ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF THE ACOUSTIC ENVIRONMENT OF THE RTD SONIC FATIGUE MAIN TEST CHAMBER
Rept. for 6 Mar 1963-15 Feb 1964
IIT RESEARCH INST CHICAGO IL
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The extreme versatility of the RTD Sonic Fatigue Facility creates problems in analysis and control of attainable environments. Acoustic environments have been analyzed using both theoretical and experimental modelling techniques, with regard to spatial distribution and correlation of sound pressures. A diffuse field study has enabled predictions of sound fields to be made for many cases of source and test structure parameters. Progressive-wave operation of the facility for small groups of sources was analyzed and some typical pressure field distributions were evaluated. The modifying effect on the progressive wave pressure fields, caused by locating test structures in these fields, was studied with respect to the size, location, and orientation of test-structures, the operational frequency of the source system and the relationship between the individual sources forming the overall system. Conditions were established for obtaining uniform, gradual, or rapid variations, and alternate maxima and minima in sound pressure level on the exposed surfaces of structures.