Sound reduction from vibrating thin plates using dimpling and beading design

• Published in: The Journal of the Acoustical Society of America 2012-09, Vol.132 (3_Supplement), p.1998-1998
• Main Authors: Myers, Kyle R., Alshabatat, Nabeel T., Naghshineh, Koorosh
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4755391

This study presents a design method to minimize the radiated sound power from vibrating beams and plates. The method relies on altering the acoustic characteristics of beam and plate structures passively by forming dimples and beads on their surfaces. The dimples and beads change the local stiffness of the structure without changing its mass. Also, they alter the mode shapes so as to reduce sound power. The vibration response of the dimpled and beaded beams and plates are calculated using the finite element method (i.e., ANSYS parametric design language). Then, the radiated sound power from vibrating structure is calculated based on the Lumped Parameter Model (LPM). Finally, the method of Genetic Algorithm (GA) is used to optimally locate and size the dimples or the beads on the plate to minimize the sound radiation. The sound radiation is minimized either at a single frequency, or over a broad frequency band. The results show that dimples or beads forming on thin beams and plates can achieve effective reductions in radiated sound power.