Output-Only Experimental Modal Testing of Large Residential Structures and Acoustic Cavities Using Sonic Booms

In this thesis, an output-only experimental modal testing and analysis technique known as the Natural Excitation Technique (NExT) is examined for use with large residential structures and interior cavities. The technique which assumes a random, stationary input causing the response data is reviewed and extended for the first time to include the assumption of an impulse input. This technique is examined with respect to the experimental modal analysis of single and two room residential structures. Each structure is first tested using conventional modal testing methods. Then, NExT is applied using each structure's response to a simulated sonic boom, an impulsive input. The results of these analyses along with the results obtained from a finite element model are compared. Then, the interior cavities enclosed by the residential structures are examined using NExT. Therefore, this thesis also demonstrates the successful use of NExT on acoustic systems for the first time. Three configurations of the interconnected cavities enclosed by the two room structure are considered to study physical phenomena. Both interior pressure response to random, stationary inputs and the sonic boom response are used with NExT to determine modal properties. The results of these analyses are compared to a theoretical analysis. Advantages to using NExT with both the response to a random, stationary input and an impulsive input are demonstrated for structural and acoustic systems.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2010

Author dc:creator

• Corcoran, Joseph Michael

Chair dc:contributor.committeechair

• Burdisso, Ricardo A.

Committee members dc:contributor.committeemember

• Reichard, Georg
• Inman, Daniel J.

• acoustic cavity
• residential structure
• sonic boom
• Natural Excitation Technique (NExT)
• Modal testing

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-02232010-113639

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/31329