SIMPLIFIED FINITE ELEMENT MODELLING OF ACOUSTICALLY TREATED STRUCTURES

✍ Scribed by M. Carfagni; P. Citti; M. Pierini

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 222 KB
• Volume: 204
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1995.0974

✦ Synopsis

The application of non-optimized damping and phono-absorbent materials to automotive systems has not proved fully satisfactory in abating noise and vibration. The objective of this work was to develop a simple finite element modelling procedure that would allow optimizing structures such as a car body-in-white in terms of vibroacoustic behavior from the design stage. A procedure was developed to determine the modifications to be made in the mass, stiffness and damping characteristics in the finite element (FE) modelling of a metal structure meshed with shell elements so that the model would describe the behavior of the acoustically treated structure. To validate the modifications, a numerical-experimental comparison of the velocities on the vibrating surface was carried out, followed by a numerical-experimental comparison of the sound pressures generated by the vibrating plate. In the comparison a simple monopole model was used, in which each area of vibrating surface could be likened to a point source. The simulation and experimental procedures, previously validated for the metal structure, were then applied to multi-layered panels. Good agreement between the experimental and simulated velocities and sound pressures resulted for all the multi-layered panel configurations examined.