Accession Number : ADA297653

Title :   Radiated Noise from a Three Dimensional Truss.

Descriptive Note : Master's thesis,

Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF OCEAN ENGINEERING

Personal Author(s) : Chiasson, Leo E., Jr

PDF Url : ADA297653

Report Date : SEP 1995

Pagination or Media Count : 101

Abstract : The Massachusetts Institute of Technology Truss Damping Group continues to study the dynamic and vibrational characteristics of a three dimensional aluminum truss which is based on a repeating square pyramidal pattern. The truss is a notional model of the type of structure which will be considered for use in the future design of submersibles and Autonomous Underwater Vehicles (AUV's) to mount machinery A current concern is in the ability to accurately predict the level of radiated noise which the truss will transmit to the environment inside the submersible due to an arbitrary vibrational loading.The noise produced could have unsatisfactory coupling effects with the fluid surrounding the submersible and could also produce unacceptable levels of noise inside. The vibrational energy in the truss members as a result of arbitrary loading is predicted using a previously developed numerical analysis technique known as the Direct Global Stiffness Matrix (DGSM) method. These vibrational levels are then used to calculate the radiated sound power, with the struts modeled as finite length vibrating wires. The sound power with the addition of flat plates to the truss is also modeled. (MM)

Descriptors :   *UNDERWATER VEHICLES, *TRUSSES, *RADIATED NOISE, *SUBMERSIBLES, *SUBMARINE NOISE, COUPLING(INTERACTION), VIBRATION, WIRE, MATRICES(MATHEMATICS), STIFFNESS, DAMPING, THESES, BENDING, THREE DIMENSIONAL, ALUMINUM, PATTERNS, MOUNTS, NUMERICAL METHODS AND PROCEDURES, ACOUSTIC VELOCITY, SUBMARINE HULLS, TRAVELING WAVES, TORSION, STRUTS, FLAT PLATE MODELS, PYRAMIDS(GEOMETRY).

Subject Categories : Submarine Engineering
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE