频率为1~100 H z时,外场声压对壳厚度的灵敏度,并分析了灵敏度随激励频率、设计变量的变化规律。结果表明,基于有限元法、边界元法的声学-结构灵敏度是有效和正确的。

Research on acoustic-structure sensitivity basing on FEM and BEM

Acoustic-Structure sensitivity is used to predict the change of acoustic pressure when structure design variable was changed,which is significance for reducing noise of structure.The acoustic-Structure sensitivities basing on both finite element method(FEM) and boundary element mend(BEM) are formulated and resented.The dynamic response and response velocity sensitivity with respect to structure design variable are carried out by use of structural FEM,and the acoustic response and acoustic pressure sensitivity with respect to structure velocity are carried out by use of acoustic BEM.Then,Acoustic-Structure sensitivity was evaluated with linking velocity sensitivity in FEM and Acoustic Sensitivity in BEM.This method is applied to a vacant box as an example.Acoustic pressure sensitivity with respect to structure thick is obtained in frequency ranges from 1 Hz to 200 Hz,and its changes along with stimulating frequency and design variable are analysed.Results show that acoustic-structure sensitivity method basing on FEM and BEM is effective and correct.