Development of transducers to measure the velocity reduction of materials at flexural wave numbers
Patrick J. Klippel, D. H. Trivett, A. Mark Young · The Journal of the Acoustical Society of America · 1998
A major noise source for velocity sensors in a hull array configuration is back plane (i.e., hull flexural vibration) noise. The level of back plane noise is a function of frequency and wave number, and depends upon the velocity reduction properties provided by a pressure release decoupling baffle. The Naval Undersea Warfare Center, Division Newport, has designed, constructed, and tested two Flexural Wavenumber Transducers capable of measuring the velocity reduction of materials. One is designed to characterize materials along the flexural branch, in vacuo, of a thin steel plate supporting quarter-scale experiments and the other along the flexural of a thick steel plate supporting full-scale evaluations. Both transducers operate within an environmentally controlled pressure vessel allowing velocity reduction measurements to be made over a wide range of temperatures and hydrostatic pressures. Both the design and experimental results will be presented. [Work supported by PEO(USW)/ASTO, Code D3 and ONR, Code 334.]