A hybrid IMSE-FE-BE method coupled with RSM for vibro-acoustic analysis and optimization of an I-shaped steel beam damped with constrained layer damping

In this paper, a method for calculating vibration and noise from the I-shaped steel beam damped with constrained layer damping (CLD) was proposed based on iterative modal strain energy (IMSE) method and finite element (FE)-boundary element method (BEM). Then, a series of hammer tests were carried out to obtain the typical vibro-acoustic response samples of a CLD-damped beam. It is shown that the calculated noise and vibration agreed well with the measured results, indicating that the proposed method is effective and accurate. Then, the response surface methodology (RSM) was used to analyze the influence of CLD-structural parameters on the sound radiation characteristics and natural frequency of the damped beam. With the objective of minimizing the acoustic radiation power, a program for finding the optimal CLD-structural parameters was developed based on interior penalty function method (IPFM). Finally, the acoustic response comparisons between the original bare beam and the optimized CLD-damped beam were performed. It shows that the overall sound power level was decreased from 98.12 dB to 80.47 dB, and the overall sound pressure level at measuring point S3-3 was reduced from 78.86 dB to 61.07 dB, demonstrating that the optimization of CLD-structural parameters can significantly improve the acoustic performance of CLD-structures.