HIGH FREQUENCY RESPONSE OF A STIFFENED BOX STRUCTURE

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Authors
  1. Gilroy, L.E.
  2. Smith, M.J.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
Power Flow Finite Element Analysis (PFFEA) has been under development at Defence Research Establishment Atlantic (DREA) in support of the Ship Noise Project. PFFEA is an analysis method for predicting high frequency structural acoustic and vibration response. The method is based on a vibrational conductivity approach in which the flow of vibrational energy is modelled in a similar fashion to heat conduction with convective losses. This report discusses experiments performed with DREA's ship tank test model to assist in the validation of the PFFEA software for high frequency structural vibrations. The experiments involved excitation of the steel box structure at relatively high frequencies using an electromagnetic shaker driving either the centre plate of the test model or one of three typical plate intersectons (a symmetric and unsymmetric T-plate junction and an L-plate junction) making up the structure. Both the input mobility to and the response of the test model were measured under broadband excitation using an accelerometer. The input mobilities predicted by the PFFEA code compared extremely well with the experimental measurements. While the power flow method is unable to accurately predict modal response (in this case frequencies up to about 3 kHz), the model accurately predicted the average behaviour for all four cases. TRUNCATED
Keywords
Power flow;Acoustics;Input mobility;Transfer mobility
Report Number
DREA-TM-98-227 — Technical Memorandum
Date of publication
01 Oct 1998
Number of Pages
115
DSTKIM No
99-00450
CANDIS No
510613
Format(s):
Hardcopy;Document Image stored on Optical Disk

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