Structural acoustics analysis and optimization of an enclosed box-damped structure based on response surface methodology

• The displacement field of structure is more effective to illustrate the reasons for causing the sound pressure in cavity.
• The positions where the pasted damping layers significantly affect the sound pressure are identified.
• The explicit function of sound pressure is obtained and the computational time of acoustic analysis is reduced enormously.
• The proposed explicit optimization model facilitates the optimization of the structural-born acoustics.

In this paper, the structural acoustics analysis and optimization of an enclosed box-damped structure are investigated by using the response surface methodology (RSM). Acoustic frequency response function analysis, i.e. a unit harmonic force imposing on structure and calculating the sound pressure in cavity, is applied to achieve the critical frequency. The acoustic sensitivity analysis of sound pressure level with respect to the thicknesses of damping layer panels are employed to identify the significant variables. With the help of faced central composite design, an efficient set of sample points are generated, and then the second order polynomial function of the sound pressure response at critical frequency is computed and verified by the adjusted coefficient of multiple determination. After the response surface function is verified, the effect of the thicknesses of damping layer panels on sound pressure is analyzed quantitatively, and the thicknesses of damping layer panels are further optimized to minimize the sound pressure response of the target node. The results indicate that, by using the RSM, the computational time for structural acoustic is saved and the optimization process is simple. The sound pressure of the target node is controlled effectively with less damping material used.

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