Structural elements with mathematically defined surfaces for enhanced structural and acoustic performance

Two design methods are explored to reduce vibration, minimize unwanted acoustic noise, and increase stiffness in structures. The first design approach is to create nearly isotropic panels with increased stiffness using two-dimensional curvature. These quasi-isotropic designs can be used in lieu of typical panel reinforcements, and can provide an inexpensive alternative to honeycomb sandwich designs. The second approach is to design panels formed into the shape of a mode shape to reduce detrimental modal dynamics. The effects of combining the two-dimensionally curved designs with constrained layer damping is also investigated. Further, it is also the goal of this research that these panels can be inexpensively manufactured with current manufacturing methods (e.g. stamping, rolling, thermoforming, etc.), resulting in a more effective structural element that does not require significant extra cost or weight. Initial analysis was performed using geometric modeling and finite element analysis. Experimental analysis involved both static and dynamic system identification. The experimental results indicate that quasi-isotropic designs can be accomplished with two-dimensional curvature.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• O'Sullivan, Donald Quinn, 1970-

Advisor dc:contributor.advisor

• Alexander Slocum.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8664

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8664