Optimization of material thickness distribution in single and double partition panels for maximized sound insulation

In this work, we propose a method to optimize the material thickness distribution of partition panels for maximized sound insulation while constraining material usage. A framework is developed to couple structural optimization with diffuse field sound transmission loss (STL) predictions based on deterministic-statistical energy analysis (Det-SEA). The methodology can handle the design of both single panels, including a single mechanical plate, and double panels, in which two mechanical plates are separated by an air cavity. Three formulations of the optimization problem are developed and compared in terms of final obtained performance and computational cost. In the first formulation, the resonance dips in the STL are suppressed by pushing the panel eigenfrequencies as far away as possible from the target frequency. In the second and the third formulations, the diffuse STL of the panel is directly maximized respectively at the target frequency and in a frequency band around the target frequency. The practical advantages of the method are investigated for different target frequencies in the audible range and for relevant design cases, such as the suppression of the STL dip located around the critical frequency of single panels and around the mass-spring-mass resonance frequency of double panels. For single panels, all three different formulations lead to significant insulation improvements, with no big differences in the final obtained performance. For double panels instead, we show that simply suppressing the resonance dips with the first formulation does not lead to adequate insulation improvements, but a direct maximization of STL is needed.

Automated summary

In this work, a method is proposed to optimize the material thickness distribution of partition panels for maximum sound insulation while controlling material usage. The method combines structural optimization with diffuse field sound transmission loss (STL) predictions. It is applicable to both single panels and double panels. The method demonstrates significant improvements in sound insulation for various target frequencies and design cases.